Shop made workholding clamps - Assembly question

[Analias]

I'm putting together some workholding clamps that I want to use on my CNC mill and CNC router. I'm modeling them after Bob Adams' clamps [1] . Instead of aluminum, I'm cutting them out of 1018 cold roll bar stock for the sides and 12L14 round for spacers and pivot. Bob's design used 8-32 bolts/nuts to hold the clamp together. I can do the same, and even bought additional 1/2 12L14 round to cut them out of. I'm considering alternative approach of simply using a 1/2" spacer drilled for 1/4" and either swaging a brass tube or using a brass pin as a rivet. I was curious if anyone had any alternative ideas?

If your curious how these clamps could be used on my CNC mill and CNC router, I was planning on making two sets of pivots. One drilled for clearance for 1/4-20 bolts for the router CNC router and the other for 3/8-16 bolts for the CNC mill.

-Freeman







[1] http://www.cad2gcode.com/cncprojects/id14.html

 

[TomS]

Why not make the rollers out of 1018 CRS, turn each end .250 diameter (to fit the side plates) about 3/16 long and plug weld them in place. Sand the sides smooth on a belt sander, or file them. Your clamps will have a clean appearance with no hardware to gather chips. I'm assuming the rollers don't need to turn. If that's the case them trash my idea.

Tom S.

 

[DaveSohlstrom]

Freeman

One thought. change out the socket head cap screw for counter sunk cap screws and tape one side plate 1/4-20 then you can get right up against a part or slide by the clamp with your milling cutter.

Dave

 

[DMS]

Here is my take on those clamps

[thread]6647[/thread]

Bodies are aluminum, and the pivots are drill rod. I have grown to love aluminum for clamps because it's soft, and grabs hold pretty good. I think what you have will be fine. As far as attachment, the only issue I can see is the SHCS sticking out the side, they may get in the way sometimes. If you switch to a threaded spacer, and drove flat head machine screws in from either side, you could have a clamp with no protrusions. I would also recommend some loctite; you don't want them rattling apart on you.

You could also get the same effect by swaging or riveting. All depends on where you want to spend your time.