Don't know if I have anything to add. N81JM has always had a pair of short thin steel springs ending in an aluminum wheel bracket. Originally she had a hard rubber wheel that soon wore out. After several tries, I settled on a skateboard wheel which lasts about a decade (I'm on my third). This steers well with little desire to ground loop. Unfortunately the whole thing is a wornout rusty mess. Because my CG is too far aft, I'm thinking of using titanium. Is this a bad idea?
On Sun, Feb 10, 2019, 11:42 AM Mark Langford via KRnet <krnet@list.krnet.org wrote: > Brad wrote: > > > Since tailwheel springs are in discussion at the moment, has anyone > made a tailwheel spring out if aluminium bar and if so - > > 1. What spec was used? > > 2. Could it be formed e.g. 20° and if so, must it be formed before > any type if straightening treatment(if relevant)? > > 3. I assume it could be drilled, cut once formed? > > 4. Any ideas what length, thickness for a 900lb KR-2 is advisable? > > I made a spring a few years ago, using a 2" wide x 3/8" thick piece of > 2024 (or maybe it was 7075) which is pretty stiff compared to 6061. > Although it's only about 15" long, it sagged too much to support the > tail with the pilot seated. So I used it as a form for a carbon fiber > one that's maybe 7/16" thick, and it was also too floppy. So I stuck > the two together (out of expediency) and it worked pretty well, but > didn't take long to delaminate between the two. It still works OK, but > I need to wrap it with some BID to hold it together....one of the many > things on my list that I need to do. I can tell you that it was almost > beyond my physical capability to bend the aluminum (using bar clamps, > hangar beam, and a long extension bar), but with a press brake, it's > certainly doable. > > I also use the Aviation Products tailwheel, which requires a leaf > spring to bolt to it. More on that is at > http://www.n56ml.com/kgear.html, if you haven't seen it. Really, > there's no substitute for a steel leaf spring, which is what I have on > the KR2S. It's just a lot heavier than carbon fiber or aluminum, if aft > CG is already a concern. I've also seen a lot of early KRs with a short > little (and much thinner) steel spring that almost looks like a "tab" > hanging 3 or 4 inches aft of the tail spring block. Not much spring to > it, but apparently it works enough to remain in place for decades on > these old planes, and dirt simple, and very light. One downside is you > lose tailwheel authority due to the much shorter moment arm to the main > gear. > > Hope this helps.... > > Mark Langford > m...@n56ml.com > http://www.n56ml.com > > > _______________________________________________ > Search the KRnet Archives at > https://www.mail-archive.com/krnet@list.krnet.org/. > Please see LIST RULES and KRnet info at http://www.krnet.org/info.html. > see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change > options. > To UNsubscribe from KRnet, send a message to krnet-le...@list.krnet.org > _______________________________________________ Search the KRnet Archives at https://www.mail-archive.com/krnet@list.krnet.org/. Please see LIST RULES and KRnet info at http://www.krnet.org/info.html. see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change options. To UNsubscribe from KRnet, send a message to krnet-le...@list.krnet.org
