---------------------------------------------------------- Zenith-List Digest Archive --- Total Messages Posted Thu 08/03/06: 25 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 01:07 AM - Composite Gear (Hunt Malcolm) 2. 01:47 AM - Re: Composite Gear (Hunt Malcolm) 3. 03:31 AM - Re: Engine Choices for Zodiac XL (Phil Maxson) 4. 04:12 AM - Re: Engine Choices for Zodiac XL () 5. 05:23 AM - Machine Shop (Rick R) 6. 05:55 AM - Re: Engine Choices for Zodiac XL (William Dominguez) 7. 07:31 AM - Re: 701 seat belt attach (doug kandle) 8. 07:44 AM - Re: 701 seat belt attach (N5SL) 9. 07:46 AM - Re: Polished Aluminum (Stanley Challgren) 10. 07:50 AM - Re: 701 seat belt attach (NYTerminat@aol.com) 11. 07:50 AM - 3D printers (Robert Schoenberger) 12. 08:10 AM - Re: 701 seat belt attach (doug kandle) 13. 08:19 AM - Re: 3D printers (John Marzulli) 14. 08:32 AM - Re: 3D printers (Bill Cardell) 15. 08:52 AM - Re: 3D/Skunk Wrks/etc (Zed Smith) 16. 09:03 AM - Re: Re: 3D/Skunk Wrks/etc () 17. 09:23 AM - Re: 701 seat belt attach (TYA2) 18. 09:27 AM - Re: 3D printers (Paul Mulwitz) 19. 09:30 AM - Please, no more 3D!! (Zed Smith) 20. 09:42 AM - Re: 3D printers (Tom and Bren Henderson) 21. 12:30 PM - Re: 701 seat belt attach (Al Young) 22. 01:24 PM - Seat belt attachment (George Swinford) 23. 01:27 PM - Belt attachment (Zed Smith) 24. 07:17 PM - Re: Machine Shop (Rick R) 25. 10:12 PM - Re: Engine for 601XL (Gary Gower) ________________________________ Message 1 _____________________________________ Time: 01:07:30 AM PST US From: "Hunt Malcolm" Subject: Zenith-List: Composite Gear Threat Friends On Monday I had all the steel components welded up and can now take stock of the landing gear weights. I have weighed the components, the two composite legs (supplied by CZAW but look the same as the ACS) weighed total of 5.13 kg with the steel gear chambers (6B11-5CZ) and the fuselage mounts (6B11-14CZ) weighing a further 2.72kg. So the grand total is 7.85kg or 17.31lb. The CZAW plans show purpose made steel axles similar to the Grove 5012, I would prefer to use the Grove Wheels set up but this would mean cutting away the composite which I'm not keen on doing, so will probably go with the purpose made CZAW axle units. The two axles would come out at about 2kg or 4.4lb total. There is some deepening of the gear channel 6B5-5 and its thickness goes from .032" to .040" but this would not give much extra weight. Sundry nuts bolts and washers not included in above as they will be very similar to aluminium gear fittings. Hope this of interest. Malcolm Hunt CH601XL Plans builder in England *************************************************************************** ************************************ The content of this email (and any attachment) is confidential. It may also be legally privileged or otherwise protected from disclosure. This email should not be used by anyone who is not an original intended rec ipient, nor may it be copied or disclosed to anyone who is not an original intended recipient. If you have received this email by mist ake please notify us by emailing the sender, and then delete the email and any copies from your system. Liability cannot be accepted for statements made which are clearly the send ers own and not made on behalf of Network Rail. *************************************************************************** ************************************ ________________________________ Message 2 _____________________________________ Time: 01:47:52 AM PST US From: "Hunt Malcolm" Subject: RE: Zenith-List: Composite Gear David Wright has corrected me; I meant the salutation to read Thread Friends. No reflection on inner thoughts!!! Best wishes Malcolm ________________________________ [mailto:owner-zenith-list-server@matronics.com] On Behalf Of Hunt Malcolm Sent: 03 August 2006 09:03 Threat Friends On Monday I had all the steel components welded up and can now take stock of the landing gear weights. I have weighed the components, the two composite legs (supplied by CZAW but look the same as the ACS) weighed total of 5.13 kg with the steel gear chambers (6B11-5CZ) and the fuselage mounts (6B11-14CZ) weighing a further 2.72kg. So the grand total is 7.85kg or 17.31lb. The CZAW plans show purpose made steel axles similar to the Grove 5012, I would prefer to use the Grove Wheels set up but this