Thorp Air Command - T18.net

I have always had a little play on the right side, none on the left. I am wondering if there is an acceptable limit? And measured where.

Thanks

My stab started out with ZERO play and as it got a few hours I noticed a slight play during pre-flight . Not much...you could just feel it . Got out the wrenches and put about a 1/8 turn on the pivot bolt-nut/bushing and now have no play . May have been the primer I sprayed on the fittings during the painting phase and didn't remove on assembly and just wore off causing the play ?

RB

I've checked several A/C at various fly ins and found zero play up to about 3/8" ? Did not measure it just a ball park/eye ball measurement . I have not seen any "published" limit on the play for the stab (could be wrong here), just the amount of play for the S-18 wings . I did hear at one fly in that up to 1/4" is acceptable for the stab . That seems excessive to me . I would measure the play at the tip .

RB

Zero play and no more than 1/8". The bushing is the bearing and not the BOLT, the bolt should be tight. Bob and I worked on a Thorp a few months ago and found the bolts were loose and the stab had 3/16" play. Tightened the bolts and the play went away.

This is not a flutter problem. End play is expected as bushings wear. It's more a matter of your comfort level. Mine have about 3/16 at the tip.
Cubes

I think the bottom line question is...what are the "advertised" limits for the play ? I know what mine are ( zero to about 1/8") and "flutter" was never a concern . Best case... git in there and tighten the nut and bolt and see if that puts a rope around the the beast and reduces the play . It may not have been torqued down correctly in the first place ... per Bill Williams post. Could be a lack of "lube" and accelerated wear . Worse case put in a new bushing and bolt . We all get old and sag with age ! Bada Bing, Bada Boom !

RB

I asked this question to Mike Archer. He remembers reading something about 1/8th inch at the tip. It sure feels like more.