---------------------------------------------------------- Europa-List Digest Archive --- Total Messages Posted Mon 06/27/11: 31 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:41 AM - Popham Europa International Fly in (Steven Pitt) 2. 01:28 AM - Re: Woodcomp after Sales Service (houlihan) 3. 01:34 AM - Re: Re: Best device to ratify the Actual Fuel Flow on a 914 (G-IANI) 4. 02:15 AM - Re: Woodcomp after Sales Service (David Joyce) 5. 02:56 AM - Another Propeller Question (Kingsley Hurst) 6. 04:02 AM - Re: Another Propeller Question (Pete Lawless) 7. 04:02 AM - Europa XS monowheel 3D dxf file (smartieb) 8. 04:04 AM - ULPower 260i in Europa (smartieb) 9. 04:37 AM - Re: Woodcomp after Sales Service (Jos Okhuijsen) 10. 04:58 AM - Re: Woodcomp after Sales Service (David Lewendon) 11. 05:13 AM - Woodcomp after Sales Service (Guerner Remi) 12. 06:12 AM - Woodcomp after sales service (Fergus Kyle) 13. 06:54 AM - Re: Woodcomp after sales service (Jos Okhuijsen) 14. 06:57 AM - Re: Europa XS monowheel 3D dxf file (Paul McAllister) 15. 07:22 AM - Re: Woodcomp after Sales Service (PHILLIPS I) 16. 07:33 AM - Re: Woodcomp after Sales Service (PHILLIPS I) 17. 07:38 AM - Re: Woodcomp after Sales Service (Mark Burton) 18. 08:13 AM - Re: Europa XS monowheel 3D dxf file (G-IANI) 19. 10:43 AM - Re: Woodcomp after Sales Service (David Joyce) 20. 12:23 PM - Re: Woodcomp after Sales Service (Stephan Cassel) 21. 12:42 PM - Re: Re: Woodcomp after Sales Service (Jos Okhuijsen) 22. 01:09 PM - Re: Re: Woodcomp after Sales Service (nigel henry) 23. 01:46 PM - Re: Woodcomp after Sales Service (kees de bussy) 24. 02:20 PM - Re: Re: Woodcomp after Sales Service (Karl Heindl) 25. 02:29 PM - Re: Another Propeller Question (glenn crowder) 26. 02:42 PM - Re: Re: Woodcomp after Sales Service (Frans Veldman) 27. 02:48 PM - Re: Re: Woodcomp after Sales Service (Robert Borger) 28. 04:12 PM - Re: Woodcomp after Sales Service (Mark Burton) 29. 04:15 PM - Re: Another Propeller Question (JR Gowing) 30. 04:27 PM - Re: Re: Woodcomp after Sales Service (Jos Okhuijsen) 31. 05:13 PM - Re: Re: Woodcomp after Sales Service (Jos Okhuijsen) ________________________________ Message 1 _____________________________________ Time: 12:41:41 AM PST US From: "Steven Pitt" Subject: Europa-List: Popham Europa International Fly in Just over a week to go for our second International fly in at Popham starting Friday 8th July. A hog roast has been ordered for Saturday after the AGM so all are welcome to join in the fun. Space is available for tents either with or without your aircraft (but preferably with!!) Lets see if we can get over 50 Europas together this year. It is hoped that we can carry out some trial flights for prospective purchasers and friends over the weekend so if anyone is happy to volunteer can they let me know off list please. Regards Steve Pitt, Dave Bosomworth and the Committee of the Europa Club ________________________________ Message 2 _____________________________________ Time: 01:28:38 AM PST US Subject: Re: Europa-List: Woodcomp after Sales Service From: houlihan Hi Jos. Thanks for your prompt reply. I think you have cleared up my problem I could not see how a limit switch failure could cause the blade angle to change if the blade was within its normal operating range. Yes a limit switch failure could allow the blade to travel beyond its normal limit but the pitch change motor would still have to be driven ( commanded or uncommanded ) to move the blades beyond their normal range. This was the part I did not understand. As the Smart controller in its normal ie not in manual control, acts as a closed loop servo system with a given engine RPM as its target it should have increased the pitch as the RPM approached the target, I may be wrong but I would NOT have expected the blades to reach their fine pitch limit at that phase in the flight . As to my expertise I do not claim to be an expert in anything at all. But I do have experience, I was trained by the Royal Air Force as an airborne radar technician and spent ten years ( admittedly forty years ago !) working in what was then Signals Command on a electronic counter measures squadron. On leaving the Air Force I was for seven years a Flight Trials Engineer with British Aerospace military aircraft division commissioning developing and maintaining what was then the worlds first digital airborne data acquisition system. In later years I worked on large format printing systems using both analogue and digital servo systems. We have to accept that homebuilt aircraft are not as reliable and safe as a fully certified one and we therefore take on extra risk with our types of aircraft. In the UK we try minimise the risk by having our association double check that our alterations from the standard design appear to be safe and the changes are justified. You mention the RPM reached 6,200 just a little story I was told by a friend who is no longer with us. He operated out of a small strip and set his propeller to reach max RPM of 5,800 and flew it like that for some years he then had reason to have his RPM gauge calibrated and found that what he thought was 5,800 was actually 6,200. his gauge had never been calibrated and was under reading Enjoy your second life Jos best regards Tim H On 26 June 2011 23:46, josok-e wrote > Tim, > > I've sent the report to somebody who is German en fluently in English, on > his offer to translate. This translation takes an incredible amount of time > obviously. > But, as a matter of fact, the investigator thanks me for diverting from my > line of descent into an occupied office building to trees. The wreckage was > badly burnt. He also reports that he had Woodcomp check the remains of the > propellor, and that they stated that the blades "must have been at a flyable > angle" Also there was no obvious fault with the engine. It has not been > possible to determine what the cause of the accident was. You may doubt of > course that i have summarized properly as well. > Significant might be also that after the accident Rotax was the first to > talk to me, smartavionics next, the factory was very interested also. But no > question, no word from Woodcomp. > > I find it strange that you start an argument by telling us that you are not > an expert. And reach a conclusion, which is false. I am an expert, > electricity, electronics have been my profession and hobby. I know > microswitches and diodes, and if i tell you they are grossly underrated and > not up wet conditions, you can take my word for it. > > My only interest is to save your lives. If you don't want it, please let me > know. > > So, let me explain how the prop ended in a non-flyable position, so simple > that a non-expert can understand. I commanded via the controller to go > finer. That makes the motor run the blades to fine. The motor runs then as > long as the controller command it to go finer or the fine limit switch cuts > the current. In this case, because the desired rpm was high, and i was > climbing, the fine limit switch should cut in. But it didn't because it was > burnt, and short circuited to earth. The controller reversed it voltage to > increase pitch and we had a short circuit on the plus now. The > circuitbreaker popped. The revs went to 6200, with no pull. Attempting to > reset it booted the controller. Which proved it was still working, And after > the boot it popped again, The accident conditions were there, low on > altitude, low on speed. > > I find it amazing that people defend such a product. Everybody i spoke to > privatly admids there have been problems with communication, with quality of > parts, with forgotten or loose parts, splitting blades, whatever. Oh, of > course, they will cut the blades in a banana form, or apple, or anything > else you fancy as fast. Very flexible indeed. > > There is a good working product available, has been for years, factory > choice, with only plusses but the price. > Everybody makes a mistake, and i can admit it was my mistake to go on the > cheap and settle for a Woodcomp. > > Regards, > > Jos > > > 27.6.2011 0:25, houlihan kirjoitti: > >> Hi >> Further to Jos's comments about his very serious accident I seem to recall >> that the Austrian authorities planned to issue a report regarding the >> possible cause. I may have missed it so can anyone let me know what it >> contained, preferably in English. >> Not being an expert in these things I find I have problems linking the >> limit switch failure Jos talks about to the fact that for the propeller to >> go to fully fine or even beyond fully fine to a beta state requires the >> motor to be powered to drive it there. I am sure there may be a mechanism >> that will make that happen but I cannot see how it can do that just because >> a limit switch fails. >> Also my understanding is that Woodcomp do not support the Smartavioncs >> controller not surprising really as it is not their product and it is in >> competition with them but " banning" it is beyond their remit. >> Tim H >> >> On 26 June 2011 20:10, Jos Okhuijsen > josok-e@ukolo.fi>> wrote: >> >> Hi >> >> >> Sorry to remember you all that my Woodcomp prop nearly took my life. >> >> I hate to repeat my words, but memories seem to be short. >> The propeller i had was equipped with microswitches, which were >> and ,after a change, still are not designed for outside use. >> Nethertheless these switches are mounted on the backplate, open >> for weather. >> These switches are designed for AC 240 V, not for DC 12 V, and the >> Amp rating is way below the current going through them. >> The cross-over diodes are specified for less then half the current >> drawn. >> Even when activated only occasionally, it's a design flaw. >> >> Know to me are 3 incidents with short circuiting micro-switches, >> both other pilots could land their plane without damage to their >> plane or themselves. An incident with a loose gear, causing one >> of the blades at a totally diffent angle then the others was >> reported to me, and never made it to this forum. This seems to be >> the happy family show, which i am now spoiling. :-( >> It may well be that there are others, or people never fly in rain. >> or are just very lucky. >> >> In my case, to the best of my knowledge, a microswitch short >> circuited, taking the prop to a feather situation, shortly after >> take-off. I had been flying in heavy rain for hours the other day. >> >> Unless thing have changed is Jyrki the only one who understands >> English, if he's not available you are on your own. >> >> After my incident Woodcomp banned the Smart Avionic controller. >> What that means is unclear to me. As far as i know, they never got >> there own controller working decently. >> >> As for the figures, i've had trouble to keep up with a 912 with a >> fixed prop and i was flying with a 914 and a Woodcomp 3000. The >> only good figure seems to be the price. >> >> So in short: Save a few, risk your plane and life. >> The choice is yours.... >> >> Regards, >> >> Jos Okhuijsen >> (enjoying his second life :-) >> >> . 26.6.2011 19:16, Frans Veldman kirjoitti: >> >> --> Europa-List message posted by: Frans >> Veldman> >> >> >> On 06/26/2011 04:02 PM, Paul McAllister wrote: >> >> I was very impressed with the results that David Joyce got >> with his SR >> 3000W propeller from Woodcomp. I would like to some >> feedback from the >> forum about there after sales experience from Woodcomp. >> Please give me >> the 'good, the bad and the ugly' >> >> I got excellent support and advice when I was ordering the >> propeller >> from Woodcomp directly and delivery was prompt. After that I >> had no >> reason to contact them again as the prop works flawlessly and >> performs >> better than expected. Had to service it at 50 hours and did >> that at a >> local Woodcomp dealer. Found that one spinner screw was >> missing and got >> a complete new spinner fastening set free of charge. Ordered spare >> brushes, but at the 100 hour check I discovered that the >> brushes were >> almost like new and it looks like it is going to take a long while >> before I have to replace them. >> >> Have now 100+ hours but have had no issues with the prop. >> A few notes though: >> 1) I'm using the controller from Smart Avionics which is very >> configurable and able to match the prop exactly to the >> engine/airframe >> characteristics. >> 2) I have a prop with feather capability (to anticipate a >> potential >> future use of the glider wings). The props with feather >> capability have >> a stronger and faster motor. Maybe this is the reason why the >> Woodcomp >> prop behaves like a hydraulic prop and reacts so fast that it >> never >> allows the RPM to surge off its target. >> >> Hope this helps, >> >> Frans >> >> >> >> >> >> >> ==============================**===== >> target="_blank">http://www.**matronics.com/Navigator?**Europa-List >> ==============================**===== >> http://forums.matronics.com >> ==============================**===== >> le, List Admin. >> ="_blank">http://www.**matronics.com/contribution >> ==============================**===== >> >> >> >> >> * >> >> >> * >> > > ________________________________ Message 3 _____________________________________ Time: 01:34:01 AM PST US From: "G-IANI" Subject: RE: Europa-List: Re: Best device to ratify the Actual Fuel Flow on a 914 Scott Thank you for bring this to my attention. I have been waiting 3 months for an MGL FF1 with the FT60 sensors. I e-mailed the UK agent yesterday to ask again about progress. On my last enquiry (about 6 weeks ago) the reply was he was waiting for a reply from the manufacturer. Your note probably explains the delay as they are probably having to revise the software/hardware to fix the problem I will let you know why I hear more Ian Rickard G-IANI XS Trigear, 300hours Europa Club Mods Specialist e-mail g-iani@ntlworld.com -----Original Message----- From: owner-europa-list-server@matronics.com [mailto:owner-europa-list-server@matronics.com] On Behalf Of sblack Sent: 27 June 2011 05:07 Subject: Europa-List: Re: Best device to ratify the Actual Fuel Flow on a 914 I have the mgl ff1 and the ft60 red cube and there is a snag. The ft60 has a k factor of 68000 but the ff1 only allows k factors up to 60000! Have you dealt with this Ian? Thanks Scott -------- Scott Black Montreal Jodel F11 O-200 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=344189#344189 ________________________________ Message 4 _____________________________________ Time: 02:15:22 AM PST US From: "David Joyce" Subject: Re: Europa-List: Woodcomp after Sales Service Jos, I count you as a good friend but have to dispute many of your statements. I also will state that I am no expert, but nevertheless am a very interested amateur prepared to go to great lengths to get to the bottom of something that affects my safety, ( and having said that Tim did spend a lot of years as a radar/ electronics technician in the RAF). I have on the other hand been a sort of unofficial (but unpaid I hasten to add) Woodcomp agent in the UK having brought (and bought) the first Woodcomp prop into the UK and then pursued the very lengthy process of getting it fully accepted by the PFA. As you know I was there at the accident, with the same plane and the same controller and the same SR3000 (albeit without the reverse option). I flew back to try to help you and subsequently examined the wreckage and spent some time helping the Austrian AAIB man. As the accident happened flying out of the Rotax Factory Flyin it's