bowden cable end

prkaye · #1 10-19-2009, 09:45 AM

My carb heat cable has to have a curve it at the end because the arm travels through an arc as the door opens and closes. See pic. The bowden cable end from vans is secured by a castle nut and cotter pin. It now occurs to me that maybe I should have installed this so that the nut is not torqued down, and the cable end can rotate freely as the door opens and closes, allowing the cable to remain pointed straight.
What have others done?

Beancounter · #2 10-19-2009, 11:48 AM

Phil
I heard stories of the cable breaking after a short time when using that method.

I wrapped the cable around a -4 bolt into a nut plate on the carb heat arm.

scard · #3 10-19-2009, 12:13 PM

After all kinds of pains, here is what I ended up with.

prkaye · #4 10-19-2009, 01:11 PM

But is that bowden cable end designed to rotate freely as I decribed? Allowing it to do so is the only way i can see to get smooth travel of the arm without putting a flexing strain on the cable.

TOAD · #5 10-19-2009, 02:41 PM

It does have to rotate freely. I stack mine up this way.

1) Bolt
2) Single washer for wear
3) Put through the lever
4) Washer for wear -this portion 1-4 rotates freely

5) Cable - there shoud be space between the above stack.
6)Washer - Tight against the cable. THis locks the cable in.
7)Nut - tightens up and locks 5-7.

I drill my own bolts so that I get the exact setup I want without slop.

scard · #6 10-19-2009, 02:52 PM

In my picture, the -3 bolt is fixed solid with a nut on each side of the arm. The cable wire is wrapped around the bolt on which it rotates freely. Way better than the B-nut as far as I'm concerned.

Captain Avgas · #7 10-19-2009, 04:25 PM

Quote:

Originally Posted by prkaye

My carb heat cable has to have a curve it at the end because the arm travels through an arc as the door opens and closes. See pic. The bowden cable end from vans is secured by a castle nut and cotter pin. It now occurs to me that maybe I should have installed this so that the nut is not torqued down, and the cable end can rotate freely as the door opens and closes, allowing the cable to remain pointed straight.
What have others done?

Phil, the elegant solution is probably the B-nut. See photo. The wire is held in place with a grub screw and the entire shaft is free to rotate....no bending or stress on the wire. Available from Aircraft Spruce. If you require extra security for your application you can thread the wire through the shaft hole and then hook the wire back on itself.

prkaye · #8 10-19-2009, 04:53 PM

yes that B nut looks exactly like what i got from Vans. My initial question was whether I should torque down the castle nut, or leave it loose (cotter-pined) so its free to rotate. I have it that way now and it's working great.

TOAD · #9 10-19-2009, 08:57 PM

The bolt in all cases is free to rotate. Think about it some more. The lock on the cable is because the nut holds the cable in the hole drilled in the shoulder of the bolt. The bolt is free to rotate in the control arm. This allows you to adjust the cable at that the bolt. I know you can adjust your wrap with the clamp but this is just another way.

Do what ever you wish, but be careful not to wrap the cable in too tight a radius. It may break. The cable is not all that flexible and might be too brittle to take it. Careful Please! Try a test on the extra cable you cut off. I hate surprises!

sprucemoose · #10 10-20-2009, 01:18 AM

Quote:

Originally Posted by prkaye

My initial question was whether I should torque down the castle nut, or leave it loose (cotter-pined) so its free to rotate. I have it that way now and it's working great.

Phil,

I'm a little confused. Where would you use a castle nut on a bug nut like you have? The shaft should be smooth, not threaded, with a hold for a cotter pin. A washer (actually a spring washer and flat washer combo) and cotter pin will do the trick and allow the bug nut to rotate freely.

Do you have a picture of the other side of the installation?