Twin 4J chuck keys

[petertha]

I made a pair of identical chuck keys specifically for setting up my 4-jaw chuck. Not my idea, I saw it somewhere. But it works quite well because you can adjust the opposing jaws simultaneously in unison while watching the dial, converging on the target with both jaws tight. Its easier to do than explain but saved me set dial-in time because normally I am slow as a tortoise.

I found a piece of 0.750" diameter mystery metal which looked nice & shiny - always a dangerous sign It wasn't magnetic so I knew it was some kind of stainless. Not the most fun to machine but oh well, used up the scrap & it wont rust -LOL. Initially I was going to make a knob but didn't like how it looked so went the tommy bar route. Notice my goof up, the tommy bar is not aligned to the square facets. Oops. Then I looked at my other commercial chuck keys - neither are they! Haha. So its a design enhancement, not a screw up.