How do those clamp holes work?

I see a lot of finished machines that seem to have a uniform grid of holes into which hockey-stick-looking clamps are screwed down with machine screws (see attached for example). It seems to be a standard way of doing hold-down clamps, but I can’t find anyone describing the exact construction.

Here’s my supposition based on the picture – is this the right way?

  • To make the holes, I see no reason why the machine can’t do that to itself, right?

  • Next, people seem to be using machine screws, so are they adding tee nuts on the back of every hole to provide machine screw threads?

I know this may be remedial, I’m just surprised I couldn’t find anyone actually talking about this step…maybe I’m just googling the wrong thing?

It´s a wasteboard, you need to buy some threaded inserts like this drill a hole and screw it, you can drill the holes with your cnc

I either just clamp on the outside, screw it into the waste board, or I have some holes drilled and I can clamp through that. Screwing into the waste board is pretty easy. I use that the most if it isn’t big enough to just clamp on the outside. All depends on the kind of work you will be doing. I would only use those if you are using small stock all the time. Most things I cut hang out of the machine and are easier to just clamp, and the rare occasion I am using something small I just double sided tape it down or screw the edges like tiny clamps.

Thanks - just bought those inserts. Should be easier than tee nuts.

I plan to use it for all kinds and sizes of stock, so I may as well build a nice mounting board to make it easier.

I just use a washer and a sheetrock screw and screw it into the waste board.

If you go to all the trouble with the inserts aren’t you going to be doing it over and over again when you need to replace the waste board? If you do it with the inserts are you just putting them around the outside or the cutable area or something? If you have them through out the field won’t you hit one with the tool?

I am thinking about when you are cutting out things so you cut all the way through the piece aren’t you cutting into the waste board a little too? I am a total novice so I could be doing this wrong.

Generally the inserts come in from the bottom and don’t go in to the spoil board very far. So you shouldn’t hit them With normal through all cuts, but yes you need to take them out and do it again when you replace it. Depends on what you are cutting, they can be a real time saver for some.

That makes more sense then. I was thinking they would go in from the top.

I’m planning to use a separate spoil board on top of the base every time, and the clamps grab from the outside, so ideally I’d never cut into the actual base board of the machine, assuming I don’t screw up.

But I’ve never done this before either, so who knows?

I have drilled and tapped the holes in MDF or plywood.
If you strip out an occassional hole, use another hole.