---------------------------------------------------------- Europa-List Digest Archive --- Total Messages Posted Tue 11/01/05: 24 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:10 AM - 2005 Matronics Email List Fund Raiser [Please Read]... (Matt Dralle) 2. 12:32 AM - Re: Prop strikes and nose arm springs (BEBERRY@aol.com) 3. 12:42 AM - Re: fat wires (paul atkinson) 4. 12:52 AM - Re: Nose gear springs (Tim Weert) 5. 01:06 AM - Re: Nose gear springs (Gerry Holland) 6. 02:36 AM - Re: Nose gear springs (Simon Smith) 7. 03:34 AM - Re: Nose gear springs (EuropaForum) 8. 04:04 AM - Re: Nose Gear Springs (G-IANI) 9. 05:35 AM - Re: Nose Gear Springs (Alan Burrows) 10. 05:37 AM - Argentina (William Daniell) 11. 09:52 AM - Re: Nose Gear Springs (Paul Boulet) 12. 10:59 AM - Re: Nose Gear Springs (BEBERRY@aol.com) 13. 12:02 PM - Re: Nose Gear Springs (R.C.Harrison) 14. 12:20 PM - Re: Nose Gear Springs (Simon Smith) 15. 12:41 PM - Re: Nose Gear Springs (Trevpond@aol.com) 16. 01:15 PM - Re: Nose Gear Springs (Steve Hagar) 17. 01:16 PM - Re: Nose Gear Springs (Steve Hagar) 18. 01:18 PM - Springs (Steve Hagar) 19. 03:26 PM - Re: Springs (BEBERRY@aol.com) 20. 03:39 PM - Re: Argentina (Rowland Carson) 21. 04:39 PM - Re: Nose Gear Springs (Garry) 22. 05:27 PM - Re: Springs (N55XS) 23. 09:21 PM - Re: europa flyer #46 (sep 05) (JR(Bob) Gowing) 24. 09:21 PM - Re: europa flyer #46 (sep 05) (JR(Bob) Gowing) ________________________________ Message 1 _____________________________________ Time: 12:10:09 AM PST US From: Matt Dralle Subject: Europa-List: 2005 Matronics Email List Fund Raiser [Please Read]... --> Europa-List message posted by: Matt Dralle Dear Matronics Email Listers, Each year during the month of November, I hold a PBS-like fund raiser to support the Email Lists sponsored here. As you have probably noticed, there is no commercial advertising on any of the List-related web pages or in any of the email distributions. The Matronics Lists are supported completely though the generous Contributions of its members. Making a Contribution to support the continued operation and upgrade of the Matronics Aviation Lists is completely voluntary, but I encourage you to consider making a donation that is equal to the value and entertainment you have received from these Lists over the past year. And thanks to a number of extremely generous members/businessmen found on the Lists, there are some truly awesome Free Gifts to be had during this year's List Fund Raiser! Andy Gold of the The Builder's Bookstore, Paul Besing of Aeroware Enterprises, and Jon Croke of Homebuilt HELP have all contributed products from their respective catalogs in support of this year's Fund Raiser! Thank you! Andy, Paul, and Jon are great guys and I really appreciate their support for the Lists. I encourage each List member to visit their respective web sites for a closer look at each of their great product lines. Its guys like these that make this such a great hobby/sport to be a part of! I have included links to each of their web sites below. And just like PBS, I will be making pretty regular reminder requests throughout the month of November. I ask for your kind consideration and understanding during this time and realize that this Fund Raiser is the *only* source of financing and support I have for these Lists. I am continually upgrading and improving the hardware and systems required in support of the Lists. This year saw a substantial upgrade to all of the computer room infrastructure including gigabit networking, dedicated air conditioning, an equipment rack, and high-performance system chassis upgrades. Yes, it was expensive, but I feel the Lists are worth it! Hopefully you do too! All of these upgrades are what add up to the High-Performance, Highly-Available system that everyone has come to expect of the Email Lists at Matronics. Please make a Contribution today to support these upgrades and the continued operation of the Matronics Email Lists. The Contribution web site is fast, easy, and secure to use. You can even select a sweet Free Gift with a qualifying Contribution amount. The Contribution Site can be found here: http://www.matronics.com/contribution Thank you for your generous support!! Matt Dralle Matronics Email List Administrator Sponsors of this Year's Matronics List Fund Raiser Andy Gold - The Builder's Bookstore - http://www.buildersbooks.com Paul Besing - Aeroware Enterprises - http://www.kitlog.com Jon Croke - Homebuilt HELP - http://www.homebuilthelp.com Matt G Dralle | Matronics | PO Box 347 | Livermore | CA | 94551 925-606-1001 V | 925-606-6281 F | dralle@matronics.com Email http://www.matronics.com/ WWW | Featuring Products For Aircraft do not archive ________________________________ Message 2 _____________________________________ Time: 12:32:17 AM PST US From: BEBERRY@aol.com Subject: Re: Europa-List: Prop strikes and nose arm springs --> Europa-List message posted by: BEBERRY@aol.com Oh-oh, On reading this last I suddenly realised I should have gone to bed. This topic refers to tri-gears......... Out of my league. Please disregard! Ferg I know the feeling Ferg!. Thanks for the reply, Patrick ________________________________ Message 3 _____________________________________ Time: 12:42:23 AM PST US Subject: Europa-List: Re: fat wires From: "paul atkinson" --> Europa-List message posted by: "paul atkinson" Thanks to Colin, Jim, Fred and Nigel for your insights. I've been plugging away at it, without an answer yet, but now have a much better idea what to look for. Regards Paul ________________________________ Message 4 _____________________________________ Time: 12:52:34 AM PST US From: "Tim Weert" Subject: Re: Europa-List: Nose gear springs --> Europa-List message posted by: "Tim Weert" Hi Gerry, I placed some pics in http://www.europaowners.org/modules.php?set_albumName=album135&op=modload&name=gallery&file=index&include=view_album.php Regards, Tim. ________________________________ Message 5 _____________________________________ Time: 01:06:20 AM PST US Subject: Re: Europa-List: Nose gear springs From: Gerry Holland --> Europa-List message posted by: Gerry