Pietenpol-List: trim adjustment update
Posted: Mon Dec 05, 2005 10:16 am
Original Posted By: Jim Markle
For anyone who is interested, I've fabricated and tried out an elevator trim mechanism (simple) using bead chain. The idea is that you pull the chain out to where the elevator is trimmed, then drop the chain into a notch to hold it there. The chain applies tension to a bungee that pulls on the elevator bellcrank in the tailcone.My findings: the bead chain I got from the hardware store is only good for about 12 lbs. pull, and the small chain "joiners" let go at even less than that... 8 lbs. Readings were taken with a "fish de-liar" type scale. The bungee sure makes a loud twang when the chain lets go ;o) Conclusion: abandon the bead chain since I can't find anything more robust. I'll be trying nylon parachute cord with knots tied in it, or something similar. I've found that it takes a couple of pounds' pull just to hold the weight of the elevator, with no air loads imposed.In lieu of cord with knots, I could do an aluminum bar with notches cut in it and may try that, too.Oscar ZunigaSan Antonio, TXmailto: taildrags(at)hotmail.comwebsite at http://www.flysquirrel.net________________________________________________________________________________Date: Mon, 5 Dec 2005 11:04:21 -0600 (GMT-06:00)
For anyone who is interested, I've fabricated and tried out an elevator trim mechanism (simple) using bead chain. The idea is that you pull the chain out to where the elevator is trimmed, then drop the chain into a notch to hold it there. The chain applies tension to a bungee that pulls on the elevator bellcrank in the tailcone.My findings: the bead chain I got from the hardware store is only good for about 12 lbs. pull, and the small chain "joiners" let go at even less than that... 8 lbs. Readings were taken with a "fish de-liar" type scale. The bungee sure makes a loud twang when the chain lets go ;o) Conclusion: abandon the bead chain since I can't find anything more robust. I'll be trying nylon parachute cord with knots tied in it, or something similar. I've found that it takes a couple of pounds' pull just to hold the weight of the elevator, with no air loads imposed.In lieu of cord with knots, I could do an aluminum bar with notches cut in it and may try that, too.Oscar ZunigaSan Antonio, TXmailto: taildrags(at)hotmail.comwebsite at http://www.flysquirrel.net________________________________________________________________________________Date: Mon, 5 Dec 2005 11:04:21 -0600 (GMT-06:00)