---------------------------------------------------------- Kolb-List Digest Archive --- Total Messages Posted Mon 05/08/17: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 11:51 AM - Tailwheel Strut (Bill Berle) 2. 03:53 PM - Re: Tailwheel Strut (George Helton) 3. 04:12 PM - Re: Tailwheel Strut (Bill Berle) 4. 04:58 PM - Re: Tailwheel Strut (Charlie England) ________________________________ Message 1 _____________________________________ Time: 11:51:50 AM PST US From: Bill Berle Subject: Kolb-List: Tailwheel Strut And yet another technical question for the experienced Kolbers... I have seen messages on the list about the use of several different materials for the tailwheel "stinger" spring. I believe I've seen posts about fiberglass, steel, and aluminum having been tried. My Firestar has a tailwheel spring that may be fiberglass. There are no visible fasteners (bolts, rivets, etc) holding it into either the fuselage sub-fin or the tailwheel unit. I recently read that some of the springs were fiberglass rods that were glued in with epoxy instead of bolted. From what I have read, the fiberglass is not the best choice. So if mine is fiberglass, I'm guessing I should replace it. So now... this big question! Does anyone on the Kolb list know if it is more or less desirable to use 7075-T6 aluminum, or 4130 / 4340 steel, or some other material, based on weight versus durability versus shock absorption? The reason I am asking this is that I have a good piece of 7075-T6 material available (the old original Kolb aluminum gear leg that I removed). This material is used on a very large number of aircraft landing gear legs, both FAA certified and experimental. It is the preferred material used by the #1 manufacturer of aircraft landing gear in the world (Grove Aircraft). What is the consensus among the experienced Kolbers about 7075-T6 used for the tail spring? Does it work well... does it break... is it the best balance between weight and strength... have all the people who used 7075 broken them and replaced them with steel???? Bill Berle www.ezflaphandle.com - safety & performance upgrade for light aircraft www.grantstar.net - winning proposals for non-profit and for-profit entities ________________________________ Message 2 _____________________________________ Time: 03:53:02 PM PST US From: George Helton Subject: Re: Kolb-List: Tailwheel Strut Well Bill, it is really a matter of personal preference. I haven't had a lot luck with the original fiberglass rod. I had two fail. Both failed in the trailer sitting static. Go figure. I've gone with new Kolb 7075-T5 rod and new breakaway tailwheel assembly on my original Firestar it's a nice setup. Using a old landing gear leg would require a lot of machining I would think? But if you've got that kind of equipment I guess that is an option. I know some guys like to use a heat treated 4130 steel tube. I went with the aluminum only because I'd personally rather bend the rod before possibly damaging the rudder post and its weldments. Anyway, that's all my thoughts. I'm sure there are people on here with theirs too. George H. Firestar 1 #FS100 14GDH gdhelton@gmail.com Mesick, Michigan Have a great day! > On May 8, 2017, at 2:51 PM, Bill Berle wrote: > > > And yet another technical question for the experienced Kolbers... > > I have seen messages on the list about the use of several different materials for the tailwheel "stinger" spring. I believe I've seen posts about fiberglass, steel, and aluminum having been tried. > > My Firestar has a tailwheel spring that may be fiberglass. There are no visible fasteners (bolts, rivets, etc) holding it into either the fuselage sub-fin or the tailwheel unit. I recently read that some of the springs were fiberglass rods that were glued in with epoxy instead of bolted. From what I have read, the fiberglass is not the best choice. So if mine is fiberglass, I'm guessing I should replace it. > > So now... this big question! Does anyone on the Kolb list know if it is more or less desirable to use 7075-T6 aluminum, or 4130 / 4340 steel, or some other material, based on weight versus durability versus shock absorption? > > The reason I am asking this is that I have a good piece of 7075-T6 material available (the old original Kolb aluminum gear leg that I removed). This material is used on a very large number of aircraft landing gear legs, both FAA certified and