Holland > I placed some pics in > http://www.europaowners.org/modules.php?set_albumName=album135&op=modload&name > =gallery&file=index&include=view_album.php Thanks Tim. Much appreciated! Gerry Do not archive ________________________________ Message 6 _____________________________________ Time: 02:36:21 AM PST US From: "Simon Smith" Subject: RE: Europa-List: Nose gear springs --> Europa-List message posted by: "Simon Smith" I remember looking at SE-XRX at Kemble 2004 and it had springs set in an alloy block that worked in compression rather than tension. Maybe something to consider? Simon ________________________________ Message 7 _____________________________________ Time: 03:34:47 AM PST US From: EuropaForum Subject: Re: Europa-List: Nose gear springs --> Europa-List message posted by: EuropaForum This should work also if the long URL is broken for someone. http://www.europaowners.org/album135 Steved > I placed some pics in > http://www.europaowners.org/modules.php? > set_albumName=album135&op=modload&name=gallery&file=index&include=view > _album.php > > Regards, Tim. ________________________________ Message 8 _____________________________________ Time: 04:04:47 AM PST US From: "G-IANI" Subject: RE: Europa-List: Nose Gear Springs --> Europa-List message posted by: "G-IANI" Thanks to all those who have declared an interest in the Trigear bungee replacement springs. At this moment 13 builders have said they are interested. Here is some background so you know where we have got to. Two springs have been used to replace the nose wheel bungee and this has been done on at least five aircraft (on the Dutch register). The spring specification was done by Nico Groot and it took three attempts to get a suitable spec. Andy Draper was aware that the work was being done and had some reservation as to how successful it might be. Those who have them are very happy with the result. I have produced a drawing of the spring (complete with English translation of the specification) and calculated forces "on the stop" and at the extreme of the spring travel (hitting the wire stop). Andy's reservation was that the spring rate (Young's modulus) of the spring is much higher than that of the bungee. The modulus of a steel spring is linear whereas that of the bungee is highly non linear. This is because a) The Young's modulus of rubber is non linear, b) the bungee is multi strand, c) the sheath probably plays a significant role, d) the bungee may have a safety thread, e) the installation may have anything from 12 to 20 working strands and f) these may be of two lengths. So the Young's modulus of your bungee might anything. Based on some very crude measurements I think mine may be about 25N/mm. The spring rate of the two springs is 65N/mm. While this arithmetic is interesting it is somewhat academic as only about half the load on the nose wheel is known (the weight of the aircraft). The remaining loads are dynamic loads caused by bumps so they are almost impossible to quantify. I have talked this through with Andy and reached the following conclusion:- a) The initial springing is done by the nose leg, just as with the bungee. b) Once the nose leg is bounced off the stop the spring will give a "harder" ride but this may prevent the wire stop being reached. In fact the higher spring rate may actually reduce the chance of a bent leg or prop strike. c) Once the nose leg hits the stop, and if sufficient further force is applied, the nose leg is going to bend. Following this logic, as long as the spring tension at full extension to the stop (wire loop) is less than the strain at which the nose leg will bend then there is no disadvantage to using the springs. Andy has offered to do the calculations on the strain needed to bend the nose leg. Andy does not wish to see the protection, against bending the nose wheel leg lost. The disadvantage of using the spring is a weight increase of about 1KG. The advantage is "fit and forget" and less blood on the floor. Assuming Andy is satisfied that the springs do not significantly increase the danger of bending the nose leg then I will get a modification application off to the PFA as soon as possible (the paperwork is already prepared). If Andy's calculations suggest these springs could be a problem then we may have to look at the spring design again. Everyone should be aware that the details on my drawing are more a requirement than a complete specification. They do not specify the material, heat treatment etc so my remarks apply to only those springs made by the Dutch manufacturer. It will be perfectly possible for others to manufacture suitable springs but it will require some development work and may not be cost effective. As Tim Weert has clearly explained (his posting dated 31/10/2005) the manufacturing cost of the springs has a high fixed overhead. To offset this it will be of great benefit to order in bulk. My preference would be for Europa(2004) to handle this but I am prepared, if necessary, to act as co-ordinator. I will keep you all informed as to progress. Ian Rickard #505 G-IANI XS Trigear Europa Club Mods Rep (Trigear) e-mail mods@europaclub.org.uk or direct g-iani@ntlworld.com ________________________________ Message 9 _____________________________________ Time: 05:35:50 AM PST US From: "Alan Burrows" Subject: RE: Europa-List: Nose Gear Springs --> Europa-List message posted by: "Alan Burrows" Hi Ian If I'm not already on the list, please add me to it, also if Europa choose not to stock the springs, then let me know & I will help if required. Cheers Alan -----Original Message----- From: owner-europa-list-server@matronics.com [mailto:owner-europa-list-server@matronics.com] On Behalf Of G-IANI Subject: RE: Europa-List: Nose Gear Springs --> Europa-List message posted by: "G-IANI" Thanks to all those who have declared an interest in the Trigear bungee replacement springs. At this moment 13 builders have said they are interested. Here is some background so you know where we have got to. Two springs have been used to replace the nose wheel bungee and this has been done on at least five aircraft (on the Dutch register). The