not surprising that they were quickly able to help. Secondly since Mark Burton, owner of Smart Avionics,was flying with us he was quick to talk to the investigator. I may say that I gave the investigator my copies of the Smart Avionics controller and SR3000 handbooks and allowed him to look at the complete workings of my set up which was the official factory set up of an SR3000 without the reverse option that you had and without the non Woodcomp/personal simplifications to the wiring system that you had incorporated into the circuitry. There wasn't too much left of the plane after the fire but the prop hub was there and it was apparent that the blades were close to zero pitch, so that regardless of how they got there it would be safe to say that a similar accident could not happen with an SR3000 that does not have the reverse option (which is not accepted by the LAA following your accident), as the standard props have not only electronic stops at the fine limits but also mechanical ones. My understanding of the investigation was that no prime cause could be positively identified, and if I do not misquote him I believe this is also Mark Burton's view (who is also of course an electronics professional.) The microswitches have changed over the years largely to improve their mechanical security but whether they are waterproof or not seems a bit irrelevant. I have flown through prolonged rain and found no problems, and you would expect that any water finding its way into a structure rotating at 2000+ rpm would very rapidly find its way out again. If you had parked the plane under a waterfall and the spinner was full of water before start up you might expect to notice problems when you switched on and went though the recommended pitch change check. You refer to the problem experienced by someone having some teeth break on the gearing that determines the pitch angle of each blade and this was promptly dealt with by Woodcomp replacing it both on new models and retrospectively with a slightly heavier version of the gears. Woodcomp certainly have no problem about the Smartavionics controller which is the choice of the majority o f the substantial number of UK Woodcomp owners. Apart from your problem I have not come across problems that were not of the failsafe variety, and feel that describing the prop as a deathtrap is entirely unwarranted Regards and best wishes David, G-XSDJ You mention ----- Original Message ----- From: "josok-e" Sent: Sunday, June 26, 2011 11:46 PM Subject: Re: Europa-List: Woodcomp after Sales Service > Tim, > > I've sent the report to somebody who is German en fluently in English, > on his offer to translate. This translation takes an incredible amount > of time obviously. > But, as a matter of fact, the investigator thanks me for diverting from > my line of descent into an occupied office building to trees. The > wreckage was badly burnt. He also reports that he had Woodcomp check the > remains of the propellor, and that they stated that the blades "must > have been at a flyable angle" Also there was no obvious fault with the > engine. It has not been possible to determine what the cause of the > accident was. You may doubt of course that i have summarized properly as > well. > Significant might be also that after the accident Rotax was the first to > talk to me, smartavionics next, the factory was very interested also. > But no question, no word from Woodcomp. > > I find it strange that you start an argument by telling us that you are > not an expert. And reach a conclusion, which is false. I am an expert, > electricity, electronics have been my profession and hobby. I know > microswitches and diodes, and if i tell you they are grossly underrated > and not up wet conditions, you can take my word for it. > > My only interest is to save your lives. If you don't want it, please let > me know. > > So, let me explain how the prop ended in a non-flyable position, so > simple that a non-expert can understand. I commanded via the controller > to go finer. That makes the motor run the blades to fine. The motor runs > then as long as the controller command it to go finer or the fine limit > switch cuts the current. In this case, because the desired rpm was high, > and i was climbing, the fine limit switch should cut in. But it didn't > because it was burnt, and short circuited to earth. The controller > reversed it voltage to increase pitch and we had a short circuit on the > plus now. The circuitbreaker popped. The revs went to 6200, with no > pull. Attempting to reset it booted the controller. Which proved it was > still working, And after the boot it popped again, The accident > conditions were there, low on altitude, low on speed. > > I find it amazing that people defend such a product. Everybody i spoke > to privatly admids there have been problems with communication, with > quality of parts, with forgotten or loose parts, splitting blades, > whatever. Oh, of course, they will cut the blades in a banana form, or > apple, or anything else you fancy as fast. Very flexible indeed. > > There is a good working product available, has been for years, factory > choice, with only plusses but the price. > Everybody makes a mistake, and i can admit it was my mistake to go on > the cheap and settle for a Woodcomp. > > Regards, > > Jos > > > 27.6.2011 0:25, houlihan kirjoitti: >> Hi >> Further to Jos's comments about his very serious accident I seem to >> recall that the Austrian authorities planned to issue a report >> regarding the possible cause. I may have missed it so can anyone let >> me know what it contained, preferably in English. >> Not being an expert in these things I find I have problems linking the >> limit switch failure Jos talks about to the fact that for the >> propeller to go to fully fine or even beyond fully fine to a beta >> state requires the motor to be powered to drive it there. I am sure >> there may be a mechanism that will make that happen but I cannot see >> how it can do that just because a limit switch fails. >> Also my understanding is that Woodcomp do not support the Smartavioncs >> controller not surprising really as it is not their product and it is >> in competition with them but " banning" it is beyond their remit. >> Tim H >> >> On 26 June 2011 20:10, Jos Okhuijsen > > wrote: >> >> Hi >> >> Sorry to remember you all that my Woodcomp prop nearly took my life. >> >> I hate to repeat my words, but memories seem to be short. >> The propeller i had was equipped with microswitches, which were >> and ,after a change, still are not designed for outside use. >> Nethertheless these switches are mounted on the backplate, open >> for weather. >> These switches are designed for AC 240 V, not for DC 12 V, and the >> Amp rating is way below the current going through them. >> The cross-over diodes are specified for less then half the current >> drawn. >> Even when activated only occasionally, it's a design flaw. >> >> Know to me are 3 incidents with short circuiting micro-switches, >> both other pilots could land their plane without damage to their >> plane or themselves. An incident with a loose gear, causing one >> of the blades at a totally diffent angle then the others was >> reported to me, and never made it to this forum. This seems to be >> the happy family show, which i am now spoiling. :-( >> It may well be that there are others, or people never fly in rain. >> or are just very lucky. >> >> In my case, to the best of my knowledge, a microswitch short >> circuited, taking the prop to a feather situation, shortly after >> take-off. I had been flying in heavy rain for hours the other day. >> >> Unless thing have changed is Jyrki the only one who understands >> English, if he's not available you are on your own. >> >> After my incident Woodcomp banned the Smart Avionic controller. >> What that means is unclear to me. As far as i know, they never got >> there own controller working decently. >> >> As for the figures, i've had trouble to keep up with a 912 with a >> fixed prop and i was flying with a 914 and a Woodcomp 3000. The >> only good figure seems to be the price. >> >> So in short: Save a few, risk your plane and life. >> The choice is yours.... >> >> Regards, >> >> Jos Okhuijsen >> (enjoying his second life :-) >> >> . 26.6.2011 19:16, Frans Veldman kirjoitti: >> >> --> Europa-List message posted by: Frans >> Veldman> >> >> On 06/26/2011 04:02 PM, Paul McAllister wrote: >> >> I was very impressed with the results that David Joyce got >> with his SR >> 3000W propeller from Woodcomp. I would like to some >> feedback from the >> forum about there after sales experience from Woodcomp. >> Please give me >> the 'good, the bad and the ugly' >> >> I got excellent support and advice when I was ordering the >> propeller >> from Woodcomp directly and delivery was prompt. After that I >> had no >> reason to contact them again as the prop works flawlessly and >> performs >> better than expected. Had to service it at 50 hours and did >> that at a >> local Woodcomp dealer. Found that one spinner screw was >> missing and got >> a complete new spinner fastening set free of charge. Ordered >> spare >> brushes, but at the 100 hour check I discovered that the >> brushes were >> almost like new and it looks like it is going to take a long >> while >> before I have to replace them. >> >> Have now 100+ hours but have had no issues with the prop. >> A few notes though: >> 1) I'm using the controller from Smart Avionics which is very >> configurable and able to match the prop exactly to the >> engine/airframe >> characteristics. >> 2) I have a prop with feather capability (to anticipate a >> potential >> future use of the glider wings). The props with feather >> capability have >> a stronger and faster motor. Maybe this is the reason why the >> Woodcomp >> prop behaves like a hydraulic prop and reacts so fast that it >> never >> allows the RPM to surge off its target. >> >> Hope this helps, >> >> Frans >> >> >> >> >> >> >> =================================== >> target="_blank">http://www.matronics.com/Navigator?Europa-List >> =================================== >> http://forums.matronics.com >> =================================== >> le, List Admin. >> ="_blank">http://www.matronics.com/contribution >> =================================== >> >> >> >> >> * >> >> >> * > > ________________________________ Message 5 _____________________________________ Time: 02:56:53 AM PST US From: "Kingsley Hurst" Subject: Europa-List: Another Propeller Question Is there anybody out there who has an NSI VP propeller with a constant speed controller of any sort? OR does anybody know what sort of CS controller would work on an NSI VP prop? Any comments most welcome. Thanks Kingsley in Oz. ________________________________ Message 6 _____________________________________ Time: 04:02:17 AM PST US From: "Pete Lawless" Subject: RE: Europa-List: Another Propeller Question Hi Kingsley Mark Burton, Smartavionics, has a generic version of his cs unit that he says should work with an NSI. I talked to him about it a year or two back when I was thinking of adding CS. Regards Pete -----Original Message----- From: owner-europa-list-server@matronics.com [mailto:owner-europa-list-server@matronics.com] On Behalf Of Kingsley Hurst Sent: 27 June 2011 10:53 Subject: Europa-List: Another Propeller Question Is there anybody out there who has an NSI VP propeller with a constant speed controller of any sort? OR does anybody know what sort of CS controller would work on an NSI VP prop? Any comments most welcome. Thanks Kingsley in Oz. -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. ________________________________ Message 7 _____________________________________ Time: 04:02:22 AM PST US Subject: Europa-List: Europa XS monowheel 3D dxf file From: "smartieb" Does anyone out there have a 3D dxf file of a Europa XS monowheel? kit #561 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=344213#344213 ________________________________ Message 8 _____________________________________ Time: 04:04:09 AM PST US Subject: Europa-List: ULPower 260i in Europa From: "smartieb" I have purchased a UL260i and intend fitting to my Europa XS monowheel. Has any one had any experience and lessons learnt that they may care to share? Martin, kit #561 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=344214#344214 ________________________________ Message 9 _____________________________________ Time: 04:37:39 AM PST US From: Jos Okhuijsen Subject: Re: Europa-List: Woodcomp after Sales Service David, good friend, Thanks for your honest explanation of your bias towards Woodcomp. Your position, as their unpaid salesman must be awkward, and it must be very difficult to change your position. I on my turn have to admit that it has taken a long time to recover mentally and be able to reason clearly and stronly about the accident. Your next quote takes us to the cultprit of our difference of interpretation of the facts. "and it was apparent that the blades were close to zero pitch, so that regardless of how they got there it would be safe to say that a similar accident could not happen with an SR3000 that does not have the reverse option (which is not accepted by the LAA following your accident), as the standard props have not only electronic stops at the fine limits but also mechanical ones. " According to woodcomp, invited by the inspector, the blades were at a flyable pitch. Remembering the lack of thrust, and the overrevving, they must have been at a positive angle, NOT REVERSE, but with a pitch not enough to stay airborne. Why stopped the motor at that blade position and not later or sooner? Because, at the same moment the microswitch should cut in, it burned with a short circuit to ground, defying it's purpose and allowing the motor to run further. Next, adding throttle, the controller jumped in, reversing the polarity of the motor. The voltage now came direct, not anymore over the motor, on the microswitch and the breaker popped. Blaming the accident on the reversbility of the prop, thus assuming that a mechanical endstop makes it impossible for the prop to turn too fine to fly is mute as long nobody ever has checked that mechanical endstop. Sofar i have not heard of anybody who has checked this mechanical endstop on the non-reversable prop. Unless somebody, preferrably you, shorts or otherwise disables the end switches, and runs the motor till it jams, relying on the mechanical stop is not very wise to say the least. It would be also interesting to know if the gears would survive such a try. Has the LAA approved the feathering version? There is no mechanical endstop on the course side. Even more people will be relying on non reliable microswitches. I think it was Mark of Smartavionics who told be about Woodcomp banning its product. Mark, correct me if i am wrong. Next one: "The microswitches have changed over the years largely to improve their mechanical security but whether they are waterproof or not seems a bit irrelevant. I have flown through prolonged rain and found no problems, and you would expect that any water finding its way into a structure rotating at 2000+ rpm would very rapidly find its way out again. If you had parked the plane under a waterfall and the spinner was full of water before start up you might expect to notice problems when you switched on and went though the recommended pitch change check. " I read that as "there have been problems with the microswitches over the years". I challenge you