Tail brace rods.

[Robert Lees]

Re: Tail brace rods.

Aaron:

I have a collection of nipples and jam nuts to do a Taylorcraft or two. The Univair wires have the same thread form, so these would fit. I also have a few straps (brackets...is that what you mean?), but probably not enough to do one Taylorcraft...but it would be a start for you.

If you can work out what you need, let me know.

[t30mg]

Re: Tail brace rods.

The univair link is just what I needed! Thanks.
I guess the brackets are gone too. Can those also be bought?

Hank, what is the spacer at the front bolt of the tail spring? This also was not on our plane when we picked it up.

Thanks for the help....

Aaron

[Hank Jarrett]

Re: Tail brace rods.

I am pretty sure if you check the archives you will find that the wires DO have cut threads. I AM an engineer with a structures background and if I remember correctly I thought the threads were rolled too. There was a lot of discussion on the "rolled" or cut threads several years ago. I am pretty sure Forrest was the one who set me straight. Rolled threads are stronger, but they were probably not cost effective originally so Taylorcraft just went to larger diameter and cut threads.

I haven't looked at the tail wire threads for a long time but the easy way to tell cut from rolled is to just measure the diameter or the wires. When you roll threads you upset the metal. The OD of the thread gets larger and the ID gets smaller (the correct term is actually Major Thread Diameter and Minor Thread Diameter). Just measure the diameter at the threads and on the shank right next to them. Threads larger than the wire, they are rolled. With cut threads you actually remove metal that causes stress concentrations at the bottom of the threads where the wire is more likely to break. If the thread diameter is the same or smaller than the wire, they are cut. There is nothing wrong with either one if they are sized right.

The most important part is that you should NOT make your own wires. They are available from several manufacturers. We really aren't supposed to be making owner produced parts when they can be bought as legal parts from aftermarket suppliers.

I bought new wires for the 41 (the wires are different lengths for different years, ORDER THE RIGHT ONES!) because even though I could get them made (cut or rolled) I wanted yellow tagged parts for something that could cause a tail surface to fold up if it broke. I don't want to die in order to save a few bucks.

If my Taylorcraft logo on my compass fails it isn't going to kill me. If I was doing an STC for new tail wires I would use rolled threads and make them from stainless steel. It's more expensive, but a lot safer. The wires would have to be re-sized to maintain the original safety margins, but that isn't a big deal. The idea of cut threads on a critical, regular steel wire, that is under the tail where it rusts and pits kind of scares me. How often do YOU check the lower tail wires on YOUR pre-flight? I check mine before every flight, but I'm anal. Do you even have your A&P take them off and inspect the threads bases for pits on the annual with a magnifying glass? Yea, I do. That is where they will break, UNDER THE NUT where you can't see it! Don't forget YOU ARE NOT ALLOWED TO PUT THE WIRES BACK ON!!! I do it as part of an ANNUAL and my IA checks that I did it right. The Feds frown on you taking the wires off your tail.

This is one of those things we need to add to our recommended inspection list. We don't need to loose someone or have the FAA to ground all of us because of a tail failure from a corroded tail wire failing. Go look at your wires!

By the way, my new wires came with a conversion coating and I primed and painted them prior to putting them on. The old ones aere just conversion coated with NO PAINT!!!! After rigging them, WITH THE JAM NUTS!! (Can't tell you how many planes don't have the jam nuts) and yes, I couldn't find jam nuts for my wires and bought them from someone in the tribe. The jam nuts aren't going to kill you if they fail and were NOT available. Besides, remember, I look at the wires every pre-flight. After the rigging was finished I used a small brush to paint the fittings and threads to protect the metal exposed by the fittings and jam nuts removing the paint. It's pretty easy to see cracks in the paint.

My suggestions,
Visually inspect your wires NOW! THE jam nuts are REQUIRED!!!
BUY NEW WIRES if yours have ANY corrosion damage
Check the threads at the next annual
Protect them with good corrosion prevention
If there is any doubt, BUY NEW ONES
DON'T just go out and do any removal or rigging without getting your A&P! He is neded to put the jam nuts on, unless you know a way to put them on without removing the wires.

While you are back there take a real close look at your tail wheel. Leaf springs in the right configuration? Spacer tube in place in the fuselage at the front bolt? Steering springs hooked up right? Tail tire in good shape? Everything tight and secure? How about those lower longerons? Good time to poke around with a screw driver for rust in the "Taylorcraft Terrible Triangle".

See, told you I was anal.

Hank

Hank

It's winter, good time to put hands on our babies and make sure they are ready for spring.

Hank

[Robert Lees]

Re: Tail brace rods.

Univair have them: Link

[VictorBravo]

Re: Tail brace rods.

Well, we have the paint on the fuse and tail. Looking through the parts, I've found the tail brace rods are missing.

Any extras out there?

Anybody made their own and have the specs on them?

Thanks.....
Aaron

I would not be afraid at all to have them made. You must use rolled threads, as mentioned by DJ. However, there are companies that roll threads... it's not THAT rare to find. Get yourself some steel rod of the right diameter, and have the threads rolled. This is a PERFECT venue for an "owner produced part" where the owner "manages" the production by an outside vendor. It's legal and it is just exactly the correct example for this rule.

I would guess the rods were originally mild steel, but perhaps this is also a good time to substitute 4130 because of toughness. This is a question for an engineer, but I SUSPECT that stainless would be plenty strong and eliminate the corrosion problem most of us have with tail brace rods.

[N74DV]

Re: Tail brace rods.

Anybody made their own

Not likely and if anyone has made their own I'd be leery of flying in the aircraft. Not many can make proper flying/tail brace wires because they require rolled threads (not die cut threads). Don't be tempted to cut threads on steel wire. Have the threads rolled (expensive) or use braided cable with swaged or nicopress ends (along with proper paperwork of course).

[t30mg]

Well, we have the paint on the fuse and tail. Looking through the parts, I've found the tail brace rods are missing.

Any extras out there?

Anybody made their own and have the specs on them?

Thanks.....
Aaron