spring specification was done by Nico Groot and it took three attempts to get a suitable spec. Andy Draper was aware that the work was being done and had some reservation as to how successful it might be. Those who have them are very happy with the result. I have produced a drawing of the spring (complete with English translation of the specification) and calculated forces "on the stop" and at the extreme of the spring travel (hitting the wire stop). Andy's reservation was that the spring rate (Young's modulus) of the spring is much higher than that of the bungee. The modulus of a steel spring is linear whereas that of the bungee is highly non linear. This is because a) The Young's modulus of rubber is non linear, b) the bungee is multi strand, c) the sheath probably plays a significant role, d) the bungee may have a safety thread, e) the installation may have anything from 12 to 20 working strands and f) these may be of two lengths. So the Young's modulus of your bungee might anything. Based on some very crude measurements I think mine may be about 25N/mm. The spring rate of the two springs is 65N/mm. While this arithmetic is interesting it is somewhat academic as only about half the load on the nose wheel is known (the weight of the aircraft). The remaining loads are dynamic loads caused by bumps so they are almost impossible to quantify. I have talked this through with Andy and reached the following conclusion:- a) The initial springing is done by the nose leg, just as with the bungee. b) Once the nose leg is bounced off the stop the spring will give a "harder" ride but this may prevent the wire stop being reached. In fact the higher spring rate may actually reduce the chance of a bent leg or prop strike. c) Once the nose leg hits the stop, and if sufficient further force is applied, the nose leg is going to bend. Following this logic, as long as the spring tension at full extension to the stop (wire loop) is less than the strain at which the nose leg will bend then there is no disadvantage to using the springs. Andy has offered to do the calculations on the strain needed to bend the nose leg. Andy does not wish to see the protection, against bending the nose wheel leg lost. The disadvantage of using the spring is a weight increase of about 1KG. The advantage is "fit and forget" and less blood on the floor. Assuming Andy is satisfied that the springs do not significantly increase the danger of bending the nose leg then I will get a modification application off to the PFA as soon as possible (the paperwork is already prepared). If Andy's calculations suggest these springs could be a problem then we may have to look at the spring design again. Everyone should be aware that the details on my drawing are more a requirement than a complete specification. They do not specify the material, heat treatment etc so my remarks apply to only those springs made by the Dutch manufacturer. It will be perfectly possible for others to manufacture suitable springs but it will require some development work and may not be cost effective. As Tim Weert has clearly explained (his posting dated 31/10/2005) the manufacturing cost of the springs has a high fixed overhead. To offset this it will be of great benefit to order in bulk. My preference would be for Europa(2004) to handle this but I am prepared, if necessary, to act as co-ordinator. I will keep you all informed as to progress. Ian Rickard #505 G-IANI XS Trigear Europa Club Mods Rep (Trigear) e-mail mods@europaclub.org.uk or direct g-iani@ntlworld.com ________________________________ Message 10 ____________________________________ Time: 05:37:40 AM PST US From: "William Daniell" Subject: Europa-List: Argentina --> Europa-List message posted by: "William Daniell" Any builders in Argentina?? Will -----Original Message----- From: owner-europa-list-server@matronics.com [mailto:owner-europa-list-server@matronics.com] On Behalf Of EuropaForum Subject: Re: Europa-List: Nose gear springs --> Europa-List message posted by: EuropaForum This should work also if the long URL is broken for someone. http://www.europaowners.org/album135 Steved > I placed some pics in > http://www.europaowners.org/modules.php? > set_albumName=album135&op=modload&name=gallery&file=index&include=view > _album.php > > Regards, Tim. ________________________________ Message 11 ____________________________________ Time: 09:52:43 AM PST US From: Paul Boulet Subject: RE: Europa-List: Nose Gear Springs --> Europa-List message posted by: Paul Boulet I'm willing to be point man for U.S. collection/distribution if needed Paul Boulet, N914PB Malibu, CA G-IANI wrote: --> Europa-List message posted by: "G-IANI" Thanks to all those who have declared an interest in the Trigear bungee replacement springs. At this moment 13 builders have said they are interested. Here is some background so you know where we have got to. Two springs have been used to replace the nose wheel bungee and this has been done on at least five aircraft (on the Dutch register). The spring specification was done by Nico Groot and it took three attempts to get a suitable spec. Andy Draper was aware that the work was being done and had some reservation as to how successful it might be. Those who have them are very happy with the result. I have produced a drawing of the spring (complete with English translation of the specification) and calculated forces "on the stop" and at the extreme of the spring travel (hitting the wire stop). Andy's reservation was that the spring rate (Young's modulus) of the spring is much higher than that of the bungee. The modulus of a steel spring is linear whereas that of the bungee is highly non linear. This is because a) The Young's modulus of rubber is non linear, b) the bungee is multi strand, c) the sheath probably plays a significant role, d) the bungee may have a safety thread, e) the installation may have anything from 12 to 20 working strands and f) these may be of two lengths. So the Young's modulus of your bungee might anything. Based on some very crude measurements I think mine may be about 25N/mm. The spring rate of the two springs is 