Pro tip: I picked a 4-jaw chuck over a collet block for a weird one-off job and it saved the day

Had a part last week that needed two flats milled 90 degrees apart on a round bar. The print called for a tight tolerance, plus or minus half a thou. I could have set it up in the mill vise with a 5C collet block, but the bar was too long and would have needed extra support. I went with the 4-jaw on the rotary table instead. Took about 20 minutes to dial in, but I got perfect concentricity and held the length without any whip. Sometimes the old-school method is just more solid for weird geometry. Anyone else run into a job where the 'slower' setup was actually the right call?

2 comments

2 Comments

kellyj235d ago

Ever try that with a 3-jaw chuck instead?

ray2105d ago

Three-jaw chucks can work @kellyj23, but you'll need to shim the thin parts to avoid crushing them. Gets the job done in a pinch though.