Swapped out my collet chuck for a shrink fit holder on a tight tolerance job

I've been running CNC mills for about 4 years now, and I always thought collet chucks were good enough for everything. But last month I had a job for a medical device part in Cleveland where the tolerance was +/- 0.0005 inches on a 1/4 end mill. My collet chuck was giving me maybe 0.001 runout after a few tool changes, and I kept scrapping parts. The guy at the tool supply shop in Akron talked me into trying a shrink fit holder for $180. Honestly, I thought it was overkill for my little Haas VF-2. First part I ran with it came out perfect at 0.0002 runout, and I finished the 200-piece run with zero scrap. Now I'm kicking myself for not switching sooner. Has anyone else had a similar experience where a simple tooling change saved your whole production run?

3 comments

3 Comments

danielm803d ago

$180 for a shrink fit holder? That's crazy cheap, every one I've priced was double that at least. Were you running that job dry or with coolant?

fionafoster3d agoTop Commenter

$180 for a shrink fit holder" is a steal, but @danielm80 I see it differently because I think the real win was the zero scrap on a medical job. Saving 200 parts makes that cost nothing in the long run.

alice_allen53d ago

Wait @fionafoster, have you been using shrink fit holders for long? I totally agree with you on the scrap savings part. That $180 pays for itself the second you don't have to re-cut a $50 medical part. I've never used one myself, but stories like this make me want to try one on my tight clearance holes. Maybe I should just pony up the cash and stop being cheap.