65N/mm. While this arithmetic is interesting it is somewhat academic as only about half the load on the nose wheel is known (the weight of the aircraft). The remaining loads are dynamic loads caused by bumps so they are almost impossible to quantify. I have talked this through with Andy and reached the following conclusion:- a) The initial springing is done by the nose leg, just as with the bungee. b) Once the nose leg is bounced off the stop the spring will give a "harder" ride but this may prevent the wire stop being reached. In fact the higher spring rate may actually reduce the chance of a bent leg or prop strike. c) Once the nose leg hits the stop, and if sufficient further force is applied, the nose leg is going to bend. Following this logic, as long as the spring tension at full extension to the stop (wire loop) is less than the strain at which the nose leg will bend then there is no disadvantage to using the springs. Andy has offered to do the calculations on the strain needed to bend the nose leg. Andy does not wish to see the protection, against bending the nose wheel leg lost. The disadvantage of using the spring is a weight increase of about 1KG. The advantage is "fit and forget" and less blood on the floor. Assuming Andy is satisfied that the springs do not significantly increase the danger of bending the nose leg then I will get a modification application off to the PFA as soon as possible (the paperwork is already prepared). If Andy's calculations suggest these springs could be a problem then we may have to look at the spring design again. Everyone should be aware that the details on my drawing are more a requirement than a complete specification. They do not specify the material, heat treatment etc so my remarks apply to only those springs made by the Dutch manufacturer. It will be perfectly possible for others to manufacture suitable springs but it will require some development work and may not be cost effective. As Tim Weert has clearly explained (his posting dated 31/10/2005) the manufacturing cost of the springs has a high fixed overhead. To offset this it will be of great benefit to order in bulk. My preference would be for Europa(2004) to handle this but I am prepared, if necessary, to act as co-ordinator. I will keep you all informed as to progress. Ian Rickard #505 G-IANI XS Trigear Europa Club Mods Rep (Trigear) e-mail mods@europaclub.org.uk or direct g-iani@ntlworld.com ________________________________ Message 12 ____________________________________ Time: 10:59:19 AM PST US From: BEBERRY@aol.com Subject: Re: Europa-List: Nose Gear Springs --> Europa-List message posted by: BEBERRY@aol.com As soon as I know the spring costs I will probably add my name. Patrick ________________________________ Message 13 ____________________________________ Time: 12:02:34 PM PST US From: "R.C.Harrison" Subject: RE: Europa-List: Nose Gear Springs --> Europa-List message posted by: "R.C.Harrison" Hi! Subject to PFA Mod approval Remembering that my bump stop is now upside down due to having had a Bungee failure, and the ultimate price I would vbe seriously interested in a set. Regards Bob Harrison G-PTAG Europa MKI/Jabiru 3300 -----Original Message----- From: owner-europa-list-server@matronics.com [mailto:owner-europa-list-server@matronics.com] On Behalf Of G-IANI Subject: RE: Europa-List: Nose Gear Springs --> Europa-List message posted by: "G-IANI" Thanks to all those who have declared an interest in the Trigear bungee replacement springs. At this moment 13 builders have said they are interested. Here is some background so you know where we have got to. Two springs have been used to replace the nose wheel bungee and this has been done on at least five aircraft (on the Dutch register). The spring specification was done by Nico Groot and it took three attempts to get a suitable spec. Andy Draper was aware that the work was being done and had some reservation as to how successful it might be. Those who have them are very happy with the result. I have produced a drawing of the spring (complete with English translation of the specification) and calculated forces "on the stop" and at the extreme of the spring travel (hitting the wire stop). Andy's reservation was that the spring rate (Young's modulus) of the spring is much higher than that of the bungee. The modulus of a steel spring is linear whereas that of the bungee is highly non linear. This is because a) The Young's modulus of rubber is non linear, b) the bungee is multi strand, c) the sheath probably plays a significant role, d) the bungee may have a safety thread, e) the installation may have anything from 12 to 20 working strands and f) these may be of two lengths. So the Young's modulus of your bungee might anything. Based on some very crude measurements I think mine may be about 25N/mm. The spring rate of the two springs is 65N/mm. While this arithmetic is interesting it is somewhat academic as only about half the load on the nose wheel is known (the weight of the aircraft). The remaining loads are dynamic loads caused by bumps so they are almost impossible to quantify. I have talked this through with Andy and reached the following conclusion:- a) The initial springing is done by the nose leg, just as with the bungee. b) Once the nose leg is bounced off the stop the spring will give a "harder" ride but this may prevent the wire stop being reached. In fact the higher spring rate may actually reduce the chance of a bent leg or prop strike. c) Once the nose leg hits the stop, and if sufficient further force is applied, the nose leg is going to bend. Following this logic, as long as the spring tension at full extension to the stop (wire loop) is less than the strain at which the nose leg will bend then there is no disadvantage to using the springs. Andy has offered to do the calculations on the strain needed to bend the nose leg. Andy does not wish to see the protection, against bending the nose wheel leg lost. The disadvantage of using the spring is a weight increase of about 1KG. The advantage is "fit and forget" and less blood on the floor. Assuming Andy is satisfied that the springs