Here are the pix of my finger-tip tig controller. Nothing fancy – just started with a couple chunks of aluminum, and whittled until I liked the size and feel.
 

Some design notes: 

 

The wheel is slightly larger than the width of the box, so that it sticks out enough on the top and sides to be manipulated by a gloved hand.The pot has an 1/8" shaft, the end of which rides in the bore that is visible on the front of the unit. The tap for the mounting thread for the pot had to go through the hole where the cable clamp is mounted - I almost didn't think of that in time ;-)

The switch is a snap-action microswitch-type; not absolutely necessary, but it has a nice feel.

The control cable is shielded, and there are ferrite beads and shunt capacitors on all leads.


George Dubovsky