Vent: Lost a $1200 fixture last month because of a bad clamp

Last month at the shop in Dayton, I had a 5-axis job running and one of the pneumatic clamps didn't fully engage. The part shifted during a roughing pass and the whole fixture was toast. Cost us a day of downtime and $1200 for a replacement. Anyone else had a clamp fail without warning?

3 comments

3 Comments

willowg881mo ago

You say "the whole fixture was toast" but honestly, $1200 sounds like a pretty cheap lesson for a 5 axis job. I've seen guys blow way more than that on tooling just because they forgot to check a collet. Clamps fail all the time, it's just part of the job. If you're running production and not double checking your workholding before every cycle, you're basically asking for trouble. Downtime sucks but a day isn't that bad compared to what could have happened if that part flew out at 10k rpm. Maybe your shop needs better pre run checks instead of blaming the hardware.

gibson.morgan1mo ago

Wait, did you read that article in Modern Machine Shop last month about the guy who ran a $20k titanium part at 15k rpm with a vise that was only tightened by hand? Because that's exactly what this reminds me of. Your point about pre run checks is spot on, but I think people also forget that even good clamps can fail if you're not paying attention to chip buildup or coolant messing with the grip. I've seen operators walk away from a machine for two hours and come back to find a part shifted because a clamp got loose from vibration. It's not always the hardware's fault, sometimes it's just the nature of doing this stuff day in and day out. A day of downtime is frustrating but like you said, it beats having a part fly out and take out the whole spindle or worse, someone's face.

martin.riley1mo ago

Dude that reminds me of the time I saw a guy try to clamp a part with a Harbor Freight C-clamp on a Bridgeport. It held for like 30 seconds before the part launched across the shop and took out the sprinkler system.