would mean cutting away the composite which I'm not keen on doing, so will probably go with the purpose made CZAW axle units. The two axles would come out at about 2kg or 4.4lb total. There is some deepening of the gear channel 6B5-5 and its thickness goes from .032" to .040" but this would not give much extra weight. Sundry nuts bolts and washers not included in above as they will be very similar to aluminium gear fittings. Hope this of interest. Malcolm Hunt CH601XL Plans builder in England ************************************************************************ *************************************** The content of this email (and any attachment) is confidential. It may also be legally privileged or otherwise protected from disclosure. This email should not be used by anyone who is not an original intended recipient, nor may it be copied or disclosed to anyone who is not an original intended recipient. If you have received this email by mistake please notify us by emailing the sender, and then delete the email and any copies from your system. Liability cannot be accepted for statements made which are clearly the senders own and not made on behalf of Network Rail. ************************************************************************ *************************************** Your attention is drawn to the fact that this email originated from a source external to Network Rail. *************************************************************************** ************************************ The content of this email (and any attachment) is confidential. It may also be legally privileged or otherwise protected from disclosure. This email should not be used by anyone who is not an original intended rec ipient, nor may it be copied or disclosed to anyone who is not an original intended recipient. If you have received this email by mist ake please notify us by emailing the sender, and then delete the email and any copies from your system. Liability cannot be accepted for statements made which are clearly the send ers own and not made on behalf of Network Rail. *************************************************************************** ************************************ ________________________________ Message 3 _____________________________________ Time: 03:31:29 AM PST US From: "Phil Maxson" Subject: RE: Zenith-List: Engine Choices for Zodiac XL --> Zenith-List message posted by: "Phil Maxson" Tom, Well said! I agree. Phil Maxson 601XL/Corvair Northwest New Jersey Do Not Archive >From: "Tom Farin" >To: >Subject: Zenith-List: Engine Choices for Zodiac XL >Date: Wed, 2 Aug 2006 20:53:25 -0500 > >Folks, > >First let me compliment the posters on this subject for not trashing each >other's viewpoints and turning this discussion into a war. > <> ________________________________ Message 4 _____________________________________ Time: 04:12:59 AM PST US From: Subject: Re: Zenith-List: Engine Choices for Zodiac XL --> Zenith-List message posted by: Tom Nice Post, This covers my point of view. I think you have the correct approach. Gary Ray ----- Original Message ----- Sent: Wednesday, August 02, 2006 9:53 PM Folks, First let me compliment the posters on this subject for not trashing each other's viewpoints and turning this discussion into a war. ________________________________ Message 5 _____________________________________ Time: 05:23:31 AM PST US From: Rick R Subject: Zenith-List: Machine Shop Any Zenith listers with a machine shop? I need a chunk of metal. Will you contact me off line? thanks DO NOT ARCHIVE Rick Sharpsburg, GA. USA http://www.n701rr.com ________________________________ Message 6 _____________________________________ Time: 05:55:44 AM PST US From: William Dominguez Subject: Re: Zenith-List: Engine Choices for Zodiac XL --> Zenith-List message posted by: William Dominguez This is an excellent post, well said Tom. I enjoy the topics on engine selection so much that it doesnt bother me that much when it goes out of control. In my case, I already have a Corvair core and that is the path I would like to pursue. However, since Im still years away from hanging an engine into my airframe, I have the time in my favor and newer information will hopefully confirm my current choice or will lead me to look elsewhere. That why Im trying to get as much information about engines as possible