Work Part Clamping (Many Of You Are Doing It Wrong)

Daily I see IG posts, YouTube videos, and post here of the unknown doing unsafe work, and quite frankly, you guys (and some gals) scare me.

Maybe it is because you have not attended my Work Part Clamping 101 Class; well here is Professor Cournoyer’s quick clamping guide.

These CNC machines are capable of creating a lot of force Especially the Shapeoko Spindles (1 plus hp). There is a right way and a lot of wrong ways to clamp your work.

Some simple rules:
(1) The hold down bolt should be close to your part.
(2) The clamp should be level
(3) The clamp should be made from a strong material (preferably metal, and never plywood)
(4) The stud/bold should be at least a grade 5. (STAY away from HD and Lowes, most of their hardware is NOT graded hardware)

Guys, Gals, PLEASE Work Smart, Work Safe.

Feel free to print out this great sketch…there might be a test. (It’s all about the Fulcrum)

This was my first metal project, and I understand that not everyone wants to machine metal. Here is a link from some nice people who sell some small (and strong) clamps.


Thanks for the info Rich :slight_smile:

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Heres a great example of the Dangers of improper workholding:
Also, Dont walk away!
This is so painful to watch, but it needs to be shared.
If Darwins Garage is on the forum, thanks for posting this?!


Holy crap, that’s terrifying.

Wooooow… that’s crazy!

I haven’t been able to get this picture out of my mind since I saw this video, and mostly because I am almost never in my shop when J (That’s her name), is running. I just ordered an Watchdog Automatic Fire Extinguisher for my shop. I’ll sleep better tonight…