to find any application were microswitches are used in open air. None are to be found in cars for example. As for flying in rain, and the behavior of water and air on a spinning service, have a look at any centrifugal pump. The backplate of the spinner, where the switches are and the big end opening in the cowl form such a pump. The rotating plate sheds water and air from it's side and sucks more in..... As for the pitch range check: The only thing you do is check that at that moment things are ok. It does not improve the quality of these switches. Apart from that everybody will hopefully understand the importance of using weatherproof components in weather. There are classes for humidity for electrical components and appliances. Those microswitches are manufactured for dry room use. And, let's not forget, they are heavily underrated in current as well. Proper switches for the application would physically never fit on that backplate. I hope the LAA will review its approval. I don't quite understand how this item passed in the first place. Regards, Jos 27.6.2011 12:12, David Joyce kirjoitti: > > > Jos, I count you as a good friend but have to dispute many of your > statements. I also will state that I am no expert, but nevertheless am > a very interested amateur prepared to go to great lengths to get to > the bottom of something that affects my safety, ( and having said that > Tim did spend a lot of years as a radar/ electronics technician in > the RAF). I have on the other hand been a sort of unofficial (but > unpaid I hasten to add) Woodcomp agent in the UK having brought (and > bought) the first Woodcomp prop into the UK and then pursued the very > lengthy process of getting it fully accepted by the PFA. > As you know I was there at the accident, with the same plane > and the same controller and the same SR3000 (albeit without the > reverse option). I flew back to try to help you and subsequently > examined the wreckage and spent some time helping the Austrian AAIB > man. As the accident happened flying out of the Rotax Factory Flyin > it's not surprising that they were quickly able to help. Secondly > since Mark Burton, owner of Smart Avionics,was flying with us he was > quick to talk to the investigator. I may say that I gave the > investigator my copies of the Smart Avionics controller and SR3000 > handbooks and allowed him to look at the complete workings of my set > up which was the official factory set up of an SR3000 without the > reverse option that you had and without the non Woodcomp/personal > simplifications to the wiring system that you had incorporated into > the circuitry. There wasn't too much left of the plane after the fire > but the prop hub was there and it was apparent that the blades were > close to zero pitch, so that regardless of how they got there it would > be safe to say that a similar accident could not happen with an SR3000 > that does not have the reverse option (which is not accepted by the > LAA following your accident), as the standard props have not only > electronic stops at the fine limits but also mechanical ones. > My understanding of the investigation was that no prime cause > could be positively identified, and if I do not misquote him I believe > this is also Mark Burton's view (who is also of course an electronics > professional.) > The microswitches have changed over the years largely to > improve their mechanical security but whether they are waterproof or > not seems a bit irrelevant. I have flown through prolonged rain and > found no problems, and you would expect that any water finding its way > into a structure rotating at 2000+ rpm would very rapidly find its way > out again. If you had parked the plane under a waterfall and the > spinner was full of water before start up you might expect to notice > problems when you switched on and went though the recommended pitch > change check. > You refer to the problem experienced by someone having some > teeth break on the gearing that determines the pitch angle of each > blade and this was promptly dealt with by Woodcomp replacing it both > on new models and retrospectively with a slightly heavier version of > the gears. Woodcomp certainly have no problem about the Smartavionics > controller which is the choice of the majority o f the substantial > number of UK Woodcomp owners. > Apart from your problem I have not come across problems that > were not of the failsafe variety, and feel that describing the prop as > a deathtrap is entirely unwarranted > Regards and best wishes David, G-XSDJ > You mention > > ----- Original Message ----- From: "josok-e" > To: > Sent: Sunday, June 26, 2011 11:46 PM > Subject: Re: Europa-List: Woodcomp after Sales Service > > >> Tim, >> >> I've sent the report to somebody who is German en fluently in English, >> on his offer to translate. This translation takes an incredible amount >> of time obviously. >> But, as a matter of fact, the investigator thanks me for diverting from >> my line of descent into an occupied office building to trees. The >> wreckage was badly burnt. He also reports that he had Woodcomp check the >> remains of the propellor, and that they stated that the blades "must >> have been at a flyable angle" Also there was no obvious fault with the >> engine. It has not been possible to determine what the cause of the >> accident was. You may doubt of course that i have summarized properly as >> well. >> Significant might be also that after the accident Rotax was the first to >> talk to me, smartavionics next, the factory was very interested also. >> But no question, no word from Woodcomp. >> >> I find it strange that you start an argument by telling us that you are >> not an expert. And reach a conclusion, which is false. I am an expert, >> electricity, electronics have been my profession and hobby. I know >> microswitches and diodes, and if i tell you they are grossly underrated >> and not up wet conditions, you can take my word for it. >> >> My only interest is to save your lives. If you don't want it, please let >> me know. >> >> So, let me explain how the prop ended in a non-flyable position, so >> simple that a non-expert can understand. I commanded via the controller >> to go finer. That makes the motor run the blades to fine. The motor runs >> then as long as the controller command it to go finer or the fine limit >> switch cuts the current. In this case, because the desired rpm was high, >> and i was climbing, the fine limit switch should cut in. But it didn't >> because it was burnt, and short circuited to earth. The controller >> reversed it voltage to increase pitch and we had a short circuit on the >> plus now. The circuitbreaker popped. The revs went to 6200, with no >> pull. Attempting to reset it booted the controller. Which proved it was >> still working, And after the boot it popped again, The accident >> conditions were there, low on altitude, low on speed. >> >> I find it amazing that people defend such a product. Everybody i spoke >> to privatly admids there have been problems with communication, with >> quality of parts, with forgotten or loose parts, splitting blades, >> whatever. Oh, of course, they will cut the blades in a banana form, or >> apple, or anything else you fancy as fast. Very flexible indeed. >> >> There is a good working product available, has been for years, factory >> choice, with only plusses but the price. >> Everybody makes a mistake, and i can admit it was my mistake to go on >> the cheap and settle for a Woodcomp. >> >> Regards, >> >> Jos >> >> >> >> 27.6.2011 0:25, houlihan kirjoitti: >>> Hi >>> Further to Jos's comments about his very serious accident I seem to >>> recall that the Austrian authorities planned to issue a report >>> regarding the possible cause. I may have missed it so can anyone let >>> me know what it contained, preferably in English. >>> Not being an expert in these things I find I have problems linking the >>> limit switch failure Jos talks about to the fact that for the >>> propeller to go to fully fine or even beyond fully fine to a beta >>> state requires the motor to be powered to drive it there. I am sure >>> there may be a mechanism that will make that happen but I cannot see >>> how it can do that just because a limit switch fails. >>> Also my understanding is that Woodcomp do not support the Smartavioncs >>> controller not surprising really as it is not their product and it is >>> in competition with them but " banning" it is beyond their remit. >>> Tim H >>> >>> On 26 June 2011 20:10, Jos Okhuijsen >> > wrote: >>> >>> Hi >>> >>> Sorry to remember you all that my Woodcomp prop nearly took my >>> life. >>> >>> I hate to repeat my words, but memories seem to be short. >>> The propeller i had was equipped with microswitches, which were >>> and ,after a change, still are not designed for outside use. >>> Nethertheless these switches are mounted on the backplate, open >>> for weather. >>> These switches are designed for AC 240 V, not for DC 12 V, and the >>> Amp rating is way below the current going through them. >>> The cross-over diodes are specified for less then half the current >>> drawn. >>> Even when activated only occasionally, it's a design flaw. >>> >>> Know to me are 3 incidents with short circuiting micro-switches, >>> both other pilots could land their plane without damage to their >>> plane or themselves. An incident with a loose gear, causing one >>> of the blades at a totally diffent angle then the others was >>> reported to me, and never made it to this forum. This seems to be >>> the happy family show, which i am now spoiling. :-( >>> It may well be that there are others, or people never fly in rain. >>> or are just very lucky. >>> >>> In my case, to the best of my knowledge, a microswitch short >>> circuited, taking the prop to a feather situation, shortly after >>> take-off. I had been flying in heavy rain for hours the other day. >>> >>> Unless thing have changed is Jyrki the only one who understands >>> English, if he's not available you are on your own. >>> >>> After my incident Woodcomp banned the Smart Avionic controller. >>> What that means is unclear to me. As far as i know, they never got >>> there own controller working decently. >>> >>> As for the figures, i've had trouble to keep up with a 912 with a >>> fixed prop and i was flying with a 914 and a Woodcomp 3000. The >>> only good figure seems to be the price. >>> >>> So in short: Save a few, risk your plane and life. >>> The choice is yours.... >>> >>> Regards, >>> >>> Jos Okhuijsen >>> (enjoying his second life :-) >>> >>> . 26.6.2011 19:16, Frans Veldman kirjoitti: >>> >>> --> Europa-List message posted by: Frans >>> Veldman> >>> >>> On 06/26/2011 04:02 PM, Paul McAllister wrote: >>> >>> I was very impressed with the results that David Joyce got >>> with his SR >>> 3000W propeller from Woodcomp. I would like to some >>> feedback from the >>> forum about there after sales experience from Woodcomp. >>> Please give me >>> the 'good, the bad and the ugly' >>> >>> I got excellent support and advice when I was ordering the >>> propeller >>> from Woodcomp directly and delivery was prompt. After that I >>> had no >>> reason to contact them again as the prop works flawlessly and >>> performs >>> better than expected. Had to service it at 50 hours and did >>> that at a >>> local Woodcomp dealer. Found that one spinner screw was >>> missing and got >>> a complete new spinner fastening set free of charge. Ordered >>> spare >>> brushes, but at the 100 hour check I discovered that the >>> brushes were >>> almost like new and it looks like it is going to take a long >>> while >>> before I have to replace them. >>> >>> Have now 100+ hours but have had no issues with the prop. >>> A few notes though: >>> 1) I'm using the controller from Smart Avionics which is very >>> configurable and able to match the prop exactly to the >>> engine/airframe >>> characteristics. >>> 2) I have a prop with feather capability (to anticipate a >>> potential >>> future use of the glider wings). The props with feather >>> capability have >>> a stronger and faster motor. Maybe this is the reason why the >>> Woodcomp >>> prop behaves like a hydraulic prop and reacts so fast that it >>> never >>> allows the RPM to surge off its target. >>> >>> Hope this helps, >>> >>> Frans >>> >>> >>> >>> >>> >>> >>> =================================== >>> target="_blank">http://www.matronics.com/Navigator?Europa-List >>> =================================== >>> http://forums.matronics.com >>> =================================== >>> le, List Admin. >>> ="_blank">http://www.matronics.com/contribution >>> =================================== >>> >>> >>> >>> >>> * >>> >>> >>> * >> >> > > ________________________________ Message 10 ____________________________________ Time: 04:58:03 AM PST US From: David Lewendon Subject: Re: Europa-List: Woodcomp after Sales Service Ooh now come on ladies put those handbags away! It's getting more and more like Prime Ministers questions. On 27 juin 11, at 13:34, Jos Okhuijsen wrote: > > David, good friend, > > Thanks for your honest explanation of your bias towards Woodcomp. > Your position, as their unpaid salesman must be awkward, and it must > be very difficult to change your position. > I on my turn have to admit that it has taken a long time to recover > mentally and be able to reason clearly and stronly about the accident. > Your next quote takes us to the cultprit of our difference of > interpretation of the facts. > > "and it was apparent that the blades were close to zero pitch, so > that regardless of how they got there it would be safe to say that a > similar accident could not happen with an SR3000 that does not have > the reverse option (which is not accepted by the LAA following your > accident), as the standard props have not only electronic stops at > the fine limits but also mechanical ones. " > > According to woodcomp, invited by the inspector, the blades were at > a flyable pitch. Remembering the lack of thrust, and the > overrevving, they must have been at a positive angle, NOT REVERSE, > but with a pitch not enough to stay airborne. > Why stopped the motor at that blade position and not later or sooner? > Because, at the same moment the microswitch should cut in, it burned > with a short circuit to ground, defying it's purpose and allowing > the motor to run further. Next, adding throttle, the controller > jumped in, reversing the polarity of the motor. The voltage now came > direct, not anymore over the motor, on the microswitch and the > breaker popped. > > Blaming the accident on the reversbility of the prop, thus assuming > that a mechanical endstop makes it impossible for the prop to turn > too fine to fly is mute as long nobody ever has checked that > mechanical endstop. > > Sofar i have not heard of anybody who has checked this mechanical > endstop on the non-reversable prop. Unless somebody, preferrably > you, shorts or otherwise disables the end switches, and runs the > motor till it jams, relying on the mechanical stop is not very wise > to say the least. It would be also interesting to know if the gears > would survive such a try. > > Has the LAA approved the feathering version? There is no mechanical > endstop on the course side. Even more people will be relying on non > reliable microswitches. > > I think it was Mark of Smartavionics who told be about Woodcomp > banning its product. Mark, correct me if i am wrong. > > Next one: > "The microswitches have changed over