Kopal Milling Clamps

[Jay]

I fully understand how the Kopal clamps work and worked very close with Kopal along with a few work colleagues 19 years ago when we found that although the clamps where good on material with a clean edge they where pretty crap when it came to a flame cut edge or rough edge.
The problem we found was that the foot of the clamp wasn't in full contact with the edge of the plates we where using because they where flame cut so after having a few plates come flying off our HMC (one littereley taking the enclosed doors off the runner and bending the frame) we had talks with Kopal to look in to the problem. After we looked at the job and found what was happening and Kopals rep having seen what was happening the answer we got and only solution was to dog them down as much as possible until all the clamp was in contact with the edge of the plate which worked apart from blowing the heads of the screws out which is where we had to fit collets to the screw head. In all they are pretty good clamps but you have to torque them up more on anything than a good clean edge especially on a HMC.

[magicniner]

In all they are pretty good clamps but you have to torque them up more on anything than a good clean edge especially on a HMC.

It's common in industry to misuse and abuse equipment that is used outside it's design parameters but to describe that as a fault of the equipment rather than operator error is unfair on the product.
The correct solution to your problem would have been custom feet for the clamp noses which incorporated spherical contact surfaces to allow free alignment of a lower section with 3 distinct high points allowing clean 3 point contact on uneven surfaces, the rep sounds like he had no engineering background or problem solving capabilities beyond "big spanners" and when all you have is a hammer, every problem looks like a nail ;-)