Compresion Strut

[ricky]

Good even I like to get some info,I rebuilt one wing an only notice one spacer on each side of compresion tube for one of my t-craft,now im doing a another wing,useing a new wing that got damage by tree,as I remove compresion tube
saw 3 alum spacer one on rear an two on front spar,this ok or not.

Rick

[lawheelock]

Re: Compresion Strut

Rick,
The critical dimension is the spacing between the front and rear spar centerlines which must be the same as the spacing between the centers of the fuselage mounting brackets. The aluminum shims are used as needed to keep the wing square and proper spacing between spars. There was probably variability in the finished length of the compression members and shims were used to maintain the proper spacing.
Larry Wheelock, A&P/IA repairing a BC12D wing with a new rear spar.

[Buell Powell]

Re: Compresion Strut

Rick,
Just wanted to add something to what Larry posted in case you haven't rebuilt Taylorcraft wings before.One thing you might want to be sure about if you haven't already noticed, the compression struts aren't all the same length. On the pre-wars and some post wars there are 3 different lengths. The one by the strut attach fitting and at the butts ends are shorter (and not by the same amount) to allow for the doublers.

If I remember correctly the ones on the F19's used the same ones as the one by the attach fittings except for the butt rib and shimmed the rest. The strut by the attach fitting is only slightly shorter and someone may not have noticed and used it in the wrong location and used more shims to make up the difference.

Checking the tram might be a way to see about that. I would recommend fitting the wings to the fuselage before covering just to make sure the the fittings line up. I always fit the ailerons to the wings before covering too-especially to make sure the brackets line up and the clearance between the wing and aileron is acceptable-it's easy to correct then but not after they are covered.

Hope this helps.
Buell

[Robert Lees]

Re: Compresion Strut

Hello Ricky,

What you are dealing with is "Trammeling". This means making sure that the two spars on a wing are parallel and square to the fuselage. Try entering Trammeling into the search box, there is a wealth of information there.


Because no two wings are EXACTLY alike, the factory allowed some shims between the compression struts. So some compression struts will have none, 1, 2 or 3 shims.

Hope that helps,
Rob

[ricky]

Re: Compresion Strut

Thank guy as caution I number the compres tube an there proper location,thank you t-craft for your info an wisdom,

Rick

[ricky]

Re: Compresion Strut

Thank guy as caution I number the compres tube an there proper location,thank you t-craft for your info an wisdom,

Rick