experimental. It is the preferred material used by the #1 manufacturer of aircraft landing gear in the world (Grove Aircraft). > > What is the consensus among the experienced Kolbers about 7075-T6 used for the tail spring? Does it work well... does it break... is it the best balance between weight and strength... have all the people who used 7075 broken them and replaced them with steel???? > > Bill Berle > www.ezflaphandle.com - safety & performance upgrade for light aircraft > www.grantstar.net - winning proposals for non-profit and for-profit entities > > > > ________________________________ Message 3 _____________________________________ Time: 04:12:35 PM PST US From: Bill Berle Subject: Re: Kolb-List: Tailwheel Strut Thanks George, I'm trying to gather a consensus of people's experience with aluminum and steel. I have read about John H's preference for 4130 heat treated steel. I'm trying to get everyone else's opinion to have a fair comparison. I happen to have this chunk of 7075 for free, so if it is a good material then it saves me the time/cost/shipping of buying material. If it is not a good material to use then of course any cost and time savings doesn't mean much. Bill Berle www.ezflaphandle.com - safety & performance upgrade for light aircraft www.grantstar.net - winning proposals for non-profit and for-profit entities -------------------------------------------- On Mon, 5/8/17, George Helton wrote: Subject: Re: Kolb-List: Tailwheel Strut To: kolb-list@matronics.com Date: Monday, May 8, 2017, 3:52 PM Helton Well Bill, it is really a matter of personal preference. I haven't had a lot luck with the original fiberglass rod. I had two fail. Both failed in the trailer sitting static. Go figure. I've gone with new Kolb 7075-T5 rod and new breakaway tailwheel assembly on my original Firestar it's a nice setup. Using a old landing gear leg would require a lot of machining I would think? But if you've got that kind of equipment I guess that is an option. I know some guys like to use a heat treated 4130 steel tube. I went with the aluminum only because I'd personally rather bend the rod before possibly damaging the rudder post and its weldments. Anyway, that's all my thoughts. I'm sure there are people on here with theirs too. George H. Firestar 1 #FS100 14GDH gdhelton@gmail.com Mesick, Michigan Have a great day! > On May 8, 2017, at 2:51 PM, Bill Berle wrote: > > --> Kolb-List message posted by: Bill Berle > > And yet another technical question for the experienced Kolbers... > > I have seen messages on the list about the use of several different materials for the tailwheel "stinger" spring. I believe I've seen posts about fiberglass, steel, and aluminum having been tried. > > My Firestar has a tailwheel spring that may be fiberglass. There are no visible fasteners (bolts, rivets, etc) holding it into either the fuselage sub-fin or the tailwheel unit. I recently read that some of the springs were fiberglass rods that were glued in with epoxy instead of bolted. From what I have read, the fiberglass is not the best choice. So if mine is fiberglass, I'm guessing I should replace it. > > So now... this big question! Does anyone on the Kolb list know if it is more or less desirable to use 7075-T6 aluminum, or 4130 / 4340 steel, or some other material, based on weight versus durability versus shock absorption? > > The reason I am asking this is that I have a good piece of 7075-T6 material available (the old original Kolb aluminum gear leg that I removed). This material is used on a very large number of aircraft landing gear legs, both FAA certified and experimental. It is the preferred material used by the #1 manufacturer of aircraft landing gear in the world (Grove Aircraft). > > What is the consensus among the experienced Kolbers about 7075-T6 used for the tail spring? Does it work well... does it break... is it the best balance between weight and strength... have all the people who used 7075 broken them and replaced them with steel???? > > Bill Berle > www.ezflaphandle.com - safety & performance upgrade for light aircraft > www.grantstar.net - winning proposals for non-profit and for-profit entities > > > > The Kolb-List Email Forum - Navigator to browse List Un/Subscription, 7-Day Browse, Chat, FAQ, - MATRONICS WEB FORUMS - via the Web Forums! - NEW MATRONICS LIST WIKI - Email List Wiki! - List Contribution Web Site - support! -Matt