and I really appreciate these threads. This is also what motivated me to start www.ea-report.com, to collect a good database of real life experiences about engine reliability and performance data that I will make available to the community. William Dominguez Plans built Zodiac 601XL Working on tail www.ea-report.com Do not archive --- Tom Farin wrote: > Folks, > > First let me compliment the posters on this subject > for not trashing each other's viewpoints and turning > this discussion into a war. > > I'm a new builder and thought I'd share my thoughts > on the subject. I'm working on the XL tail section > and have three Corvair core engines I'm in the > process of disassembling. But I also went up in the > Jabiru equipped factory XL at the Romeoville, IL > Sport Pilot fly in. And I just returned from > Oshkosh. > > I haven't seen this posted to the list although many > of you are aware of the fact the Zenith both had > both a Jabiru equipped XL and a Corvair equipped XL. > The Corvair equipped XL was WW's plane and he spent > a fair amount of time in the Zenith booth. > > I sat through two WW presentations and talked > extensively with William and Gus from the WW > operation and with the Zenith factory reps. One of > the factory reps (who I won't mention by name) told > me if he was to build an XL personally, he'd build > one with a Corvair engine. Do I consider any of > this to be a formal endorsement of Corvair power by > Zenith? No. But It does make me feel better about > the direction in which I am headed. > > One of the posters indicated he felt some folks > doing automotive conversions were doing so for the > wrong reasons. I'm not sure which auto conversions > he was discussing. And I'm not sure which reasons > were the "wrong reason". Here are the three most > common reasons I can think of for doing a Corvair > conversion. > > 1. Cost - there is no question an auto conversion > is going to be cheaper than a new Jabiru or Rotax. > It is highly probable that a Corvair conversion will > also be cheaper than a rebuild of an O-200. I'm > aware some are claiming an O-200 build can be done > for $4,000. I've been watching prices of O-200s on > eBay. Based on what I've seen, coming in > significantly under $12,000 for a rebuilt engine > (without starting with a core) would be an > accomplishment. > > 2. Education/Maintenance - There is no question in > my mind I will learn a whole lot more building an > engine myself than taking delivery of a new or > rebuilt engine in a crate. In turn, I'm going to be > in much better shape to do maintenance and repairs > myself including field repairs. > > 3. Satisfaction - Isn't this one of the reasons > many of us are building Zodiacs, either from kits or > from scratch? In fact, couldn't the same three > reasons be given for our decisions to build kits or > scratchbuild the airframe itself. > > Here are the reasons I've heard given for not doing > an auto conversion. I've added my reactions to the > arguments. > 1. Ignition system redundancy - Because much of the > WW conversion offers redundancy for almost the > entire ignition system, a large point is made of the > fact there are not two spark plugs per cylinder. An > inoperative spark plug is a big issue on a 4 > cylinder engine. It is much less so on a six. > There is at least one ducumented case of a Corvair > landing without any particular drama with one of the > spark plug totally out of the head. > > 2. Inappropriate Design for aviation - Most of the > discussion relating to corvairs relates to > crankshaft issues. Corvairs have been flying in > aircraft since the Corvair was introduced in 1960. > Only recently have crank issues surfaced, for the > most part on engines with increased horespower, or > extended cranks, and non-nitrided cranks. I've read > every piece of material on Corvair crank failures I > can lay my hands on. There is no history I can find > of crank failures on Corvairs with nitrided cranks > built to produce 100 hp without crank extensions. > The other problems I've heard aout with Corvair > powered Experimentals involve components that are > also found on aviation purposed engines that appear > to be subject to the same problems. > > 3. Parts availability in the field (Podunk, NE) and > field maintenance - This may be a valid point if > looking for parts