Hold-down clamp mounted on T-track cam lever

[fschock]

After reading David Buchsbaum's Shopbot Web Column, "Meet My New Friend, CAM", I decided to make a set of four with an added-on, hold-down, clamp. To the left of the pic is the assembled cam/clamp with views of the components to the right.

[gc3]

Nicely done!

[beacon14]

Very neat, Fred. It looks like you reversed the cam action so the fit is tighter with the handle aligned with the edge of the workpiece instead of at 90 degrees like mine?

Just watch out for those clamps! That looks like a big target to me.

[laconcepts]

David. See another, ever growing version of your clamps inspired me to show you my allaluminum version. They work great. We are planning a PVC vacuum table (we bought 1" PVC) and will be installing T-track. I expect the clsmps to hold even tighter then.

Thank you for the idea and diamensions.
Kelly Watkins (Mr)

[laconcepts]

Please forgive the typos. i should have reviewed. Getting use to this digital/virtual/touch screen keyboard on my HP Slate. hehe
Kelly

[bleeth]

Kelly:

I first used 1" PVC for my table and when I changed it to 2" the improvement was dramatic with the same vacuum.

[Acmeaviator]

Rockler sells a track and clamp kit that I have been thinking of adding to my bot. So far I've just been screwing work into a sacrificial MDF layer over my table - which at least has the advantage of giving a newbie like me smaller pieces of metal to avoid Now that I'm feeling more confident in moving the bot exactly where I want it I'd like the ease use that clamps would provide. As has been said many times by us Buddy owners - love the flexibility and small footprint but hold-down can be a pain.

[laconcepts]

Dave,

What kind of problems did you encounter with the 1"?

We recently bought the 1" at for our shopbot at barksdale AFB
so i doubt They will be buying me more for a while,..hehe
Since we will be cutting T track unto it as well as the vacuum grid,
I considering used asheet of plywood or something else under it to give the pvc additional support.

Kelly

[bleeth]

Kelly: I was referring to the diameter of the vacuum pipe. I first used 1 (or maybe 1 1/2") but went to 2" when I was making some other changes to my table and the increase in holding force was dramatic. My table base is a couple layers of 3/4 ply with one side laminated with HPL and edges sealed.
Then the vac plenum out of 3/4" MDF (8 2x2 zones) followed by the spoilboard. If I'm carving a small piece often I will cut a mask out of some scrap and hold down with vacuum or clamps on the mask but most of our work is panel processing so T-tracks would be wasted.

[backyard_cnc]

Dave,

I wonder how deep you routed each of the zones for the vac table? What sort of pattern did you use? What is your Vac source?

Appreciate your comments. I am new to SHOPBOT having recently purchased a 2004 vintage PRT96. A vac table is on my list of "Really like to have's!"

Cheers

Gerald