the years largely to improve > their mechanical security but whether they are waterproof or not > seems a bit irrelevant. I have flown through prolonged rain and > found no problems, and you would expect that any water finding its > way into a structure rotating at 2000+ rpm would very rapidly find > its way out again. If you had parked the plane under a waterfall and > the spinner was full of water before start up you might expect to > notice problems when you switched on and went though the recommended > pitch change check. " > > I read that as "there have been problems with the microswitches over > the years". I challenge you to find any application were > microswitches are used in open air. None are to be found in cars for > example. As for flying in rain, and the behavior of water and air on > a spinning service, have a look at any centrifugal pump. The > backplate of the spinner, where the switches are and the big end > opening in the cowl form such a pump. The rotating plate sheds water > and air from it's side and sucks more in..... As for the pitch > range check: The only thing you do is check that at that moment > things are ok. It does not improve the quality of these switches. > > Apart from that everybody will hopefully understand the importance > of using weatherproof components in weather. There are classes for > humidity for electrical components and appliances. Those > microswitches are manufactured for dry room use. And, let's not > forget, they are heavily underrated in current as well. Proper > switches for the application would physically never fit on that > backplate. > > I hope the LAA will review its approval. I don't quite understand > how this item passed in the first place. > > Regards, > > Jos > > > 27.6.2011 12:12, David Joyce kirjoitti: >> > >> >> Jos, I count you as a good friend but have to dispute many of your >> statements. I also will state that I am no expert, but nevertheless >> am a very interested amateur prepared to go to great lengths to get >> to the bottom of something that affects my safety, ( and having >> said that Tim did spend a lot of years as a radar/ electronics >> technician in the RAF). I have on the other hand been a sort of >> unofficial (but unpaid I hasten to add) Woodcomp agent in the UK >> having brought (and bought) the first Woodcomp prop into the UK and >> then pursued the very lengthy process of getting it fully accepted >> by the PFA. >> As you know I was there at the accident, with the same >> plane and the same controller and the same SR3000 (albeit without >> the reverse option). I flew back to try to help you and >> subsequently examined the wreckage and spent some time helping the >> Austrian AAIB man. As the accident happened flying out of the Rotax >> Factory Flyin it's not surprising that they were quickly able to >> help. Secondly since Mark Burton, owner of Smart Avionics,was >> flying with us he was quick to talk to the investigator. I may say >> that I gave the investigator my copies of the Smart Avionics >> controller and SR3000 handbooks and allowed him to look at the >> complete workings of my set up which was the official factory set >> up of an SR3000 without the reverse option that you had and without >> the non Woodcomp/personal simplifications to the wiring system that >> you had incorporated into the circuitry. There wasn't too much left >> of the plane after the fire but the prop hub was there and it was >> apparent that the blades were close to zero pitch, so that >> regardless of how they got there it would be safe to say that a >> similar accident could not happen with an SR3000 that does not have >> the reverse option (which is not accepted by the LAA following your >> accident), as the standard props have not only electronic stops at >> the fine limits but also mechanical ones. >> My understanding of the investigation was that no prime >> cause could be positively identified, and if I do not misquote him >> I believe this is also Mark Burton's view (who is also of course an >> electronics professional.) >> The microswitches have changed over the years largely to >> improve their mechanical security but whether they are waterproof >> or not seems a bit irrelevant. I have flown through prolonged rain >> and found no problems, and you would expect that any water finding >> its way into a structure rotating at 2000+ rpm would very rapidly >> find its way out again. If you had parked the plane under a >> waterfall and the spinner was full of water before start up you >> might expect to notice problems when you switched on and went >> though the recommended pitch change check. >> You refer to the problem experienced by someone having some >> teeth break on the gearing that determines the pitch angle of each >> blade and this was promptly dealt with by Woodcomp replacing it >> both on new models and retrospectively with a slightly heavier >> version of the gears. Woodcomp certainly have no problem about the >> Smartavionics controller which is the choice of the majority o f >> the substantial number of UK Woodcomp owners. >> Apart from your problem I have not come across problems >> that were not of the failsafe variety, and feel that describing the >> prop as a deathtrap is entirely unwarranted >> Regards and best wishes David, G-XSDJ >> You mention >> >> ----- Original Message ----- From: "josok-e" >> To: >> Sent: Sunday, June 26, 2011 11:46 PM >> Subject: Re: Europa-List: Woodcomp after Sales Service >> >> >>> Tim, >>> >>> I've sent the report to somebody who is German en fluently in >>> English, >>> on his offer to translate. This translation takes an incredible >>> amount >>> of time obviously. >>> But, as a matter of fact, the investigator thanks me for diverting >>> from >>> my line of descent into an occupied office building to trees. The >>> wreckage was badly burnt. He also reports that he had Woodcomp >>> check the >>> remains of the propellor, and that they stated that the blades "must >>> have been at a flyable angle" Also there was no obvious fault with >>> the >>> engine. It has not been possible to determine what the cause of the >>> accident was. You may doubt of course that i have summarized >>> properly as >>> well. >>> Significant might be also that after the accident Rotax was the >>> first to >>> talk to me, smartavionics next, the factory was very interested >>> also. >>> But no question, no word from Woodcomp. >>> >>> I find it strange that you start an argument by telling us that >>> you are >>> not an expert. And reach a conclusion, which is false. I am an >>> expert, >>> electricity, electronics have been my profession and hobby. I know >>> microswitches and diodes, and if i tell you they are grossly >>> underrated >>> and not up wet conditions, you can take my word for it. >>> >>> My only interest is to save your lives. If you don't want it, >>> please let >>> me know. >>> >>> So, let me explain how the prop ended in a non-flyable position, so >>> simple that a non-expert can understand. I commanded via the >>> controller >>> to go finer. That makes the motor run the blades to fine. The >>> motor runs >>> then as long as the controller command it to go finer or the fine >>> limit >>> switch cuts the current. In this case, because the desired rpm was >>> high, >>> and i was climbing, the fine limit switch should cut in. But it >>> didn't >>> because it was burnt, and short circuited to earth. The controller >>> reversed it voltage to increase pitch and we had a short circuit >>> on the >>> plus now. The circuitbreaker popped. The revs went to 6200, with no >>> pull. Attempting to reset it booted the controller. Which proved >>> it was >>> still working, And after the boot it popped again, The accident >>> conditions were there, low on altitude, low on speed. >>> >>> I find it amazing that people defend such a product. Everybody i >>> spoke >>> to privatly admids there have been problems with communication, with >>> quality of parts, with forgotten or loose parts, splitting blades, >>> whatever. Oh, of course, they will cut the blades in a banana >>> form, or >>> apple, or anything else you fancy as fast. Very flexible indeed. >>> >>> There is a good working product available, has been for years, >>> factory >>> choice, with only plusses but the price. >>> Everybody makes a mistake, and i can admit it was my mistake to go >>> on >>> the cheap and settle for a Woodcomp. >>> >>> Regards, >>> >>> Jos >>> >>> >>> >>> 27.6.2011 0:25, houlihan kirjoitti: >>>> Hi >>>> Further to Jos's comments about his very serious accident I seem to >>>> recall that the Austrian authorities planned to issue a report >>>> regarding the possible cause. I may have missed it so can anyone >>>> let >>>> me know what it contained, preferably in English. >>>> Not being an expert in these things I find I have problems >>>> linking the >>>> limit switch failure Jos talks about to the fact that for the >>>> propeller to go to fully fine or even beyond fully fine to a beta >>>> state requires the motor to be powered to drive it there. I am sure >>>> there may be a mechanism that will make that happen but I cannot >>>> see >>>> how it can do that just because a limit switch fails. >>>> Also my understanding is that Woodcomp do not support the >>>> Smartavioncs >>>> controller not surprising really as it is not their product and >>>> it is >>>> in competition with them but " banning" it is beyond their remit. >>>> Tim H >>>> >>>> On 26 June 2011 20:10, Jos Okhuijsen >>> > wrote: >>>> >>>> Hi >>>> >>>> Sorry to remember you all that my Woodcomp prop nearly took my >>>> life. >>>> >>>> I hate to repeat my words, but memories seem to be short. >>>> The propeller i had was equipped with microswitches, which were >>>> and ,after a change, still are not designed for outside use. >>>> Nethertheless these switches are mounted on the backplate, open >>>> for weather. >>>> These switches are designed for AC 240 V, not for DC 12 V, and >>>> the >>>> Amp rating is way below the current going through them. >>>> The cross-over diodes are specified for less then half the >>>> current >>>> drawn. >>>> Even when activated only occasionally, it's a design flaw. >>>> >>>> Know to me are 3 incidents with short circuiting micro-switches, >>>> both other pilots could land their plane without damage to their >>>> plane or themselves. An incident with a loose gear, causing one >>>> of the blades at a totally diffent angle then the others was >>>> reported to me, and never made it to this forum. This seems to >>>> be >>>> the happy family show, which i am now spoiling. :-( >>>> It may well be that there are others, or people never fly in >>>> rain. >>>> or are just very lucky. >>>> >>>> In my case, to the best of my knowledge, a microswitch short >>>> circuited, taking the prop to a feather situation, shortly after >>>> take-off. I had been flying in heavy rain for hours the other >>>> day. >>>> >>>> Unless thing have changed is Jyrki the only one who understands >>>> English, if he's not available you are on your own. >>>> >>>> After my incident Woodcomp banned the Smart Avionic controller. >>>> What that means is unclear to me. As far as i know, they never >>>> got >>>> there own controller working decently. >>>> >>>> As for the figures, i've had trouble to keep up with a 912 >>>> with a >>>> fixed prop and i was flying with a 914 and a Woodcomp 3000. The >>>> only good figure seems to be the price. >>>> >>>> So in short: Save a few, risk your plane and life. >>>> The choice is yours.... >>>> >>>> Regards, >>>> >>>> Jos Okhuijsen >>>> (enjoying his second life :-) >>>> >>>> . 26.6.2011 19:16, Frans Veldman kirjoitti: >>>> >>>> --> Europa-List message posted by: Frans >>>> Veldman>>> >> >>>> >>>> On 06/26/2011 04:02 PM, Paul McAllister wrote: >>>> >>>> I was very impressed with the results that David Joyce >>>> got >>>> with his SR >>>> 3000W propeller from Woodcomp. I would like to some >>>> feedback from the >>>> forum about there after sales experience from Woodcomp. >>>> Please give me >>>> the 'good, the bad and the ugly' >>>> >>>> I got excellent support and advice when I was ordering the >>>> propeller >>>> from Woodcomp directly and delivery was prompt. After that I >>>> had no >>>> reason to contact them again as the prop works flawlessly >>>> and >>>> performs >>>> better than expected. Had to service it at 50 hours and did >>>> that at a >>>> local Woodcomp dealer. Found that one spinner screw was >>>> missing and got >>>> a complete new spinner fastening set free of charge. >>>> Ordered spare >>>> brushes, but at the 100 hour check I discovered that the >>>> brushes were >>>> almost like new and it looks like it is going to take a >>>> long while >>>> before I have to replace them. >>>> >>>> Have now 100+ hours but have had no issues with the prop. >>>> A few notes though: >>>> 1) I'm using the controller from Smart Avionics which is >>>> very >>>> configurable and able to match the prop exactly to the >>>> engine/airframe >>>> characteristics. >>>> 2) I have a prop with feather capability (to anticipate a >>>> potential >>>> future use of the glider wings). The props with feather >>>> capability have >>>> a stronger and faster motor. Maybe this is the reason why >>>> the >>>> Woodcomp >>>> prop behaves like a hydraulic prop and reacts so fast that >>>> it >>>> never >>>> allows the RPM to surge off its target. >>>> >>>> Hope this helps, >>>> >>>> Frans >>>> >>>> >>>> >>>> >>>> >>>> >>>> =================================== >>>> target="_blank">http://www.matronics.com/Navigator?Europa-List >>>> =================================== >>>> http://forums.matronics.com >>>> =================================== >>>> le, List Admin. >>>> ="_blank">http://www.matronics.com/contribution >>>> =================================== >>>> >>>> >>>> >>>> >>>> * >>>> >>>> >>>> * >>> >>> >> >> >> >> >> > > ________________________________ Message 11 ____________________________________ Time: 05:13:20 AM PST US From: Guerner Remi Subject: Europa-List: Woodcomp after Sales Service Carl, I will not comment on Woodcomp as I am using an Airmaster. Note that the Airmaster Is accepted by the LAA in spite of having no coarse pitch physical (I mean mechanical) stop due to the feathering feature. Moreover the fine pitch mechanical stop (not adjustable) is at 2 degree blade tip angle which is useless as it is way too low to allow horizontal flight with the Europa. Remi Guerner <<<<<< In the UK the LAA won't allow a CS prop without physical limit stops for that very reason.