or maintenance if the alternative > is a Continental or Lycoming engine. But I'd bet It > would be easier to come up with a Corvair part than > a Jabiru or Rotax part in a remote location. If > A&Es don't like to work on experimentals, would they > feel good about and be qualified to work on a Roitax > or Jabiru engine? I'm asking. I don't know the > answer. > > 4. Resale value - Given that only a few Corvair > powered XLs are flying, I'm not sure anyone knows > the answer to this question. There is a strong > Corvair community. And I've seen partially complete > WW Corvair conversions go on eBay for more than the > builder had in the engine. > > 5. Safety - Some have claimed that building an auto > conversion adds to the crash statistics. I suppose > that is likely to be a correct statement although > I've seen no statistics to support it. But couldn't > the same be said for scratch building or kit > building an airframe? Someone said they cringe > every time they read about a crash of an auto > conversion. I cringed when I read the FAA report > about the Zodiac whos wings folded up killing both > the flight instructor and the owner. My son really > cringed when he close up witnessed what a WW2 dive > bomber can do to a Vans RV on the taxiway at Oshkosh > last week. Let's face it. Flying is risky. > > So here's where I'm at. I'm building a Zodiac XL > knowing full well the risk is higher that I'll crash > with a plane I build myself than if I bought a > factory built airplane. The same is true of the > engine. I'm going to begin building a Corvair > engine and a Zodiac XL. Actually I'm about half way > through the XL's tail. Along the way I'm going to > learn a hell of a lot about building both planes and > engines. As I proceed I'm going to keep asking > myself two questions. Do you feel good enough about > the job you are doing in building this airframe to > bet your life on your skills? Do you feel good > enough about the the job you are doing building this > engine and what else you have learned about its > safety to bet your life on your skills and > knowledge? > > In a few years from now when both are nearly > complete I'll have to make a decision. It will come > down to three choices. > 1. Don't fly the plane or the engine. I'll have > learned a hell of a lot about both and I'm likely to > recover most of my investment. If I don't get it > all back, I'll consider the difference as an > investment in my education and an enjoyable hobby. > Probably a whole lot cheaper than owning a boat or > playing golf. > > 2. Buy an aviation purposed engine and fly the > Zodiac. I'll either sell the Corvair engine for > close to what I have in it or drop it in a Corvair > automobile. And I'll be much better prepared to > maintain my aviation purposed engine. > > 3. Fly a Corvair powered Zodiac and take the risk. > But it will be a calculated risk. And in my mind > that's what Experimental aviation is all about. > > Thanks for listening. > > Tom Farin > > > > ________________________________ Message 7 _____________________________________ Time: 07:31:35 AM PST US From: "doug kandle" Subject: Zenith-List: Re: 701 seat belt attach --> Zenith-List message posted by: "doug kandle" I don't watch this thread all of the time and so I am not familiar with the incident with Jon. Could you say what basically happened or point me to the thread with that discussion. Thanks Read this topic online here: http://forums.matronics.com/viewtopic.php?p=52048#52048 ________________________________ Message 8 _____________________________________ Time: 07:44:25 AM PST US From: N5SL Subject: Re: Zenith-List: 701 seat belt attach John: As usual you bring up a very good point. I talked to Jon Croke at Oshkosh and saw his scars. Thanks for the post. I'm attaching a portion of a scan from my 601XL drawings showing the 601XL seat belt attachment. Here is a picture of mine installed since I followed the drawings while building. http://www.cooknwithgas.com/3_02_06_ELT.jpg As you can see in the photo it is not used and I attached mine further back using AN3 bolts into a 3/4" thick longeron. I did this for peace of mind. Thanks again, Scott Laughlin http://www.cooknwithgas.com/ working on Engine Cowl --- John Bolding wrote: > I have no clue if the 601 is the same design as I > don't have those drawings (somebody help me