do not significantly increase the danger of bending the nose leg then I will get a modification application off to the PFA as soon as possible (the paperwork is already prepared). If Andy's calculations suggest these springs could be a problem then we may have to look at the spring design again. Everyone should be aware that the details on my drawing are more a requirement than a complete specification. They do not specify the material, heat treatment etc so my remarks apply to only those springs made by the Dutch manufacturer. It will be perfectly possible for others to manufacture suitable springs but it will require some development work and may not be cost effective. As Tim Weert has clearly explained (his posting dated 31/10/2005) the manufacturing cost of the springs has a high fixed overhead. To offset this it will be of great benefit to order in bulk. My preference would be for Europa(2004) to handle this but I am prepared, if necessary, to act as co-ordinator. I will keep you all informed as to progress. Ian Rickard #505 G-IANI XS Trigear Europa Club Mods Rep (Trigear) e-mail mods@europaclub.org.uk or direct g-iani@ntlworld.com ________________________________ Message 14 ____________________________________ Time: 12:20:40 PM PST US From: "Simon Smith" Subject: RE: Europa-List: Nose Gear Springs --> Europa-List message posted by: "Simon Smith" Count me in too. (As long as we are not talking silly money)! Simon 504 ________________________________ Message 15 ____________________________________ Time: 12:41:55 PM PST US From: Trevpond@aol.com Subject: Re: Europa-List: Nose Gear Springs --> Europa-List message posted by: Trevpond@aol.com Hi, Put me down for a set if PFA approval is given. Trev Pond Kit 598 ________________________________ Message 16 ____________________________________ Time: 01:15:52 PM PST US From: "Steve Hagar" Subject: RE: Europa-List: Nose Gear Springs --> Europa-List message posted by: "Steve Hagar" In my job as a manufacturing engineer in a plant I have occasion to use different springs. The characteristics of the spring are wholly determined the material, diameter of the wire and diameter of the coil. There arre several if not many houses out there who do nothing but wind springs. Many are standard and do not have to be specially made. In following this thread about the springs I seem to get the impression that every one thinks there is a special recipe to get these springs from a special unique supplier. What you want is an extension spring with a certain diameter wire, certain diameter coil and of a certain length. You can call Lee Spring, or Capitol spring or many others to see if is one of their stock units or what it would take for them to wind it special which they do all the time. You can find them on the internet. Steve Hagar A143 Mesa, AZ Steve Hagar hagargs@earthlink.net > [Original Message] > From: Paul Boulet > To: > Date: 11/1/2005 10:51:20 AM > Subject: RE: Europa-List: Nose Gear Springs > > --> Europa-List message posted by: Paul Boulet > > I'm willing to be point man for U.S. collection/distribution if needed > > Paul Boulet, N914PB > Malibu, CA > > G-IANI wrote: > --> Europa-List message posted by: "G-IANI" > > > Thanks to all those who have declared an interest in the Trigear bungee > replacement springs. At this moment 13 builders have said they are > interested. > > Here is some background so you know where we have got to. > > Two springs have been used to replace the nose wheel bungee and this has > been done on at least five aircraft (on the Dutch register). The spring > specification was done by Nico Groot and it took three attempts to get a > suitable spec. Andy Draper was aware that the work was being done and had > some reservation as to how successful it might be. Those who have them are > very happy with the result. > > I have produced a drawing of the spring (complete with English translation > of the specification) and calculated forces "on the stop" and at the extreme > of the spring travel (hitting the wire stop). > > Andy's reservation was that the spring rate (Young's modulus) of the spring > is much higher than that of the bungee. The modulus of a steel spring is > linear whereas that of the bungee is highly non linear. This is because a) > The Young's modulus of rubber is non linear, b) the bungee is multi strand, > c) the sheath probably plays a significant role, d) the bungee may have a > safety thread, e) the installation may have anything from 12 to 20 working > strands and f) these may be of two lengths. So the Young's modulus of your > bungee might anything. Based on some very crude measurements I think mine > may be about 25N/mm. The spring rate of the two springs is 65N/mm. While > this arithmetic is interesting it is somewhat academic as only about half > the load on the nose wheel is known (the weight of the aircraft). The > remaining loads are dynamic loads caused by bumps so they are almost > impossible to quantify. > > I have talked this through with Andy and reached the following conclusion:- > > a) The initial springing is done by the nose leg, just as with the bungee. > b) Once the nose leg is bounced off the stop the spring will give a "harder" > ride but this may prevent the wire stop being reached. In fact the higher > spring rate may actually reduce the chance of a bent leg or prop strike. > c) Once the nose leg hits the stop, and if sufficient further force is > applied, the nose leg is going to bend. > > Following this logic, as long as the spring tension at full extension to the > stop (wire loop) is less than the strain at which the nose leg will bend > then there is no disadvantage to using the springs. Andy has offered to do > the calculations on the strain needed to bend the nose leg. Andy does not > wish to see the protection, against bending the nose wheel leg lost. > > The disadvantage of using the spring is a weight increase of about 1KG. The > advantage is "fit and forget" and less blood on the floor. > > Assuming Andy is satisfied that the springs do not significantly increase > the danger of bending the nose leg then I will get a