>>>>>>>> ________________________________ Message 12 ____________________________________ Time: 06:12:36 AM PST US From: Fergus Kyle Subject: Europa-List: Woodcomp after sales service Jos, I am sorry for your accident and was careful to Google Earth your flight path - amazed at your survival in view of the circumstances. Naturally like most of us I can see why you would be angry at the outcome. Nevertheless, because I ahve a Woodcomp (as yet untested) I am interested in any and all discussions regarding it. I researched the company and am aware of its foundation in a healthy (if socialist) industry - at which they were fairly productive. Content with their family tree, I consulted a number of buyers, all of whom appeared content with the firm. I then visited Woodcomp north of Prague and was satisfied with the plant and its resources - modern, clean and efficient - four hours. In the process of installation, I managed to snap off one of the sintered brushes which transfer the energy to the rotating prop - and sent off a request for a replacement. It was not a design fault - I just had little room to manoeuvre in my spare bedroom and whacked it in passing. Jiri Holoubek didn't reply, so I sent a chaser. Apparently he was away and when he returned, I got an email requesting clarification. On receipt of my reply, along came two brushes in the mail - no charge. I am a licensed amateur builder but no electronic expert as you are apparently, but I assembled the prop and its controls without difficulty and ran the tests with no trouble. The faults you ascribe to the design were there when you assembled it, yet we got no complaint then in spite of what appears to an expert to be obvious failings. So my question is: Did you modify the system at all prior to the accident? Regards, Ferg ________________________________ Message 13 ____________________________________ Time: 06:54:45 AM PST US From: Jos Okhuijsen Subject: Re: Europa-List: Woodcomp after sales service Hi Ferg, No, the prop was as received -assembled- by woodcomp. No modifications. But you seem to miss the point Ferg, i am not complaining about their history, or their family tree. I have serious complaints about their inplantation of components not designed and not suitable for the job being asked from them. The result of that poor design caused my accident. If then folks, who are protecting their investment over their safety, are trying to convince others that business is as usual, i get really upset. Lack of knowledge is forgiveable. Not accepting facts or reducing their importance is not, especially if others are possibly getting involved. Regards, Jos 27.6.2011 16:09, Fergus Kyle kirjoitti: > > Jos, > > I am sorry for your accident and was carefulto Google Earth your > flight path--amazed at your survival in view of the circumstances. > Naturally like most of usI can see why you would be angry at the outcome. > > Nevertheless, because I ahve a Woodcomp (as yet untested)I am > interested in any and all discussions regarding it. I researched the > company and am aware of its foundation in a healthy (ifsocialist) > industry--at which they were fairly productive. Content with their > family tree, I consulted a number of buyers, all of whom appeared > content with the firm.I then visited Woodcomp north of Prague and was > satisfied with the plant and its resources--modern, clean and > efficient--four hours. > > In the process of installation, I managed to snap off one of the > sintered brushes whichtransfer the energyto the rotating prop--and > sent off a request for a replacement.It was not a design fault--I just > had little room to manoeuvre in my spare bedroom and whacked itin > passing.JiriHoloubekdidn't reply, so I sent a chaser. Apparently he > was away and when he returned,Igot an email requesting clarification. > On receipt of my reply, along came two brushes in the mail--no charge. > > I ama licensed amateur builder butno electronicexpertas you are > apparently,but I assembled the prop and its controls without > difficulty and ran the testswith no trouble. > > The faults you ascribe to the design were there when you assembled it, > yet we got no complaintthen in spite of what appears to an expert to > be obvious failings.So my question is: Did you modify the system at > all prior to the accident? > > Regards, Ferg > > * > > > * ________________________________ Message 14 ____________________________________ Time: 06:57:29 AM PST US Subject: Re: Europa-List: Europa XS monowheel 3D dxf file From: Paul McAllister Hi All, I would also be interested in *any* .dxf files that folks have. of the Europa . Thanks, Paul On Mon, Jun 27, 2011 at 5:56 AM, smartieb wrote: ________________________________ Message 15 ____________________________________ Time: 07:22:52 AM PST US Subject: Re: Europa-List: Woodcomp after Sales Service From: PHILLIPS I Hi Guys *Woodcomp SR3000 with reverse only* Last year flying from Prestwick to Lydd in rain and very gusty conditions I had my SR3000 motor burn out which took my pitch to fully fine and on to the stops, It was very sudden and certainly got my attention, but unlike Jos I had bee n in the cruise 120 kts and had time and speed to realise that I could keep the aircraft flying, Yes the Tachometer went into the red at first but as my airspeed dropped to 70 kts I could maintain height at 5500 rpm, I made a precautionary landing at headcorn, The complete Propeller was sent the my local Woodcomp agent, asking them to carefully Check the limit switches, it turned out the switches and diodes were fine but the motor Had burnt out, this was subsequently changed, I had done 300 hours before this incident And assumed because I always used auto when flying this had over worked th e pitch motor, especially in gusty wind conditions, since my propeller return to service I make a point of flying it manually if the conditions are poor , I have another 100 hours on the new motor and so far it is performing very well I also have the knowledge that a repeat of the problem would not mean an of f airfield landing, Mark at Smart avionics couldn=92t have been more helpful, while waiting for the new motor he heat soaked and bench tested my controller with not faults found, With a offer of a complete replacement unit if I wasn=92t happy, My original controller is still working flawlessly and I have a 100% confidence In its construction and software, Ivor G-IVER On 26 June 2011 15:02, Paul McAllister wrote: > Hi All, > > I was very impressed with the results that David Joyce got with his SR > 3000W propeller from Woodcomp. I would like to some feedback from the fo rum > about there after sales experience from Woodcomp. Please give me the 'go od, > the bad and the ugly' > > Thanks, Paul > > * > =========== =========== =========== =========== > * > > ________________________________ Message 16 ____________________________________ Time: 07:33:04 AM PST US Subject: Re: Europa-List: Woodcomp after Sales Service From: PHILLIPS I Amend the the first sentence to read *Woodcomp SR3000 with feather only,* fast finger freddie to blame [?] regards Ivor G-IVER On 27 June 2011 15:19, PHILLIPS I wrote: > Hi Guys > > *Woodcomp SR3000 with reverse only* > > > Last year flying from Prestwick to Lydd in rain and very gusty conditions > > I had my SR3000 motor burn out which took my pitch to fully fine and on t o > the stops, > > It was very sudden and certainly got my attention, but unlike Jos I had > been in the cruise > > 120 kts and had time and speed to realise that I could keep the aircraft > flying, > > > Yes the Tachometer went into the red at first but as my airspeed dropped to > 70 kts > > I could maintain height at 5500 rpm, I made a precautionary landing at > headcorn, > > > The complete Propeller was sent the my local Woodcomp agent, asking them to > carefully > > Check the limit switches, it turned out the switches and diodes were fin e > but the motor > > Had burnt out, this was subsequently changed, I had done 300 hours before > this incident > > And assumed because I always used auto when flying this had over worked > the pitch motor, especially in gusty wind conditions, since my propeller > return to service I make a point of flying it manually if the conditions > are poor, > > > I have another 100 hours on the new motor and so far it is performing ver y > well > > I also have the knowledge that a repeat of the problem would not mean an > off airfield landing, > > > Mark at Smart avionics couldn=92t have been more helpful, while waiting f or > the new motor he heat soaked and bench tested my controller with not faul ts > found, > > With a offer of a complete replacement unit if I wasn=92t happy, > > > My original controller is still working flawlessly and I have a 100% > confidence > > In its construction and software, > > > Ivor > > G-IVER > > > On 26 June 2011 15:02, Paul McAllister wrote : > >> Hi All, >> >> I was very impressed with the results that David Joyce got with his SR >> 3000W propeller from Woodcomp. I would like to some feedback from the f orum >> about there after sales experience from Woodcomp. Please give me the 'g ood, >> the bad and the ugly' >> >> Thanks, Paul >> >> * >> =========== =========== =========== =========== >> * >> >> > ________________________________ Message 17 ____________________________________ Time: 07:38:34 AM PST US Subject: Europa-List: Re: Woodcomp after Sales Service From: "Mark Burton" Hi, I have nothing to say re the suitability of the microswitches/diodes used by Woodcomp in the SR3000. However, from what I know about the characteristics of the scimitar bladed SR3000 fitted with either the reversing or feathering options, I feel that they are unlikely to have been the cause of Jos' accident. Let's consider some facts: Fact #1 - Woodcomp specified that a 10A circuit breaker should be used with that propeller and I believe that's what was fitted to Jos's aircraft. Fact #2 - under heavy load (high engine power, pitch motor stalled or moving very slowly), the SR3000 pitch motor is capable of drawing more than 10A. Fact #3 - Jos's propeller had recently returned from the factory and (Jos, please correct me if I am wrong), had not been checked to see that the fine limit microswitches were correctly set so that the aircraft would be flyable with the pitch stuck on fully fine. Therefore, it's possible for the C/B to pop simply by applying enough load to the pitch motor. If it pops when the prop is fully fine, expect trouble. Regards, Mark PS - I informed the factory in 2007 that the scimitar bladed SR3000 required an excessive amount of current to go coarse . Nothing came of it. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=344245#344245 ________________________________ Message 18 ____________________________________ Time: 08:13:19 AM PST US From: "G-IANI" Subject: RE: Europa-List: Europa XS monowheel 3D dxf file Martin & Paul. Due to the developments that I have been involved with I have many 2D drawings of the Europa all in AutoCad (DWG) which I can easily provide as DXF (but then the files are much larger). These are for the monowheel, Trigear and taildragger and range from the general layout drawings to specific component details. Generally I have both inch and metric versions. Accuracy varies depending on the source, whether they have been converted to metric and whether specific dimensions have been checked because they were relevant to what I was working on. It is also worth noting that some drawings, such as the fuselage mould lines, I have never found and probably never existed in a CAD form. So it is not a simple question. I will contact Martin, off line, about the UL Power installation. Paul if you would let me know what you are looking for I may be able to help. Ian Rickard G-IANI XS Trigear, 300hours Europa Club Mods Specialist e-mail g-iani@ntlworld.com ________________________________ Message 19 ____________________________________ Time: 10:43:12 AM PST US From: "David Joyce" Subject: Re: Europa-List: Woodcomp after Sales Service Jos, I am not sure it is helpful to prolong this, but yes I have tested my mechanical stop It is strong enough to stop a runaway electric motor I guess 100hp more powerful than the fitted one and comes into action a degree or two past the usual position so still capable of producing reasonable thrust. (For those who want to try it is necessary to isolate the wires to the motor by unsoldering them.) The microswitch problem was as far as I am aware simply mine. It was reported to LAA and to Woodcomp and indeed to you and the europa list, and no other such incidents had (or have since as far as I am aware)been reported. The side wall of the microswitch parted company because of a strange design and this could allow failure of the switch. Newer versions have the side wall integral with the entire structure. I have nothing to add to my views on the rain worthiness or the general reliability of the design. Regards, David ----- Original Message ----- From: "Jos Okhuijsen" Sent: Monday, June 27, 2011 12:34 PM Subject: Re: Europa-List: Woodcomp after Sales Service > > David, good friend, > > Thanks for your honest explanation of your bias towards Woodcomp. Your > position, as their unpaid salesman must be awkward, and it must be very > difficult to change your position. > I on my turn have to admit that it has taken a long time to recover > mentally and be able to reason clearly and stronly about the accident. > Your next quote takes us to the cultprit of our difference of > interpretation of the facts. > > "and it was apparent that the blades were close to zero pitch, so that > regardless of how they got there it would be safe to say that a similar > accident could not happen with an SR3000 that does not have the reverse > option (which is not accepted by the LAA following your accident), as the > standard props have not only electronic stops at the fine limits but also > mechanical ones. " > > According to woodcomp, invited by the inspector, the blades were at a > flyable pitch. Remembering the lack of thrust, and the overrevving, they > must have been at a positive angle, NOT REVERSE, but with a pitch not > enough to stay airborne. > Why stopped the motor at that blade position and not later or sooner? > Because, at the same moment the microswitch should cut in, it burned with > a short circuit to ground, defying it's purpose and allowing the motor to > run further. Next, adding throttle, the controller jumped in, reversing > the polarity of the motor. The voltage now came direct, not anymore over > the motor, on the microswitch and the breaker popped. > > Blaming the accident on the reversbility of the prop, thus assuming that a > mechanical endstop makes it impossible for the prop to turn too fine to > fly is mute as long nobody ever has checked that mechanical endstop. > > Sofar i have not heard of anybody who has checked this mechanical endstop > on the non-reversable prop. Unless somebody, preferrably you, shorts or > otherwise disables the end switches, and runs the motor till it jams, > relying on the mechanical stop is not very wise to say the least. It would > be also interesting to know if the gears would survive such a try. > > Has the LAA approved the feathering version? There is no mechanical > endstop on the course side. Even more people will be relying on non > reliable microswitches. > > I think it was Mark of Smartavionics who told be about Woodcomp banning > its product. Mark, correct me if i am wrong. > > Next one: > "The microswitches have changed over the years largely to improve their > mechanical security but whether they are waterproof or not seems a bit > irrelevant. I have flown through prolonged rain and found no problems, and > you would expect that any water finding its way into a structure rotating > at 2000+ rpm would very rapidly find its way out again. If you had parked > the plane under a waterfall and the spinner was full of water before start > up you might expect to notice problems when you switched on and went > though the recommended pitch change check. " > > I read that as "there have been problems with the microswitches over the > years". I challenge you to find any application were microswitches are > used in open air. None are to be found in cars for example. As for flying > in rain, and the behavior of water and air on a spinning service, have a > look at any centrifugal pump. The backplate of the spinner, where the > switches are and the