Trim Tab Cable

[gfortin]

I need to replace my trim tab cable. What size cable should I use 1/16,5/32,or 1/8? I read somewhere they recommend increasing the size from the original. How much should I order? Does it matter if it is galvanized or Stainless? Does anybody have any clever ways of stringing it through the fairleads of a covered fuselage. I was thinking of pulling an unbreakable string through when I take the old cable out. Anyone have a better way? Thanks, in advance for your informed advice. George

[Edwin Otha]

Re: Trim Tab Cable

George,
I've had good luck using heatshrink tubing to secure the new cable to the old one and use the old cable to pull in the new one. It needs to be snug and the longer the better.
EO

[gfortin]

Re: Trim Tab Cable

Thanks, I like that.

[gfortin]

Re: Trim Tab Cable

Is there anyone who can answer my question about the size of the cable?

[Robert Lees]

Re: Trim Tab Cable

I used 3/32 7x19 galvanised cable from Aircraft Spruce (their P/No 05-04000). I didn't use stainless because the small aft trim pulley has a small radius.

If you are replacing the cable, you should consider replacing the trim spring too. I have new stainless shot-peened springs...PM me if you're interested.

Rob

[mikeg]

Re: Trim Tab Cable

The 1946, '45, and '41 that I have restored all had 1/16" diameter trim tab actuating cable. The '40, which has a totaly different system, used solid wires of about .050" diamerter to run the trim wing.
Mikeg
NC29804
NC27451

[gfortin]

Re: Trim Tab Cable

Robert, I received an envelope from the UK today. The envelope had a blank,empty envelope#10 . Mystery? I hope this wasn't supposed to be the trim spring you were sending me. George

[Robert Lees]

Re: Trim Tab Cable

Probably was (why the spring got lost I don't know...both envelopes were sealed...were the envelopes damaged?)

I'll send another.

Rob

[gfortin]

Re: Trim Tab Cable

No, They were not damaged. They were both sealed. Neither of which had any contents. It's a mystery. George

[Robert Lees]

Re: Trim Tab Cable

Another one went in the mail yesterday.

Rob

[mulwyk]

Re: Trim Tab Cable

On the matter of cable size: I used a Lees spring and 1/16" cable with new pulleys. The system works ok I suppose, but seems a little iffy. I can make it slip by holding the cable with one hand and turning the crank with the other hand. I'm going to try putting more tension on the cable/spring and maybe use rosin on the cable, but it seems that a larger diameter cable might get more traction. Next time I'll try 3/32" cable.

[Guest]

Re: Trim Tab Cable

Hi Bob,

Try this;

1) clean the cable make it free of grease/oil use lacquer thinner

2) clean the rear pulley by drawing the edge of a lacquer thinner soaked rag thru the groove to remove all dirt/grease/oil/paralketone from the groove

3) clean the front pulley as above

4) only operate the trim when the wheel is in the neutral position

5) don't worry about making it slip when you hold on cable that is normal

Dave

[mulwyk]

Re: Trim Tab Cable

good point Dave,
Now I can't remember de-greasing the pulleys OR the new cable. That's probably a good part of the problem. Thanks, I try that just as soon as it warms up a bit so I can go out there without freezing my a** off!

[Forrest Barber]

Re: Trim Tab Cable

WE use "binder twine" and solvent to clean front and rear pulleys.... The pulleys really have a "V" groove in them originally to help prevent the slipping action.

[gfortin]

Re: Trim Tab Cable

Thanks, Robert. I will look forward to another UK package with Spring. I ordered Galvanized 3/32 and 1/8 cable from Airparts. They seemed to have the best price. I guess I should clean the pulleys also. Happy Holidays to all and thanks for the info and advice. George