here) __________________________________________________ ________________________________ Message 9 _____________________________________ Time: 07:46:51 AM PST US From: Stanley Challgren Subject: Re: Zenith-List: Polished Aluminum --> Zenith-List message posted by: Stanley Challgren Robin: I used one pound of each of the three Nuvite polishes recommended in the 5 years of polishing my 601. Almost all of that was for the initial polishing. I would recommend at least one pound of each. I do not know of any polisher that is a reasonable alternative to the Cyclo. It costs a lot of money and works great. Stan On Aug 1, 2006, at 9:38 AM, Robin Bellach wrote: > --> Zenith-List message posted by: "Robin Bellach" > <601zv@ritternet.com> > > For those who have been there, would 1/2 lb of Nuvite C and 1/2 lb. > of S be appropriate for a 601? And is there any reasonable > alternative to the Cyclo 5 polisher for final finishing? > > ----- Original Message ----- Sent: Tuesday, August 01, 2006 10:00 AM > > ________________________________ Message 10 ____________________________________ Time: 07:50:32 AM PST US From: NYTerminat@aol.com Subject: Re: Zenith-List: 701 seat belt attach Was it the shoulder or seat tunnel attachment that let go? In a message dated 8/3/2006 10:46:41 A.M. Eastern Daylight Time, nfivesl@yahoo.com writes: John: As usual you bring up a very good point. I talked to Jon Croke at Oshkosh and saw his scars. Thanks for the post. I'm attaching a portion of a scan from my 601XL drawings showing the 601XL seat belt attachment. Here is a picture of mine installed since I followed the drawings while building. http://www.cooknwithgas.com/3_02_06_ELT.jpg As you can see in the photo it is not used and I attached mine further back using AN3 bolts into a 3/4" thick longeron. I did this for peace of mind. Thanks again, Scott Laughlin http://www.cooknwithgas.com/ working on Engine Cowl --- John Bolding wrote: > I have no clue if the 601 is the same design as I > don't have those drawings (somebody help me here) ________________________________ Message 11 ____________________________________ Time: 07:50:32 AM PST US From: Robert Schoenberger Subject: Zenith-List: 3D printers The Wall Street Journal has an interesting article today entitled "3D Printers Reshape World of Copying". The article is hopefully attached. Excuse the quality. The short and sweet is that there are printers out there which build up a 3D part or object from the computer feed. I can see all kinds of applications for our aircraft building. Making vents, special trial curved pieces, inspection covers, etc. The price isn't there yet, but it will be. Some of the listers probably have or will have these 3D printers at their real job. Robert Schoenberger 701 60% ________________________________ Message 12 ____________________________________ Time: 08:10:28 AM PST US From: "doug kandle" Subject: Zenith-List: Re: 701 seat belt attach --> Zenith-List message posted by: "doug kandle" We had a tragic accident at an airport here that shows just how difficult it is to know how to attach the seat belts. A Long EZ went off the runway and broke off the main gear. The pilot died because as the gear came off it yanked down on the shoulder harness (which was apparently attached to or near the gear). He appeared OK but died as they were loading him into the ambulance. This just goes to show that you don't want the belts attached to the strongest part of the plane, if it is at all possible for that part to be separated from your seat. I have some worry about the attachment on the side if the 701. If the gear were to be hit very hard (like by a ditch on a forced landing), then they might twist off. In that case if they don't break free, they would wind up the side of the 701 (which is exactly where the seat belt is attached). I just hope that the design has the gear retaining bolts breaking before the airframe deforms significantly. