Push/Pull Knob Question

[howelldw]

Hello!

I'm doing some panel work and had a question;

Are the push-pull knobs threaded? Can I unscrew them or are they pressed on or otherwise?

I wanted to remove the back panel and redo it. I just didn't want to damage the knobs getting them off.

[brianm]

If the the push-pull controls are original, they have a barbed shank that was heated and pressed into the knobs. If they are aftermarket, then who knows. The knob can be removed by heating the shank again, but I wouldn't do it with the cable installed in the airplane.

You will probably need to remove the whole control, not just the knob, to get the acrylic overlay off. The hole for the control is 3/8", but there is a 1/2" diameter flange. On my original acrylic, the 3/8" hole had a 1/2" diameter by 1/16" deep counterbore so the flange sat flush.