Pietenpol-List: landing gear springs/was weight loss program
Posted: Thu Oct 23, 2003 5:22 pm
Original Posted By: "w b evans"
Barry asked:>What is the part # you decided on from McMaster Carr? Is it the white>with a yellow stripe?And Terry replied:>the following die spring part number based on some eyeball engineering.>The max compression travel for our gear (per Hatz CB-1 plans) is>approx. 2.5 inches. So we thought the spring rate 392 lb/in should be >about right.>It seems very stiff, but the proof will be in the completed pudding. It>was bare steel, not painted.Take a look at the second (or the last) picture at http://www.flysquirrel.net/cowling/cowling.html which is my little "Flying Squirrel" just sitting on its gear. The landing gear shock strut springs in the picture are at least 3/4 compressed and this is just the fuselage and engine, sans wings, tail group, instruments, and a whole bunch of other stuff. The Squirrel grosses 800 lbs. at design. Anyway, the white springs with blue stripe supposedly provide 264 lb./in. and 460 lbs. at full deflection (McMaster-Carr #9297K84) and that ain't gonna be enough! So I now have heavier ones, I think they are black with a bronze stripe (McM-C #9588K3). They feel really stiff, but like Terry says, the proff will be in the pudding and "too stiff" might not be stiff enough.Oscar ZunigaSan Antonio, TXmailto: taildrags(at)hotmail.comwebsite at http://www.flysquirrel.netConcerned that messages may bounce because your Hotmail account has exceeded ________________________________________________________________________________
Barry asked:>What is the part # you decided on from McMaster Carr? Is it the white>with a yellow stripe?And Terry replied:>the following die spring part number based on some eyeball engineering.>The max compression travel for our gear (per Hatz CB-1 plans) is>approx. 2.5 inches. So we thought the spring rate 392 lb/in should be >about right.>It seems very stiff, but the proof will be in the completed pudding. It>was bare steel, not painted.Take a look at the second (or the last) picture at http://www.flysquirrel.net/cowling/cowling.html which is my little "Flying Squirrel" just sitting on its gear. The landing gear shock strut springs in the picture are at least 3/4 compressed and this is just the fuselage and engine, sans wings, tail group, instruments, and a whole bunch of other stuff. The Squirrel grosses 800 lbs. at design. Anyway, the white springs with blue stripe supposedly provide 264 lb./in. and 460 lbs. at full deflection (McMaster-Carr #9297K84) and that ain't gonna be enough! So I now have heavier ones, I think they are black with a bronze stripe (McM-C #9588K3). They feel really stiff, but like Terry says, the proff will be in the pudding and "too stiff" might not be stiff enough.Oscar ZunigaSan Antonio, TXmailto: taildrags(at)hotmail.comwebsite at http://www.flysquirrel.netConcerned that messages may bounce because your Hotmail account has exceeded ________________________________________________________________________________