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=52063#52063 ________________________________ Message 13 ____________________________________ Time: 08:19:39 AM PST US From: "John Marzulli" Subject: Re: Zenith-List: 3D printers The technique is called rapid prototyping, and the Skunk Works recently showed an aircraft that was built using this technology. http://www.newscientisttech.com/article.ns?id=dn9602&feedId=online-news_rss20 On 8/3/06, Robert Schoenberger wrote: > > The Wall Street Journal has an interesting article today entitled "3D > Printers Reshape World of Copying". The article is hopefully attached. > Excuse the quality. The short and sweet is that there are printers out > there which build up a 3D part or object from the computer feed. I can > see all kinds of applications for our aircraft building. Making vents, > special trial curved pieces, inspection covers, etc. The price isn't > there yet, but it will be. Some of the listers probably have or will > have these 3D printers at their real job. Robert Schoenberger 701 60% > > -- John Marzulli http://701Builder.blogspot.com/ ________________________________ Message 14 ____________________________________ Time: 08:32:02 AM PST US From: "Bill Cardell" Subject: RE: Zenith-List: 3D printers --> Zenith-List message posted by: "Bill Cardell" I first one of these in action at a trade show last year, since then we've used one for three different parts. Very cool technology. They now have ones that spray a ceramic and can actually print a usable investment casting mold for a foundry. Draw a part and have a usable metal proto within a day or two. Haven't tried that one yet, very pricey. Not airplane parts, but you can see a few of the 3d parts here: http://www.flyinmiata.com/projects/new_turbos.php Do not archive Bill Cardell (TurboDog's Dad) www.flyinmiata.com 1-800-FLY-MX5S tech 970-242-3800 ________________________________ Message 15 ____________________________________ Time: 08:52:58 AM PST US From: Zed Smith Subject: Zenith-List: Re: 3D/Skunk Wrks/etc --> Zenith-List message posted by: Zed Smith UAV? I have one. I'm just trying to finish my 701 project so it'll be a MAV (Manned Aerial Vehicle). do not archive Zed/the usual......... ________________________________ Message 16 ____________________________________ Time: 09:03:39 AM PST US From: Subject: Re: Zenith-List: Re: 3D/Skunk Wrks/etc --> Zenith-List message posted by: Nope Zed, what you have there is an Unmanned Flightless Object. Ed Moody II ---- Zed Smith wrote: > --> Zenith-List message posted by: Zed Smith > > > UAV? I have one. > I'm just trying to finish my 701 project so it'll be a MAV (Manned Aerial Vehicle). > > do not archive > > Zed/the usual......... ________________________________ Message 17 ____________________________________ Time: 09:23:13 AM PST US From: TYA2 Subject: Re: Zenith-List: 701 seat belt attach --> Zenith-List message posted by: TYA2 Dear List, The issue with seat belt attachment points and their strength is not just a homebuilt aircraft problem, it exists with real commercial aircraft as well. Last week 5 people were seriously injured then their seat belt attachment points failed in a Dash 8 turboprop aircraft flying over Manitoba Canada. The Canadian Transportation Safety Board is investigating. The seat belt attachment points failed in turbulence and not in a CRASH!!. Remember we don't have a 40 g body. Rocky 1995 CH2000 ________________________________ Message 18 ____________________________________ Time: 09:27:13 AM PST US From: Paul Mulwitz Subject: Re: Zenith-List: 3D printers --> Zenith-List message posted by: Paul Mulwitz Hi Bob, This sort of equipment has been around for decades. Mechanical engineers have used them for prototyping parts to prove their designs are correct. In that sort of application, there is little interest in the mechanical strength of the parts, and the cost is only compared to hand machining costs for the same part. Alas, there are no free rides for those of us building airplanes in our garages. Paul XL fuselage At 07:49 AM 8/3/2006, you wrote: >The Wall Street Journal has an interesting article today entitled >"3D Printers Reshape World of Copying". The article is hopefully attached. >Excuse the quality. The short and sweet is that there are printers >out there which build up a 3D part or object from the computer >feed. I can see all kinds of applications for our aircraft >building. Making vents, special trial curved pieces, inspection >covers, etc. The price isn't there yet, but it will be. Some of >the listers probably have or will have these 3D printers at their >real job. Robert Schoenberger 701 60% > > ________________________________ Message 19 ____________________________________ Time: 09:30:30 AM PST