miller tig twist nobs

[tomb]

Hi all I'm having problems with some "twisty nobs" on my miller tig . They adjust the voltage etc. They have a set no. of revolutions and then click at the end of adjustment. The prob is they have no adjustment just clicks, I think they are dirty. I've tried contact cleaner but to no avail. Any ideas or do you think I need new nobs? Its not to sound dodgy !!! Googled "twist knobs" but got some random results. Any ideas?

 

[pedrobedro]

Rotary switch might get you a hit. There are some that keep turning after they reach maximum and come back down when reversed from wherever you stop

 

[the snooper]

if they dont actually work any more take them apart and have a look inside you may be able to repair them