big end opening in the cowl form such a pump. The > rotating plate sheds water and air from it's side and sucks more in..... > As for the pitch range check: The only thing you do is check that at that > moment things are ok. It does not improve the quality of these switches. > > Apart from that everybody will hopefully understand the importance of > using weatherproof components in weather. There are classes for humidity > for electrical components and appliances. Those microswitches are > manufactured for dry room use. And, let's not forget, they are heavily > underrated in current as well. Proper switches for the application would > physically never fit on that backplate. > > I hope the LAA will review its approval. I don't quite understand how this > item passed in the first place. > > Regards, > > Jos > > > 27.6.2011 12:12, David Joyce kirjoitti: >> >> >> Jos, I count you as a good friend but have to dispute many of your >> statements. I also will state that I am no expert, but nevertheless am a >> very interested amateur prepared to go to great lengths to get to the >> bottom of something that affects my safety, ( and having said that Tim >> did spend a lot of years as a radar/ electronics technician in the RAF). >> I have on the other hand been a sort of unofficial (but unpaid I hasten >> to add) Woodcomp agent in the UK having brought (and bought) the first >> Woodcomp prop into the UK and then pursued the very lengthy process of >> getting it fully accepted by the PFA. >> As you know I was there at the accident, with the same plane >> and the same controller and the same SR3000 (albeit without the reverse >> option). I flew back to try to help you and subsequently examined the >> wreckage and spent some time helping the Austrian AAIB man. As the >> accident happened flying out of the Rotax Factory Flyin it's not >> surprising that they were quickly able to help. Secondly since Mark >> Burton, owner of Smart Avionics,was flying with us he was quick to talk >> to the investigator. I may say that I gave the investigator my copies of >> the Smart Avionics controller and SR3000 handbooks and allowed him to >> look at the complete workings of my set up which was the official factory >> set up of an SR3000 without the reverse option that you had and without >> the non Woodcomp/personal simplifications to the wiring system that you >> had incorporated into the circuitry. There wasn't too much left of the >> plane after the fire but the prop hub was there and it was apparent that >> the blades were close to zero pitch, so that regardless of how they got >> there it would be safe to say that a similar accident could not happen >> with an SR3000 that does not have the reverse option (which is not >> accepted by the LAA following your accident), as the standard props have >> not only electronic stops at the fine limits but also mechanical ones. >> My understanding of the investigation was that no prime cause >> could be positively identified, and if I do not misquote him I believe >> this is also Mark Burton's view (who is also of course an electronics >> professional.) >> The microswitches have changed over the years largely to improve >> their mechanical security but whether they are waterproof or not seems a >> bit irrelevant. I have flown through prolonged rain and found no >> problems, and you would expect that any water finding its way into a >> structure rotating at 2000+ rpm would very rapidly find its way out >> again. If you had parked the plane under a waterfall and the spinner was >> full of water before start up you might expect to notice problems when >> you switched on and went though the recommended pitch change check. >> You refer to the problem experienced by someone having some >> teeth break on the gearing that determines the pitch angle of each blade >> and this was promptly dealt with by Woodcomp replacing it both on new >> models and retrospectively with a slightly heavier version of the gears. >> Woodcomp certainly have no problem about the Smartavionics controller >> which is the choice of the majority o f the substantial number of UK >> Woodcomp owners. >> Apart from your problem I have not come across problems that >> were not of the failsafe variety, and feel that describing the prop as a >> deathtrap is entirely unwarranted >> Regards and best wishes David, G-XSDJ >> You mention >> >> ----- Original Message ----- From: "josok-e" >> To: >> Sent: Sunday, June 26, 2011 11:46 PM >> Subject: Re: Europa-List: Woodcomp after Sales Service >> >> >>> Tim, >>> >>> I've sent the report to somebody who is German en fluently in English, >>> on his offer to translate. This translation takes an incredible amount >>> of time obviously. >>> But, as a matter of fact, the investigator thanks me for diverting from >>> my line of descent into an occupied office building to trees. The >>> wreckage was badly burnt. He also reports that he had Woodcomp check the >>> remains of the propellor, and that they stated that the blades "must >>> have been at a flyable angle" Also there was no obvious fault with the >>> engine. It has not been possible to determine what the cause of the >>> accident was. You may doubt of course that i have summarized properly as >>> well. >>> Significant might be also that after the accident Rotax was the first to >>> talk to me, smartavionics next, the factory was very interested also. >>> But no question, no word from Woodcomp. >>> >>> I find it strange that you start an argument by telling us that you are >>> not an expert. And reach a conclusion, which is false. I am an expert, >>> electricity, electronics have been my profession and hobby. I know >>> microswitches and diodes, and if i tell you they are grossly underrated >>> and not up wet conditions, you can take my word for it. >>> >>> My only interest is to save your lives. If you don't want it, please let >>> me know. >>> >>> So, let me explain how the prop ended in a non-flyable position, so >>> simple that a non-expert can understand. I commanded via the controller >>> to go finer. That makes the motor run the blades to fine. The motor runs >>> then as long as the controller command it to go finer or the fine limit >>> switch cuts the current. In this case, because the desired rpm was high, >>> and i was climbing, the fine limit switch should cut in. But it didn't >>> because it was burnt, and short circuited to earth. The controller >>> reversed it voltage to increase pitch and we had a short circuit on the >>> plus now. The circuitbreaker popped. The revs went to 6200, with no >>> pull. Attempting to reset it booted the controller. Which proved it was >>> still working, And after the boot it popped again, The accident >>> conditions were there, low on altitude, low on speed. >>> >>> I find it amazing that people defend such a product. Everybody i spoke >>> to privatly admids there have been problems with communication, with >>> quality of parts, with forgotten or loose parts, splitting blades, >>> whatever. Oh, of course, they will cut the blades in a banana form, or >>> apple, or anything else you fancy as fast. Very flexible indeed. >>> >>> There is a good working product available, has been for years, factory >>> choice, with only plusses but the price. >>> Everybody makes a mistake, and i can admit it was my mistake to go on >>> the cheap and settle for a Woodcomp. >>> >>> Regards, >>> >>> Jos >>> >>> >>> >>> 27.6.2011 0:25, houlihan kirjoitti: >>>> Hi >>>> Further to Jos's comments about his very serious accident I seem to >>>> recall that the Austrian authorities planned to issue a report >>>> regarding the possible cause. I may have missed it so can anyone let >>>> me know what it contained, preferably in English. >>>> Not being an expert in these things I find I have problems linking the >>>> limit switch failure Jos talks about to the fact that for the >>>> propeller to go to fully fine or even beyond fully fine to a beta >>>> state requires the motor to be powered to drive it there. I am sure >>>> there may be a mechanism that will make that happen but I cannot see >>>> how it can do that just because a limit switch fails. >>>> Also my understanding is that Woodcomp do not support the Smartavioncs >>>> controller not surprising really as it is not their product and it is >>>> in competition with them but " banning" it is beyond their remit. >>>> Tim H >>>> >>>> On 26 June 2011 20:10, Jos Okhuijsen >>> > wrote: >>>> >>>> Hi >>>> >>>> Sorry to remember you all that my Woodcomp prop nearly took my >>>> life. >>>> >>>> I hate to repeat my words, but memories seem to be short. >>>> The propeller i had was equipped with microswitches, which were >>>> and ,after a change, still are not designed for outside use. >>>> Nethertheless these switches are mounted on the backplate, open >>>> for weather. >>>> These switches are designed for AC 240 V, not for DC 12 V, and the >>>> Amp rating is way below the current going through them. >>>> The cross-over diodes are specified for less then half the current >>>> drawn. >>>> Even when activated only occasionally, it's a design flaw. >>>> >>>> Know to me are 3 incidents with short circuiting micro-switches, >>>> both other pilots could land their plane without damage to their >>>> plane or themselves. An incident with a loose gear, causing one >>>> of the blades at a totally diffent angle then the others was >>>> reported to me, and never made it to this forum. This seems to be >>>> the happy family show, which i am now spoiling. :-( >>>> It may well be that there are others, or people never fly in rain. >>>> or are just very lucky. >>>> >>>> In my case, to the best of my knowledge, a microswitch short >>>> circuited, taking the prop to a feather situation, shortly after >>>> take-off. I had been flying in heavy rain for hours the other day. >>>> >>>> Unless thing have changed is Jyrki the only one who understands >>>> English, if he's not available you are on your own. >>>> >>>> After my incident Woodcomp banned the Smart Avionic controller. >>>> What that means is unclear to me. As far as i know, they never got >>>> there own controller working decently. >>>> >>>> As for the figures, i've had trouble to keep up with a 912 with a >>>> fixed prop and i was flying with a 914 and a Woodcomp 3000. The >>>> only good figure seems to be the price. >>>> >>>> So in short: Save a few, risk your plane and life. >>>> The choice is yours.... >>>> >>>> Regards, >>>> >>>> Jos Okhuijsen >>>> (enjoying his second life :-) >>>> >>>> . 26.6.2011 19:16, Frans Veldman kirjoitti: >>>> >>>> --> Europa-List message posted by: Frans >>>> Veldman> >>>> >>>> On 06/26/2011 04:02 PM, Paul McAllister wrote: >>>> >>>> I was very impressed with the results that David Joyce got >>>> with his SR >>>> 3000W propeller from Woodcomp. I would like to some >>>> feedback from the >>>> forum about there after sales experience from Woodcomp. >>>> Please give me >>>> the 'good, the bad and the ugly' >>>> >>>> I got excellent support and advice when I was ordering the >>>> propeller >>>> from Woodcomp directly and delivery was prompt. After that I >>>> had no >>>> reason to contact them again as the prop works flawlessly and >>>> performs >>>> better than expected. Had to service it at 50 hours and did >>>> that at a >>>> local Woodcomp dealer. Found that one spinner screw was >>>> missing and got >>>> a complete new spinner fastening set free of charge. Ordered >>>> spare >>>> brushes, but at the 100 hour check I discovered that the >>>> brushes were >>>> almost like new and it looks like it is going to take a long >>>> while >>>> before I have to replace them. >>>> >>>> Have now 100+ hours but have had no issues with the prop. >>>> A few notes though: >>>> 1) I'm using the controller from Smart Avionics which is very >>>> configurable and able to match the prop exactly to the >>>> engine/airframe >>>> characteristics. >>>> 2) I have a prop with feather capability (to anticipate a >>>> potential >>>> future use of the glider wings). The props with feather >>>> capability have >>>> a stronger and faster motor. Maybe this is the reason why the >>>> Woodcomp >>>> prop behaves like a hydraulic prop and reacts so fast that it >>>> never >>>> allows the RPM to surge off its target. >>>> >>>> Hope this helps, >>>> >>>> Frans >>>> >>>> >>>> >>>> >>>> >>>> >>>> =================================== >>>> target="_blank">http://www.matronics.com/Navigator?Europa-List >>>> =================================== >>>> http://forums.matronics.com >>>> =================================== >>>> le, List Admin. >>>> ="_blank">http://www.matronics.com/contribution >>>> =================================== >>>> >>>> >>>> >>>> >>>> * >>>> >>>> >>>> * >>> >>> >> >> >> >> >> > > > ________________________________ Message 20 ____________________________________ Time: 12:23:37 PM PST US From: "Stephan Cassel" Subject: Re: Europa-List: Woodcomp after Sales Service Hi, I am very pleased with my SR2000 approaching 300 hours. I have one failure though. The company (Jiri) is very supportive. I ordered spare parts in order to repair the gear box. Within 3 days the parts arrived and the prop was back in service 3 days later. When or if I need to buy a new prop it will be a WoodComp. Wood and composite is great combination. Low vibration due different material=99s resonance and will save the engine in event of a prop strike. It is important to regular service. As it is for all variable pitch props. Regards Stephan LN-STE mono ________________________________ Message 21 ____________________________________ Time: 12:42:25 PM PST US From: Jos Okhuijsen Subject: Re: Europa-List: Re: Woodcomp after Sales Service Hi Mark, It's a pity Mark, that you have not checked the max DC specification of those microswitches. I am afraid they are even more underrated as their circuit breaker specification. I am also disappointed that you are not willing to comment on my "indoor use only" comment for these switches. I had tested the prop before when new, and did not test it after the repair. Maybe i was convinced that Woodcomp would have done a proper job. My mistake. Your scenario of the fatal flight could be possible, or not because your controller's pulse ratio would limit the max energy the motor would pull on full power. I think that Paul has now a good picture of the quality of the Woodcomp after sales service now. My god, you will need it. When ordering the prop from them do not forget to order spare microswitches, spare gears, a spare motor spare diodes and ask them if you may change their specification to a 20 A circuitbreaker. Add a full fine to coarse excercise to your checklist, and check before every flight that the microswitches are still in one piece. It's a pity you will have to unbolt the prop for that, but hey, you have saved a couple of thousand.:-) Regards, Jos Okhuijsen 27.6.2011 17:35, Mark Burton kirjoitti: > --> Europa-List message posted by: "Mark Burton" > > Hi, > > I have nothing to say re the suitability of the microswitches/diodes used by Woodcomp in the SR3000. However, from what I know about the characteristics of the scimitar bladed SR3000 fitted with either the reversing or feathering options, I feel that they are unlikely to have been the cause of Jos' accident. > > Let's consider some facts: > > Fact #1 - Woodcomp specified that a 10A circuit breaker should be used with that propeller and I believe that's what was fitted to Jos's aircraft. > > Fact #2 - under heavy load (high engine power, pitch