US From: Zed Smith Subject: Zenith-List: Please, no more 3D!! --> Zenith-List message posted by: Zed Smith Ed, I stand corrupted. Zed do not archive, tilt, fold, spindle or mutilate ________________________________ Message 20 ____________________________________ Time: 09:42:44 AM PST US From: Tom and Bren Henderson Subject: Re: Zenith-List: 3D printers We use one of these at work for small, intricate assemblies. They're fantastic for visualization and design work. We picked it up for less than $10k, but each "part" runs us about $50 in medium (resin). Robert Schoenberger wrote: The Wall Street Journal has an interesting article today entitled "3D Printers Reshape World of Copying". The article is hopefully attached. Excuse the quality. The short and sweet is that there are printers out there which build up a 3D part or object from the computer feed. I can see all kinds of applications for our aircraft building. Making vents, special trial curved pieces, inspection covers, etc. The price isn't there yet, but it will be. Some of the listers probably have or will have these 3D printers at their real job. Robert Schoenberger 701 60% ________________________________ Message 21 ____________________________________ Time: 12:30:21 PM PST US From: "Al Young" Subject: Re: Zenith-List: 701 seat belt attach John- I can't speak to the 701 seat belt situation, but I can from first hand speak to the 601XL seat belt. A year ago, I nosed into a concrete runway in my 601XL, crushed nose wheel, bent back up into the cabin floor, prop shattered, etc etc. I didn't have a scratch as the seat belt held as it was designed to do. Last month I bounced a C-172 on a grass strip and bent the rear fuselage enough that I lost all control of rudder and elevator.(Cables loosened), End result, broken nose wheel, totaled the Cessna. I was thrown into the right side window, breaking it and my nose, head etc. The only difference in these two incidents were the Cessna didn't have a shoulder belt and the 601XL did. The seat belt on the Cessna held or I would have been a stat for the NTSB. I've got much faith in the 601XL seat belt system. As I re-build, I noticed that the 601XL seatbelt attachment points were not harmed, not even bent. Al Young 601XL ----- Original Message ----- From: John Bolding To: zenith-list@matronics.com Sent: Thursday, August 03, 2006 1:44 AM Subject: Zenith-List: 701 seat belt attach What DIFFERENCE does it make if some dimension on the seat belt attach fitting does not match a drawing when the WHOLE DAMN FITTING pulls out in an accident and lets you kiss the panel ??? This is NOT green vs. maroon scotchbrite, this is the restraint system on your aircraft which some of us on this list (and/or our friends and loved ones)will one day need and test to its limits. The 701 seat belt attach has been shown recently that it is probably/possibly (you choose)not up to the task . I have no clue if the 601 is the same design as I don't have those drawings (somebody help me here) but if it does hopefully enough folks will bug Zenith for an analysis of the failure(MAYBE it was an anamoly) and a fix, if warranted. Since Jon's accident I have looked thru my collection of about 35 homebuilt aircraft drawings (too many airplanes, not enough time) and NONE of the seat belt fittings are secured with a row of 5 pulled rivets into a single thickness of .025 aluminum. Not even close. Maybe Chris has figured out something that Thorpe, Thurston,C.G. Taylor,Van, and others didn't......If a seat belt attach fitting pulled out of a Ford and some cute 10yr old went thru a windshield you would hear about it on CNN.and 1,678 personal injury lawyers would have a collective orgasm. The engineers would be all over it NOW. This was brought up right after Jon was gracious enough to allow us post mortum pictures and the interest level was almost non-existent but since then there has been hundreds of posts of mostly fluff when compared to the importance of this (in my deranged mind anyway). If I'm playing left field without a glove somebody tell me to sit down and keep quiet. When you do, gently explain to me how 5 "poprivets" into a sheet of alum slightly thicker than a beer can is going to keep me in place at 40 G's. It didn't work with Jon. I REALLY shouldn't write stuff at 1:30 AM but I'm thick skinned so fire away!! LOW&SLOW