modification > application off to the PFA as soon as possible (the paperwork is already > prepared). If Andy's calculations suggest these springs could be a problem > then we may have to look at the spring design again. > > Everyone should be aware that the details on my drawing are more a > requirement than a complete specification. They do not specify the material, > heat treatment etc so my remarks apply to only those springs made by the > Dutch manufacturer. It will be perfectly possible for others to manufacture > suitable springs but it will require some development work and may not be > cost effective. > > As Tim Weert has clearly explained (his posting dated 31/10/2005) the > manufacturing cost of the springs has a high fixed overhead. To offset this > it will be of great benefit to order in bulk. My preference would be for > Europa(2004) to handle this but I am prepared, if necessary, to act as > co-ordinator. > > I will keep you all informed as to progress. > > Ian Rickard #505 G-IANI XS Trigear > Europa Club Mods Rep (Trigear) > e-mail mods@europaclub.org.uk > or direct g-iani@ntlworld.com > > ________________________________ Message 17 ____________________________________ Time: 01:16:52 PM PST US From: "Steve Hagar" Subject: RE: Europa-List: Nose Gear Springs --> Europa-List message posted by: "Steve Hagar" Paul: I meant to send that previous message to the whole list and not just reply to you. Sorry Steve Steve Hagar hagargs@earthlink.net > [Original Message] > From: Paul Boulet > To: > Date: 11/1/2005 10:51:20 AM > Subject: RE: Europa-List: Nose Gear Springs > > --> Europa-List message posted by: Paul Boulet > > I'm willing to be point man for U.S. collection/distribution if needed > > Paul Boulet, N914PB > Malibu, CA > > G-IANI wrote: > --> Europa-List message posted by: "G-IANI" > > > Thanks to all those who have declared an interest in the Trigear bungee > replacement springs. At this moment 13 builders have said they are > interested. > > Here is some background so you know where we have got to. > > Two springs have been used to replace the nose wheel bungee and this has > been done on at least five aircraft (on the Dutch register). The spring > specification was done by Nico Groot and it took three attempts to get a > suitable spec. Andy Draper was aware that the work was being done and had > some reservation as to how successful it might be. Those who have them are > very happy with the result. > > I have produced a drawing of the spring (complete with English translation > of the specification) and calculated forces "on the stop" and at the extreme > of the spring travel (hitting the wire stop). > > Andy's reservation was that the spring rate (Young's modulus) of the spring > is much higher than that of the bungee. The modulus of a steel spring is > linear whereas that of the bungee is highly non linear. This is because a) > The Young's modulus of rubber is non linear, b) the bungee is multi strand, > c) the sheath probably plays a significant role, d) the bungee may have a > safety thread, e) the installation may have anything from 12 to 20 working > strands and f) these may be of two lengths. So the Young's modulus of your > bungee might anything. Based on some very crude measurements I think mine > may be about 25N/mm. The spring rate of the two springs is 65N/mm. While > this arithmetic is interesting it is somewhat academic as only about half > the load on the nose wheel is known (the weight of the aircraft). The > remaining loads are dynamic loads caused by bumps so they are almost > impossible to quantify. > > I have talked this through with Andy and reached the following conclusion:- > > a) The initial springing is done by the nose leg, just as with the bungee. > b) Once the nose leg is bounced off the stop the spring will give a "harder" > ride but this may prevent the wire stop being reached. In fact the higher > spring rate may actually reduce the chance of a bent leg or prop strike. > c) Once the nose leg hits the stop, and if sufficient further force is > applied, the nose leg is going to bend. > > Following this logic, as long as the spring tension at full extension to the > stop (wire loop) is less than the strain at which the nose leg will bend > then there is no disadvantage to using the springs. Andy has offered to do > the calculations on the strain needed to bend the nose leg. Andy does not > wish to see the protection, against bending the nose wheel leg lost. > > The disadvantage of using the spring is a weight increase of about 1KG. The > advantage is "fit and forget" and less blood on the floor. > > Assuming Andy is satisfied that the springs do not significantly increase > the danger of bending the nose leg then I will get a modification > application off to the PFA as soon as possible (the paperwork is already > prepared). If Andy's calculations suggest these springs could be a problem > then we may have to look at the spring design again. > > Everyone should be aware that the details on my drawing are more a > requirement than a complete specification. They do not specify the material, > heat treatment etc so my remarks apply to only those springs made by the > Dutch manufacturer. It will be perfectly possible for others to manufacture > suitable springs but it will require some development work and may not be > cost effective. > > As Tim Weert has clearly explained (his posting dated 31/10/2005) the > manufacturing cost of the springs has a high fixed overhead. To offset this > it will be of great benefit to order in bulk. My preference would be for > Europa(2004) to handle this but I am prepared, if necessary, to act as > co-ordinator. > > I will keep you all informed as to progress. > > Ian Rickard #505 G-IANI XS Trigear > Europa Club Mods Rep (Trigear) > e-mail mods@europaclub.org.uk > or direct g-iani@ntlworld.com > > ________________________________ Message 18 ____________________________________ Time: 01:18:56 PM PST US From: "Steve Hagar" Subject: Europa-List: Springs 2.08 DATE_IN_FUTURE_24_48 Date: is 24 to 48 hours after Received: date --> Europa-List message posted by: "Steve Hagar" In