motor stalled or moving very slowly), the SR3000 pitch motor is capable of drawing more than 10A. > > Fact #3 - Jos's propeller had recently returned from the factory and (Jos, please correct me if I am wrong), had not been checked to see that the fine limit microswitches were correctly set so that the aircraft would be flyable with the pitch stuck on fully fine. > > Therefore, it's possible for the C/B to pop simply by applying enough load to the pitch motor. If it pops when the prop is fully fine, expect trouble. > > Regards, > > Mark > > PS - I informed the factory in 2007 that the scimitar bladed SR3000 required an excessive amount of current to go coarse . Nothing came of it. > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=344245#344245 > > ________________________________ Message 22 ____________________________________ Time: 01:09:57 PM PST US From: nigel henry Subject: RE: Europa-List: Re: Woodcomp after Sales Service Well Guys=2C do we fit a plank of wood to the front of the R otax or are there other options I thought it was the prop of chose ? who's next and why do the manufactures not take notice of the pilots in the seat it all seems to work well tillll ..... and not enough safety margin Option s Guys |Options ? > Date: Mon=2C 27 Jun 2011 22:38:02 +0300 > From: josok-e@ukolo.fi > To: europa-list@matronics.com > Subject: Re: Europa-List: Re: Woodcomp after Sales Service > > > Hi Mark=2C > > It's a pity Mark=2C that you have not checked the max DC specification of > those microswitches. I am afraid they are even more underrated as their > circuit breaker specification. I am also disappointed that you are not > willing to comment on my "indoor use only" comment for these switches. > I had tested the prop before when new=2C and did not test it after the > repair. Maybe i was convinced that Woodcomp would have done a proper > job. My mistake. Your scenario of the fatal flight could be possible=2C o r > not because your controller's pulse ratio would limit the max energy the > motor would pull on full power. > > I think that Paul has now a good picture of the quality of the Woodcomp > after sales service now. My god=2C you will need it. When ordering the > prop from them do not forget to order spare microswitches=2C spare gears =2C > a spare motor spare diodes and ask them if you may change their > specification to a 20 A circuitbreaker. > Add a full fine to coarse excercise to your checklist=2C and check before > every flight that the microswitches are still in one piece. It's a pity > you will have to unbolt the prop for that=2C but hey=2C you have saved a > couple of thousand.:-) > > Regards=2C > > Jos Okhuijsen > > > > > 27.6.2011 17:35=2C Mark Burton kirjoitti: > > --> Europa-List message posted by: "Mark Burton" > > > > Hi=2C > > > > I have nothing to say re the suitability of the microswitches/diodes us ed by Woodcomp in the SR3000. However=2C from what I know about the charact eristics of the scimitar bladed SR3000 fitted with either the reversing or feathering options=2C I feel that they are unlikely to have been the cause of Jos' accident. > > > > Let's consider some facts: > > > > Fact #1 - Woodcomp specified that a 10A circuit breaker should be used with that propeller and I believe that's what was fitted to Jos's aircraft. > > > > Fact #2 - under heavy load (high engine power=2C pitch motor stalled or moving very slowly)=2C the SR3000 pitch motor is capable of drawing more t han 10A. > > > > Fact #3 - Jos's propeller had recently returned from the factory and (J os=2C please correct me if I am wrong)=2C had not been checked to see that the fine limit microswitches were correctly set so that the aircraft would be flyable with the pitch stuck on fully fine. > > > > Therefore=2C it's possible for the C/B to pop simply by applying enough load to the pitch motor. If it pops when the prop is fully fine=2C expect trouble. > > > > Regards=2C > > > > Mark > > > > PS - I informed the factory in 2007 that the scimitar bladed SR3000 req uired an excessive amount of current to go coarse . Nothing came of it. > > > > > > > > > > Read this topic online here: > > > > http://forums.matronics.com/viewtopic.php?p=344245#344245 > > > > > > > > > > > > > > > > > > > > > > =========== =========== =========== =========== > > > ________________________________ Message 23 ____________________________________ Time: 01:46:01 PM PST US Subject: Europa-List: Re: Woodcomp after Sales Service From: "kees de bussy" Hi all, I haven flown my Europa with the Woodcomp SR 3000 (with reverse option which is not wired) in many conditions, several times in heavy rain too. Up to now I have not met any problems (prop has approx 220 hrs.) To avoid problems as much as possible I always switch to manual before take-off and landing. This way never a signal will be given to change the pitch in the most critical phases of flight. I feel this way it makes it safer to operate this kind of prop (not only Woodcomp). Back on topic, I only had it checked once by a local dealer because of some play of the blades. Regards, Kees de Bussy Europa XS TG, PH-SBR Read this topic online here: http://forums.matronics.com/viewtopic.php?p=344288#344288 ________________________________ Message 24 ____________________________________ Time: 02:20:19 PM PST US From: Karl Heindl Subject: RE: Europa-List: Re: Woodcomp after Sales Service Kees=2C You are a very wise man. Forget about automatic pitch control below 1000 fe et. I have been doing the same after my own and Jos's experience. I will ne ver trust an electric prop again. But I wanted variable pitch and featherin g for gliding mode. But the original question from Paul was about support =2C not whether the make was any good. That seems to have improved=2C at le ast in Europe=2C but the problem I pointed out is still there: There is onl y one person to talk to. If he is not there and he goes on frequent sales t rips and there are long holidays=2C not to mention sick leave=2C then your support is one big zero.And I still say that the pitch motor is not up to t he job after two failures. An electric motor should never fail.They are off -the-shelf items from another company and were designed to power electric t ools for Bosch and Dremel etc. Karl > Subject: Europa-List: Re: Woodcomp after Sales Service > From: keesdebussy@hotmail.com > Date: Mon=2C 27 Jun 2011 13:42:52 -0700 > To: europa-list@matronics.com > om> > > Hi all=2C > > I haven flown my Europa with the Woodcomp SR 3000 (with reverse option wh ich is not wired) in many conditions=2C several times in heavy rain too. Up to now I have not met any problems (prop has approx 220 hrs.) To avoid pro blems as much as possible I always switch to manual before take-off and lan ding. This way never a signal will be given to change the pitch in the most critical phases of flight. I feel this way it makes it safer to operate th is kind of prop (not only Woodcomp). Back on topic=2C I only had it checked once by a local dealer because of some play of the blades. > > Regards=2C > > Kees de Bussy > Europa XS TG=2C PH-SBR > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=344288#344288 > > > > > > > =========== =========== =========== =========== > > > ________________________________ Message 25 ____________________________________ Time: 02:29:43 PM PST US From: glenn crowder Subject: RE: Europa-List: Another Propeller Question Sorry guys=2C I sent the one good controller I had to Jean Phillipe in Fran ce a while back. I still have the hub and digital prop pitch guage if anyone needs one. Glenn > CC: gcrowder2@hotmail.com > From: fklein@orcasonline.com > To: kingsnjan@westnet.com.au > Subject: Re: Europa-List: Another Propeller Question > Date: Mon=2C 27 Jun 2011 10:16:05 -0700 > > Hi Kingsley...Glenn Crowder may be the guy you're looking for... > > gcrowder2@hotmail.com > > Fred > com.au > > > > > > > Is there anybody out there who has an NSI VP propeller with a > > constant speed controller of any sort? > > > > OR > > > > does anybody know what sort of CS controller would work on an NSI VP > > prop? > > > > Any comments most welcome. > > > > Thanks > > Kingsley in Oz. ________________________________ Message 26 ____________________________________ Time: 02:42:44 PM PST US From: Frans Veldman Subject: Re: Europa-List: Re: Woodcomp after Sales Service On 06/27/2011 09:38 PM, Jos Okhuijsen wrote: > It's a pity Mark, that you have not checked the max DC specification of > those microswitches. The max DC specification of the switches is of little value. Max DC is mainly limited by the opening arc of the switches under load. In normal situations, the limit switches are never opened as the controller cuts the power long before the limit is reached. These switches are just sitting there all their life closed, waiting for a controller failure which is unlikely to happen anyway. In a previous statement you claimed that the run away was caused by failed micro switches. This is similar as claiming that you have had a trim servo run away because of a failing end stop in the trim servo. Such a claim would ignore the fact that the trim servo can only run away, with or without end stop, if something keeps feeding power to it after it reached the desired position. It would require a faulty cockpit switch or faulty pilot in addition. Similary: Your situation, even with shorted micro switches, could only occur if the controller or some other circuitry was failing at the same time: something was delivering power to the prop while it was already over the target RPM. Even then, this would never let the CB pop. There is only one controller and it can not give power to two opposite directions at the same time whatever failure mode you can devise. Someone asked whether you had modified the circuitry and you denied that. However in the archive (before the accident) I found a message where you wrote that you had the reverse circuitry modified to simplify the process of entering reverse (which is cumbersome in the original setup but maybe there was a reason for that), and if I recall it correctly a relay was used to switch the controller and feed power to the reverse ring of the prop at the same time. If this modified circuitry failed, it would explain fully what happened: While feeding unwanted power to the reverse ring of the prop the prop could reach 0 or negative angle because the reverse slip ring bypasses the limit switches (for logical reasons) AND the controller at the same time, and the CB would pop if the controller tried to reverse the engine polarity. The whole story of short circuited limit switches does not explain the problems in any way. I would be confident to operate the airplane with shorted limit switches AND shorted or busted diodes, as these items are never used while the controller is working properly. The function of the diodes is to allow the motor to run in the other direction once one of the limit switches opened (otherwise you could never recover from reaching the prop limit as the limit switch cuts ALL power to the prop). In normal operation the diodes are never used. Neither shorting them or opening them would affect the normal operation of the prop. Again, whether these diodes are fully up to specs wouldn't matter at all in normal situations as it is unlikely that any current will ever flow through them. Your situation further differs from standard configurations by using the scimitar blades, which are not pitch bias neutral under load but have strong aerodynamic resistance in one pitch direction. It could well be possible that changing the pitch in one way caused excessive current, while in the other direction the aerodynamic loads would try to changing the pitch even further, and maybe drive the blades over the limit causing the limit switches to open. And in such a situation it might be possible that the limit switches finally give up the ghost (but logically they would burn through and open up, making it impossible to change the pitch from there). Again, even in this scenario it would not lead to pitch run aways and popping CB's, but just to a prop which doesn't respond anymore to pitch change commands. Frans ________________________________ Message 27 ____________________________________ Time: 02:48:17 PM PST US Subject: Re: Europa-List: Re: Woodcomp after Sales Service From: Robert Borger Richard, If you want a constant speed prop, the prop of choice for many folks is the Airmaster propeller with their AC200F controller as recommended by Europa. It's not perfect but it does extremely well and they are always working to improve on it. They have their original 3 blade system with Warp Drive blades for either the 80/100 HP or 115+ HP engines as well as their new 2 blade system with blades from Sensenich. Their own controller works quite well. They have hub configurations available for most engines that folks stuff in the front of their Europas (Europii?) They have a long history of working with Europa and Europa builders. I find them most responsive and supportive of their products. Unfortunately, they are located in New Zealand which is on the other side of the earth, quite literally, from the U.K. and most of the remaining Europa population. Shipping back and forth is a bugger. Local reps, like Europa in the U.K. and Bud Yerly in the U.S.A. can help. In most cases their props seem a bit under-bladed for our application, so they might not wring out the last HP of efficiency but they used to push my Europa, back when it was still a monowheel, along at a solid 140 kts TAS @ 4.0 - 4.5 gph at about a 75% cruise power setting. I'm still about a week from flying the tri-gear conversion so I can't speak for it at this time. A final issue is the response time of the prop to a rapid throttle advance. It can be slower than desired producing a momentary exceed of the takeoff RPM. You can soon learn to compensate for this simply by not advancing the throttle as rapidly allowing the prop to keep up. They have an excellent web site at http://www.airmasterpropellers.com/Products.aspx with support and information on their AP332 and AP420 prop packages as well as hubs, blades, Controllers, spinners, extensions & hardware. Should you have any questions Martin, the owner, is the guy on the other end who will respond. I suggest you look into Airmaster before you commit to another prop manufacturer. Blue skies & tailwinds, Bob Borger Europa Kit #A221 N914XL, XS Tri-Gear, Intercooled 914, Airmaster C/S Prop http://www.europaowners.org/forums/gallery2.php?g2_itemId=60232 http://www.biplaneforumgallery.com/index.php?cat=10046 Europa Flying! 