John ________________________________ Message 22 ____________________________________ Time: 01:24:33 PM PST US From: "George Swinford" Subject: Zenith-List: Seat belt attachment Rocky writes "Remember, we don't have a 40g body." As Col Stapp's rocket sled tests proved 50 years ago, when properly restrained, we do have a 40g body. I believe current ag plane cockpit design reflects this. For many years, the standard for FAR Part 23 aircraft was 9g forward and (I believe) 4&1/2g down. Airliner passenger seats were designed to the same limits. For airliners, these values have been increased. I have not used FAR 23 in several years, so I can't quote the current values for crew restraint in light aircraft. The point is, we can benefit from increased restraint capability. My personal compromise is to get a capability for 20g forward on a 200 pound occupant, assuming the forward crash load to be equally divided between shoulder harness and seat belt. I modified my 601 restraints to realize this level of protection. It's encouraging to hear that some 601 restraints have survived certain accidents intact. Obviously, some 701 restraints have not. "You pays your money and you takes your choice". If you are satisfied with what Chris has provided, I'll be the last to criticize you. No need to start a flame war over this issue. I'll be happy to share my mods off-list with anyone who is interested. George ________________________________ Message 23 ____________________________________ Time: 01:27:27 PM PST US From: Zed Smith Subject: Zenith-List: Belt attachment --> Zenith-List message posted by: Zed Smith List, This isn't intended to prolong or enliven the aforementioned subject......however, With all the talent present on this and related Lists surely there is somebody who knows something about automobiles and the designed-in "crumple zones". Possibly some of that expertise might apply here. Obviously there are two extremes; nearly nothing and too much. We're all probably seeking something in between. I would speculate that none of us wishes to BE the crumple zone.....we'd rather walk away like Jon even if it did include some scratches. A previous post mentioned the wise addition of a shoulder strap as an augmentation to the lap strap to preclude head-banging. I'm going to stick my neck out on this one.....maybe if the belt attach brackets hold (don't jerk loose from whence they're fastened) then the remainder of the assembly (the airplane) will bend and distort while the aircraft decelerates. This accordion feature might be one of the cat's nine lives. If memory serves, a certain designer of ag aircraft intended that big parts (engine, hopper, wings, tail, etc) begin shedding themselves while the box containing the pilot stayed intact when the entire assembly unintentionally came into contact with the ground. Seems like a logical approach. Okay, slide rule jockeys, jump in any time. Maybe its the heat, Regards, Zed do not archive ________________________________ Message 24 ____________________________________ Time: 07:17:55 PM PST US From: Rick R Subject: Zenith-List: Re: Machine Shop Thanks for all the replies. Hopefully my dilemma is solved. Thanks again. DO NOT ARCHIVE Rick Sharpsburg, GA. USA http://www.n701rr.com ________________________________ Message 25 ____________________________________ Time: 10:12:43 PM PST US From: Gary Gower Subject: Re: Zenith-List: Engine for 601XL There are two things that has changed since those photos of the cracks in the empenage: The newer 912 engines has a clutch that almost ended with that shaking, I have one of this engines The newer 701 SP conversion has thicker empenage supports, Another note, that airplane was 582 powered... Saludos Gary Gower. Flying From Chapala, Mexico 701 912S Building a 601 XL (no engine choise yet). Milburn Reed wrote: I too have tentatively selected a ch 701- jabiru 2200 combination-I would welcome input so related, guided or otherwise. I have observed a hi powered ch 701 (912 Hi compression engine?) start up and shut down and it shook like a wet dog as well as emitting a large tin shed sound. I didn't think too much about the consequences until someone reported they had cracks in the empennage from such shivering. Mil Reed --------------------------------- Yahoo! Music Unlimited - Access over 1 million songs.Try it free.