my job as a manufacturing engineer in a plant I have occasion to use different springs. The characteristics of the spring are wholly determined the material, diameter of the wire and diameter of the coil. There arre several if not many houses out there who do nothing but wind springs. Many are standard and do not have to be specially made. In following this thread about the springs I seem to get the impression that every one thinks there is a special recipe to get these springs from a special unique supplier. What you want is an extension spring with a certain diameter wire, certain diameter coil and of a certain length. You can call Lee Spring, or Capitol spring or many others to see if is one of their stock units or what it would take for them to wind it special which they do all the time. You can find them on the internet. Steve Hagar A143 Mesa, AZ Steve Hagar hagargs@earthlink.net ________________________________ Message 19 ____________________________________ Time: 03:26:07 PM PST US From: BEBERRY@aol.com Subject: Re: Europa-List: Springs --> Europa-List message posted by: BEBERRY@aol.com from...Steve Hagar A143 Mesa, AZ In my job as a manufacturing engineer in a plant I have occasion to use different springs. The characteristics of the spring are wholly determined the material, diameter of the wire and diameter of the coil. There arre several if not many houses out ................... I am sure that Steve is right and I would think that there are numerous manufacturers in the U.K. who would be able to supply springs off the shelf to the required spec. If someone who is a boffin on these matters can supply the correct spec I will undertake to get quotes from my contacts in the steel industry in Sheffield. Patrick ________________________________ Message 20 ____________________________________ Time: 03:39:25 PM PST US From: Rowland Carson Subject: Re: Europa-List: Argentina --> Europa-List message posted by: Rowland Carson At 2005-11-01 08:37 -0500 William Daniell wrote: >Any builders in Argentina?? Will - the only ones I know of are: kit mark builder ARG001 Oscar Ogas ARG002 LV-X263 Oscar Martinelli ARG003 LV-X275 Luis Fernndez (Europa Club member) More info about them is available on the Europa Club CD-ROM, issued to all new members. The Data Protection Act prevents release of personal details to non-members. Club Committee member Nigel Charles has visited with Luis on his stopovers there and found him very congenial. Your old pal David Corbett from Shobdon keeps telling me to twist your arm to join the Club, but with the very unreliable postal service in Colombia it seems that may not be a cost-effective move for you - unless and until we establish an online-only membership category. The membership database I am still polishing prior to transfer to Gerry has provision for that; the Committee have discussed it in the past, but no decision has been reached. regards Rowland -- | Rowland Carson (retiring) Europa Club Membership Secretary - email for info! | Europa 435 G-ROWI (750 hours building) PFA #16532 | e-mail website ________________________________ Message 21 ____________________________________ Time: 04:39:33 PM PST US From: "Garry" Subject: Re: Europa-List: Nose Gear Springs --> Europa-List message posted by: "Garry" Same here. If I'm not already on the list, please add me. Garry Stout ----- Original Message ----- From: "Alan Burrows" Subject: RE: Europa-List: Nose Gear Springs > --> Europa-List message posted by: "Alan Burrows" > > > Hi Ian > > If I'm not already on the list, please add me to it, also if Europa > choose not to stock the springs, then let me know & I will help if > required. > Cheers > > Alan > > -----Original Message----- > From: owner-europa-list-server@matronics.com > [mailto:owner-europa-list-server@matronics.com] On Behalf Of G-IANI > To: europa-list@matronics.com > Subject: RE: Europa-List: Nose Gear Springs > > > --> Europa-List message posted by: "G-IANI" > > > Thanks to all those who have declared an interest in the Trigear bungee > replacement springs. At this moment 13 builders have said they are > interested. > > Here is some background so you know where we have got to. > > Two springs have been used to replace the nose wheel bungee and this has > been done on at least five aircraft (on the Dutch register). The spring > specification was done by Nico Groot and it took three attempts to get a > suitable spec. Andy Draper was aware that the work was being done and > had some reservation as to how successful it might be. Those who have > them are very happy with the result. > > I have produced a drawing of the spring (complete with English > translation of the specification) and calculated forces "on the stop" > and at the extreme of the spring travel (hitting the wire stop). > > Andy's reservation was that the spring rate (Young's modulus) of the > spring is much higher than that of the bungee. The modulus of a steel > spring is linear whereas that of the bungee is highly non linear. This > is because a) The Young's modulus of rubber is non linear, b) the bungee > is multi strand, > c) the sheath probably plays a significant role, d) the bungee may have > a safety thread, e) the installation may have anything from 12 to 20 > working strands and f) these may be of two lengths. So the Young's > modulus of your bungee might anything. Based on some very crude > measurements I think mine may be about 25N/mm. The spring rate of the > two springs is 65N/mm. While this arithmetic is interesting it is > somewhat academic as only about half the load on the nose wheel is known > (the weight of the aircraft). The remaining loads are dynamic loads > caused by bumps so they are almost impossible to quantify. > > I have talked this through with Andy and reached the following > conclusion:- > > a) The initial springing is done by the nose leg, just as with the > bungee. > b) Once the nose leg is bounced off the stop the spring will give a > "harder" ride but this may prevent the wire stop being reached. In fact > the higher spring rate may actually reduce the chance of a bent leg or > prop strike. > c) Once the