Dralle, List Admin. ________________________________ Message 4 _____________________________________ Time: 04:58:15 PM PST US Subject: Re: Kolb-List: Tailwheel Strut From: Charlie England For another data point, the original Twinstar I'm restoring appears to have a fiberglass tailspring. It's s/n22, 1st registered in 1985. No idea on how many hours are on it, but the guy I bought it from has always flown a lot, so it likely has quite a few hours. It doesn't appear to have any sag, and it's standing up fine so far for me, but I'm just rolling the bare fuselage around the shop right now. :-) Charlie On 5/8/2017 6:12 PM, Bill Berle wrote: > > Thanks George, I'm trying to gather a consensus of people's experience with aluminum and steel. I have read about John H's preference for 4130 heat treated steel. I'm trying to get everyone else's opinion to have a fair comparison. > > I happen to have this chunk of 7075 for free, so if it is a good material then it saves me the time/cost/shipping of buying material. If it is not a good material to use then of course any cost and time savings doesn't mean much. > > > Bill Berle > www.ezflaphandle.com - safety & performance upgrade for light aircraft > www.grantstar.net - winning proposals for non-profit and for-profit entities > > -------------------------------------------- > On Mon, 5/8/17, George Helton wrote: > > Subject: Re: Kolb-List: Tailwheel Strut > To: kolb-list@matronics.com > Date: Monday, May 8, 2017, 3:52 PM > > Helton > > Well Bill, it is really a matter of > personal preference. I haven't had a lot luck with the > original fiberglass rod. I had two fail. Both failed in the > trailer sitting static. Go figure. I've gone with new Kolb > 7075-T5 rod and new breakaway tailwheel assembly > on my original Firestar it's a nice > setup. Using a old landing gear leg would require a lot of > machining I would think? But if you've got that kind of > equipment I guess that is an option. I know some guys like > to use a heat treated 4130 steel tube. I went with the > aluminum only because I'd personally rather bend the rod > before possibly damaging the rudder post and its weldments. > Anyway, that's all my thoughts. I'm sure there are people on > here with theirs too. > > George H. > Firestar 1 #FS100 > 14GDH > gdhelton@gmail.com > Mesick, Michigan > > > Have a great day! > > > On May 8, 2017, at 2:51 PM, Bill > Berle > wrote: > > > > --> Kolb-List message posted > by: Bill Berle > > > > And yet another technical question > for the experienced Kolbers... > > > > I have seen messages on the list > about the use of several different materials for the > tailwheel "stinger" spring. I believe I've seen posts about > fiberglass, steel, and aluminum having been tried. > > > > My Firestar has a tailwheel spring > that may be fiberglass. There are no visible fasteners > (bolts, rivets, etc) holding it into either the fuselage > sub-fin or the tailwheel unit. I recently read that some of > the springs were fiberglass rods that were glued in with > epoxy instead of bolted. From what I have read, the > fiberglass is not the best choice. So if mine is fiberglass, > I'm guessing I should replace it. > > > > So now... this big question! Does > anyone on the Kolb list know if it is more or less desirable > to use 7075-T6 aluminum, or 4130 / 4340 steel, or some other > material, based on weight versus durability versus shock > absorption? > > > > The reason I am asking this is > that I have a good piece of 7075-T6 material available (the > old original Kolb aluminum gear leg that I removed). This > material is used on a very large number of aircraft landing > gear legs, both FAA certified and experimental. It is the > preferred material used by the #1 manufacturer of aircraft > landing gear in the world (Grove Aircraft). > > > > What is the consensus among the > experienced Kolbers about 7075-T6 used for the tail spring? > Does it work well... does it break... is it the best balance > between weight and strength... have all the people who used > 7075 broken them and replaced them with steel???? > > > > Bill Berle --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message kolb-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Kolb-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/kolb-list Browse Digests http://www.matronics.com/digest/kolb-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.