3705 Lynchburg Dr. Corinth, TX 76208 Home: 940-497-2123 Cel: 817-992-1117 On Jun 27, 2011, at 15:06, nigel henry wrote: > Well Guys, > do we fit a plank of wood to the front of the Rotax or are there other options I thought > it was the prop of chose ? who's next and why do the manufactures not take notice of the pilots in the seat > it all seems to work well tillll ..... and not enough safety margin Options Guys |Options ? ________________________________ Message 28 ____________________________________ Time: 04:12:30 PM PST US Subject: Europa-List: Re: Woodcomp after Sales Service From: "Mark Burton" OK, let's put our thinking caps on and ponder switches and diodes. We're only concerned here with the operation of the fine pitch limit switch and its associated diode (incidentally, the SR3000 has two fine limit switches and diodes in series so failures 1-4 described below have to occur to both switches/diodes, likely?) When the pitch is being reduced, the switch is carrying the current and the diode is reverse biased. The current level is not high and well within the breaking capability of the switch so it should open as expected and the pitch freezes on the fine limit (+ some overrun). Assuming that the switch has operated as it should, the pitch will now be fully fine. When the controller next commands the pitch to go coarse, the switch is already open so the diode will have to carry the current. That current can be large as it's basically the pitch motor stall current (initially around 25-30A, falling quickly as the motor spins up). Now the diode is only rated for 5A continuous current but it has a good pulse capability (check the data sheet) so it probably won't fail (we will talk about what happens if the diode fails next) - assuming the diode did not fail and the pitch motor is actually moving, the switch will close shortly afterwards. Exactly how much current will flow through the switch is difficult to predict because we don't know how much the motor has spun up so it could be quite a lot - mind you, there's only around 1V across the switch (the diode drop) so I should think the switch could hack it OK (perhaps with a reduced life). Now, let's consider some failure modes: 1 - the diode fails open circuit - in this case, when the switch opens as the pitch goes fully fine the pitch will freeze at that point (+ some overrun) and when the controller tries to coarsen the pitch nothing will happen because the switch is open and the diode is open too. Therefore, the end result will be the prop will be stuck in fully fine. But, this would not cause the C/B to pop. 2 - the diode fails short circuit - in this case when the switch opens as the prop reaches fully fine, the pitch motor keeps going and will drive the pitch all the way to reverse position (and the reverse switch would operate). If the controller subsequently tried to coarsen the pitch, it would succeed unless the diode decided the current was too much and died in which case the pitch would freeze. Now as it has been reported that the pitch of the prop was not in the reverse position this probably didn't happen. Again, the C/B would not blow. 3 - the switch fails open circuit - the pitch will not be able to reduce, only coarsen. C/B still intact. 4 - the switch fails short circuit - similar to 2 above, pitch could go to reverse. C/B still a happy bunny. 5 - there is a short circuit from one of the switches/diodes/wires to ground - now this is interesting: it could make the pitch go to the reverse position and then when the controller tried to move the pitch the other way it would blow the C/B. But as it's already been stated that the pitch was near the flyable region that makes this scenario unlikely but not impossible. So, from what we know about the accident, the only one of these failures that could have occurred is a short from one of the pitch motor drive wires to ground (either the wire itself or a switch/diode/motor failure). Is that likely, I don't know, but I reckon you could poor a bucket of water into a microswitch and it's not going to conduct substantial amounts of current to ground (sea water would conduct better). So, Jos, that's why I don't have much to say about the quality of the diodes and switches because apart from them physically flying apart and causing a short circuit to ground, I can't see how they could be responsible for the reported chain of events. Regards, Mark Read this topic online here: http://forums.matronics.com/viewtopic.php?p=344300#344300 ________________________________ Message 29 ____________________________________ Time: 04:15:57 PM PST US From: "JR Gowing" Subject: RE: Europa-List: Another Propeller Question What are you up to now? JR -----Original Message----- From: owner-europa-list-server@matronics.com [mailto:owner-europa-list-server@matronics.com] On Behalf Of Kingsley Hurst Sent: Monday, 27 June 2011 7:53 PM Subject: Europa-List: Another Propeller Question --> Is there anybody out there who has an NSI VP propeller with a constant speed controller of any sort? OR does anybody know what sort of CS controller would work on an NSI VP prop? Any comments most welcome. Thanks Kingsley in Oz. ----- No virus found in this message. Checked by AVG - www.avg.com ________________________________ Message 30 ____________________________________ Time: 04:27:27 PM PST US From: Jos Okhuijsen Subject: Re: Europa-List: Re: Woodcomp after Sales Service Hi Frans As usual, you haven't got a clue, and your arguments limp. In your explanation you could do away with a lot of things around your airplane, because if everyting goes well, you will not need them. Like fuses, circuitbrakers, a second fuel pump, not needed in normal circimstances. Maybe toys instead. In very normal life the controller will run until the limit switches are opened. Thats why they are there. If you don't understand that go and ask somebody, i am tired of explaning basic stuff to somebody who is not interested anyway. The rest of your answer is total rubbish, can't even bother. Is there somebody out there who can explain to this poor soul how it is supposed to work? Regards, Jos 28.6.2011 0:39, Frans Veldman kirjoitti: > --> Europa-List message posted by: Frans Veldman > > On 06/27/2011 09:38 PM, Jos Okhuijsen wrote: >> It's a pity Mark, that you have not checked the max DC specification of >> those microswitches. > The max DC specification of the switches is of little value. Max DC is > mainly limited by the opening arc of the switches under load. In normal > situations, the limit switches are never opened as the controller cuts > the power long before the limit is reached. These switches are just > sitting there all their life closed, waiting for a controller failure > which is unlikely to happen anyway. > > In a previous statement you claimed that the run away was caused by > failed micro switches. This is similar as claiming that you have had a > trim servo run away because of a failing end stop in the trim servo. > Such a claim would ignore the fact that the trim servo can only run > away, with or without end stop, if something keeps feeding power to it > after it reached the desired position. It would require a faulty cockpit > switch or faulty pilot in addition. Similary: Your situation, even with > shorted micro switches, could only occur if the controller or some other > circuitry was failing at the same time: something was delivering power > to the prop while it was already over the target RPM. Even then, this > would never let the CB pop. There is only one controller and it can not > give power to two opposite directions at the same time whatever failure > mode you can devise. > > Someone asked whether you had modified the circuitry and you denied > that. However in the archive (before the accident) I found a message > where you wrote that you had the reverse circuitry modified to simplify > the process of entering reverse (which is cumbersome in the original > setup but maybe there was a reason for that), and if I recall it > correctly a relay was used to switch the controller and feed power to > the reverse ring of the prop at the same time. > > If this modified circuitry failed, it would explain fully what happened: > While feeding unwanted power to the reverse ring of the prop the prop > could reach 0 or negative angle because the reverse slip ring bypasses > the limit switches (for logical reasons) AND the controller at the same > time, and the CB would pop if the controller tried to reverse the engine > polarity. > > The whole story of short circuited limit switches does not explain the > problems in any way. I would be confident to operate the airplane with > shorted limit switches AND shorted or busted diodes, as these items are > never used while the controller is working properly. > > The function of the diodes is to allow the motor to run in the other > direction once one of the limit switches opened (otherwise you could > never recover from reaching the prop limit as the limit switch cuts ALL > power to the prop). In normal operation the diodes are never used. > Neither shorting them or opening them would affect the normal operation > of the prop. Again, whether these diodes are fully up to specs wouldn't > matter at all in normal situations as it is unlikely that any current > will ever flow through them. > > Your situation further differs from standard configurations by using the > scimitar blades, which are not pitch bias neutral under load but have > strong aerodynamic resistance in one pitch direction. It could well be > possible that changing the pitch in one way caused excessive current, > while in the other direction the aerodynamic loads would try to changing > the pitch even further, and maybe drive the blades over the limit > causing the limit switches to open. And in such a situation it might be > possible that the limit switches finally give up the ghost (but > logically they would burn through and open up, making it impossible to > change the pitch from there). Again, even in this scenario it would not > lead to pitch run aways and popping CB's, but just to a prop which > doesn't respond anymore to pitch change commands. > > Frans > > ________________________________ Message 31 ____________________________________ Time: 05:13:11 PM PST US From: Jos Okhuijsen Subject: Re: Europa-List: Re: Woodcomp after Sales Service Hi Mark, Excellent work. And probably more understandable for the crowd then what i manage to explain. My guess is number 5, and i think i can make that plausible. I have been finding and replacing faulty microswitches in an industrial environment, and the cause of the failure was usually water ingress in the switches. What happens is that the water, which only has to be one drop, boils between the contacts in a flash. The metal vaporizes and forms a conductor on the insulation. The steam breaks the housing, with could then hang the contacts up the mounting. Very much like the microswith David describes. It sounds like you would need a lot of power for that, but don't forget, these are microswitches, it's all very light and feeble. An open contact could be 0.1 of a mil. I think what happened is that the controller run the prop fine. The fine limit microswitch(es) opened, exploded and shorted to ground. The controller reversed to increase pitch and the breaker popped. You don't mention Ivor's narrow escape with a broken motor, which looks a lot like mine, with the difference that he had speed and altitude. The investigator told me that the motor was loose in the spinner but he blames that to the impact. I still don't understand your willingsness to accept a 5 A diode, which has to endure regularly 15 A. It could work in a toy car, but is not acceptable in an airplane. You a talking about pulse load, In my book a pulse is microseconds, a reversing motor will take considerately more time. Does somebody have the typenumbers of the old and newer microswitches? From memory the AC to DC max current is about 5 to one, which would ask for 75 AC switches. I bet they are 6 A :-) Regards, Jos 28.6.2011 2:09, Mark Burton kirjoitti: > --> Europa-List message posted by: "Mark Burton" > > OK, let's put our thinking caps on and ponder switches and diodes. > > We're only concerned here with the operation of the fine pitch limit switch and its associated diode (incidentally, the SR3000 has two fine limit switches and diodes in series so failures 1-4 described below have to occur to both switches/diodes, likely?) > > When the pitch is being reduced, the switch is carrying the current and the diode is reverse biased. The current level is not high and well within the breaking capability of the switch so it should open as expected and the pitch freezes on the fine limit (+ some overrun). > > Assuming that the switch has operated as it should, the pitch will now be fully fine. When the controller next commands the pitch to go coarse, the switch is already open so the diode will have to carry the current. That current can be large as it's basically the pitch motor stall current (initially around 25-30A, falling quickly as the motor spins up). Now the diode is only rated for 5A continuous current but it has a good pulse capability (check the data sheet) so it probably won't fail (we will talk about what happens if the diode fails next) - assuming the diode did not fail and the pitch motor is actually moving, the switch will close shortly afterwards. Exactly how much current will flow through the switch is difficult to predict because we don't know how much the motor has spun up so it could be quite a lot - mind you, there's only around 1V across the switch (the diode drop) so I should think the switch could hack it OK (perhaps with a reduced life). > > Now, let's consider some failure modes: > > 1 - the diode fails open circuit - in this case, when the switch opens as the pitch goes fully fine the pitch will freeze at that point (+ some overrun) and when the controller tries to coarsen the pitch nothing will happen because the switch is open and the diode is open too. Therefore, the end result will be the prop will be stuck in fully fine. But, this would not cause the C/B to pop. > > 2 - the diode fails short circuit - in this case when the switch opens as the prop reaches fully fine, the pitch motor keeps going and will drive the pitch all the way to reverse position (and the reverse switch would operate). If the controller subsequently tried to coarsen the pitch, it would succeed unless the diode decided the current was too much and died in which case the pitch would freeze. Now as it has been reported that the pitch of the prop was not in the reverse position this probably didn't happen. Again, the C/B would not blow. > > 3 - the switch fails open circuit - the pitch will not be able to reduce, only coarsen. C/B still intact. > > 4 - the switch fails short circuit - similar to 2 above, pitch could go to reverse. C/B still a happy bunny. > > 5 - there is a short circuit from one of the switches/diodes/wires to ground - now this is interesting: it could make the pitch go to the reverse position and then when the controller tried to move the pitch the other way it would blow the C/B. But as it's already been stated that the pitch was near the flyable region that makes this scenario unlikely but not impossible. > > So, from what we know about the accident, the only one of these failures that could have occurred is a short from one of the pitch motor drive wires to ground (either the wire itself or a switch/diode/motor failure). Is that likely, I don't know, but I reckon you could poor a bucket of water into a microswitch and it's not going to conduct substantial amounts of current to ground (sea water would conduct better). > > So, Jos, that's why I don't have much to say about the quality of the diodes and switches because apart from them physically flying apart and causing a short circuit to ground, I can't see how they could be responsible for the reported chain of events. > > Regards, > > Mark > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=344300#344300 > > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message europa-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Europa-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/europa-list Browse Digests http://www.matronics.com/digest/europa-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.