Taylorcraft/Martin wire

[3Dreaming]

Re: Taylorcraft/Martin wire

When I got my first t-craft in 1968 it was a 1939 BL-65 basket case and along with the paperwork that came with it was "service bulletin" or something like that from Taylorcraft or perhaps the CAA that required the ribs to be stitched because the had not been at the factory and the upper surface fabric had been ballooning up.

Sort of humorous IMHO.

Dave

I believe that the SB was for stiching the aileron ribs.

[Guest]

Re: Taylorcraft/Martin wire

Hah!

I am thinking that my memory may be the humorous thing! LOL

Thanks Tom.

Dave

[astjp2]

Re: Taylorcraft/Martin wire

Dave, the 39 was a truss rib, the 48 would is stamped. It would have needed to be stitched. Tim

[Guest]

Re: Taylorcraft/Martin wire

Tim, yes I agree, the bulletin was requiring stitching as compared to noting at all. As Tom point out that perhaps it was only for the aileron. That may be true. 1968 was along time ago. I am sure that there was bulletin requiring stitch versus having no attachment but I can't be sure if it was the whole wing or aileron only. I do recall the discussion about the fabric lifting up and needing an attachment method.

Dave

[Hank Jarrett]

Re: Taylorcraft/Martin wire

Only the stamped rib wings used the wire. ALL of the stick rib, pre-war wings always were rib stitched.

Hank

[cvavon]

Re: Taylorcraft/Martin wire

Was digging threw some paper work for my plane and ran across this letter from the factory about rib stitching.

[Mark Bowden]

Re: Taylorcraft/Martin wire

Sorry to be away from this for a bit.

Mike, that was an extremely valuable drawing you posted. Thank you very much. It is important because it shows how the features are located, what's important and how tolerances on the part are to be held.

Notice that the contact surface area of the wire under the rib which holds everything on is only 0.016" long, +.004, -.005.

It has been a challenge to get a drawing made from measuring the wire that was sent to me by Chuck because the features are so fine. However the Aeronca drawing has really helped get to a point to start a reasonable discussion with a bender.

It also shows the original material was music wire. It gives an alternate callout for an out of date stainless code of which 302 was part of.

Notice the Martin wire shape. There no "under rib" engagement feature, only a tangent of an arc.

We think at this point the engagment flat on the Tcraft part is 0.014"

[Mark Bowden]

Re: Taylorcraft/Martin wire

Does anyone have access to a rib? I would really like to get a thickness measurement of the rib material thickness. I need it to help confirm the bend feature that goes around the rib, fabric and fabric under the wire.

This bend in the Tcraft wire at this point is strange, it has compound curve portion.

Thanks, Mark

added: I can't measure one because I have riveted truss ribs.

[3Dreaming]

Re: Taylorcraft/Martin wire

It is hard to get a good measurement, because all the edges are rolled or flanged. That being said my calipers say .020. The fabric will just be a few thousandths thick. The reinforcing tape maybe .020-.030, but this is just a guess.

[Guest]

Re: Taylorcraft/Martin wire

Does anyone have access to a rib? I would really like to get a thickness measurement of the rib material thickness. I need it to help confirm the bend feature that goes around the rib, fabric and fabric under the wire.

This bend in the Tcraft wire at this point is strange, it has compound curve portion.

Thanks, Mark

added: I can't measure one because I have riveted truss ribs.

I have some ribs.

Tell me what to measure.

Dave

[Mark Bowden]

Re: Taylorcraft/Martin wire

Thanks guys, just check the material thickness where it is easy to do please with caliper or mic. Then if possible, please measure the full thickness of the rib flange from the outer or loft side of the rib to the inside feature that would include any formed feature for the wire.

Thanks, Mark

[Guest]

Re: Taylorcraft/Martin wire

Hi Mark,

I don't follow that description.

Will be happy to measure for you but I only understand the thickness part of the request.

I could post a picture of a rib in particular the portion around a hole and then we could go form there.

Maybe that will help.

I am at 919 365 3063 if you want to call.

Dave

[Guest]

Re: Taylorcraft/Martin wire

Mark,

Here are the measurements we talked about.

.023" rib thickness
.158" wire hole i.d. (5/32"?)
.009"-.010" cloth reinforcing tape thickness (modern tape may be different, will check, I have some)
.026" rib flange trench depth
3.011" wire hole to wire hole distance

Dave

[Ragwing nut]

Re: Taylorcraft/Martin wire

Mark,

Here are the measurements we talked about.

.023" rib thickness
.158" wire hole i.d. (5/32"?)
.009"-.010" cloth reinforcing tape thickness (modern tape may be different, will check, I have some)
.026" rib flange trench depth
3.011" wire hole to wire hole distance

Dave

poly fiber reinforcing tape is much thicker than you have listed. Its probably closer to .025-.035 thick.

[Mark Bowden]

Re: Taylorcraft/Martin wire

Quick update. The vendor here in KC could not do it due to the limitations on their machine clearance. Started with them as they were in town. Will be on to the next 10-20 vendors or so that are in close in the midwest. Will know more next week.