nose leg hits the stop, and if sufficient further force is > applied, the nose leg is going to bend. > > Following this logic, as long as the spring tension at full extension to > the stop (wire loop) is less than the strain at which the nose leg will > bend then there is no disadvantage to using the springs. Andy has > offered to do the calculations on the strain needed to bend the nose > leg. Andy does not wish to see the protection, against bending the nose > wheel leg lost. > > The disadvantage of using the spring is a weight increase of about 1KG. > The advantage is "fit and forget" and less blood on the floor. > > Assuming Andy is satisfied that the springs do not significantly > increase the danger of bending the nose leg then I will get a > modification application off to the PFA as soon as possible (the > paperwork is already prepared). If Andy's calculations suggest these > springs could be a problem then we may have to look at the spring design > again. > > Everyone should be aware that the details on my drawing are more a > requirement than a complete specification. They do not specify the > material, heat treatment etc so my remarks apply to only those springs > made by the Dutch manufacturer. It will be perfectly possible for > others to manufacture suitable springs but it will require some > development work and may not be cost effective. > > As Tim Weert has clearly explained (his posting dated 31/10/2005) the > manufacturing cost of the springs has a high fixed overhead. To offset > this it will be of great benefit to order in bulk. My preference would > be for > Europa(2004) to handle this but I am prepared, if necessary, to act as > co-ordinator. > > I will keep you all informed as to progress. > > Ian Rickard #505 G-IANI XS Trigear > Europa Club Mods Rep (Trigear) > e-mail mods@europaclub.org.uk > or direct g-iani@ntlworld.com > > > ________________________________ Message 22 ____________________________________ Time: 05:27:19 PM PST US From: N55XS Subject: Re: Europa-List: Springs --> Europa-List message posted by: N55XS Steve, How would one go about determining the technical requirements for the Europa springs? Jeff - N55XS 99.9 hours Steve Hagar wrote: >--> Europa-List message posted by: "Steve Hagar" > >In my job as a manufacturing engineer in a plant I have occasion to use different springs. The characteristics of the spring are wholly determined the material, diameter of the wire and diameter of the coil. There arre several if not many houses out there who do nothing but wind springs. Many are standard and do not have to be specially made. In following this thread about the springs I seem to get the impression that every one thinks there is a special recipe to get these springs from a special unique supplier. What you want is an extension spring with a certain diameter wire, certain diameter coil and of a certain length. You can call Lee Spring, or Capitol spring or many others to see if is one of their stock units or what it would take for them to wind it special which they do all the time. You can find them on the internet. > >Steve Hagar >A143 >Mesa, AZ > > >Steve Hagar >hagargs@earthlink.net > > > > -- ________________________________ Message 23 ____________________________________ Time: 09:21:16 PM PST US From: "JR(Bob) Gowing" Subject: Re: Europa-List: europa flyer #46 (sep 05) --> Europa-List message posted by: "JR(Bob) Gowing" Well spoken Mike Duane! A small number usually carries the load - I add my thanks. JR (Bob) Gowing 327 in Oz do not archive. ----- Original Message ----- From: Subject: Re: Europa-List: europa flyer #46 (sep 05) > --> Europa-List message posted by: DuaneFamly@aol.com > > Rowland and Peter, > > I have been in groups where there is a small clic of people that have most of > the work fall upon them. This is to let you know that I, and hopefully all > the other Europaphiles, understand that people do have jobs and a personal life > that need to come first. That the job you do is big part of the success of > this group. I want to thank you two for all the unsung effort put in and will > accept the Europa Flyer gratefully when I receive it. > > Hopefully one day I will make it across the pond and would more than happy to > treat the both of you, and your significant others, to a night out of > drinking and eating and story telling until the sun rises in the East (even if only > known by the fog and grey sky getting lighter). > > Mike Duane A207 > Redding, California > XS Conventional Gear > > > Do Not Archive > > > -- > Checked by AVG Free Edition. > > ________________________________ Message 24 ____________________________________ Time: 09:21:16 PM PST US From: "JR(Bob) Gowing" Subject: Re: Europa-List: europa flyer #46 (sep 05) --> Europa-List message posted by: "JR(Bob) Gowing" Well said Rowland JR (Bob) Gowing 327 in Oz do not archive ----- Original Message ----- From: "Rowland Carson" Subject: Europa-List: europa flyer #46 (sep 05) > --> Europa-List message posted by: Rowland Carson > > No doubt many Europa Club members will by now be wondering what's > happened to the next issue of the Club newsletter. > > As you know, all the jobs in the Club are done without pay by > volunteers, in whatever time they can spare from the day job, the > family, and Europa building/flying. > > Our Editor Peter Grant has suffered multiple setbacks to producing > the September 2005 issue of The Europa Flyer (#46). His computer had > a bad case of dead disc disease (yes, he's had the lecture about > backups) which affected his work as well as the Club stuff. When he > recovered from that his job has taken him abroad, and the firm which > does our printing is closed for a staff holiday at the crucial > moment. Peter has asked me to pass on his apologies to the list. > > So, EF #46 is still in production; it will get to you as soon as our > resources permit. Please be patient - the impatient ones can start to > form a queue for taking over the Editorship at the next AGM, or > indeed sooner, depending on how impatient they are! > > regards > > Rowland > -- info! > > > -- > Checked by AVG Free Edition. > >