Clamping

[TReischl]

Finally got fed up with my crummy collection of wood blocks, etc and got busy.

I use aluminum clamp bars, but all the rest of the stuff was pretty pathetic so I put the 3D printer to work.

The knobs have a hex nut inserted. Each one costs about 16 cents to make.

The most interesting part is the blocks. Each block has five different heights so I do not a pile of blocks anymore.

Also made up a set of stops or locator pads. I might make a few more of them a bit longer.

A 3D printer is a really handy tool for the shop.

[Adrian]

Definitely. The things I've made most with my 3D printer (next to bits for the race car which is why I bought it) are various clamps, knobs and general fixtures for the CNC.

[4DThinker]

I also have 3D printers (2 at the moment) and use them for similar parts.

About aluminum clamps just be wary of your tool paths and where the clamps are. Not that a router bit can't plow right through them, but for the chance cutting one may loosen the work being cut. I know from experience. Of course the same is true for wood clamps.

4D

[TReischl]

I also have 3D printers (2 at the moment) and use them for similar parts.
About aluminum clamps just be wary of your tool paths and where the clamps are. Not that a router bit can't plow right through them, but for the chance cutting one may loosen the work being cut. I know from experience. Of course the same is true for wood clamps.
4D

There is a reason I use aluminum clamps. If you look closely in that picture you will see that each clamp has a small notch cut in the end of it creating a step. That step is 1/8 by half the thickness of the clamp, 3/16. That does some things that are very useful, like let me know where the edge of the clamp is on the board. I tried that with wooden clamps, it does not work because the wood will split when force is applied.

Also notice that I use 4 clamps. I always use at least 4 clamps. If only two clamps are used exactly what you describe can happen, the work piece can get loose if one of the clamps is struck.

One thing that makes me cringe is when I see a piece clamped and the bolt is closer to the end farthest from the work. It is a physics thing, the block has more force applied to it than the workpiece. That is one of the reasons I do not like or use the "t nut" grid method of clamping. Using that method quite often causes the bolt to be in the wrong place unless the t nuts are spaced really close together.

BTW, for a lot of the work I do, I do not clamp the work on the top surface to begin with. Most of the time I will cut two grooves on the edge of the workpiece on the table saw and put the clamps in those grooves. I especially do that on thick work pieces. But, what I do most is a use a pair of vises, so no "clamps" at all. I do very little sheet work at all. Just not my thing.

[Tailmaker]

I use 80% of the time a custom vac pod (a.k.a. some weather strip on a disposable piece of plywood). But when the parts are too small to develop meaningful hold-down or when they have holes or small strips, I sometimes do use aluminum clamps.

While my clamps have a bunch of battle scars from collisions with the bit, these are mostly from years ago when I was too stingy to make my blanks large enough to be clamped safely. Nowadays I give the clamps sufficient margin to not get mangled and have not had much trouble.

If the blank is rigid and of moderate size I normally clamp the blank onto 4 small plywood blocks under the four clamped corners so that it is free hanging and no spoilboard is needed (works only with tabs). The blocks have on both sides a liner of anti-slip material to avoid moving on my slick t-slot extrusion table.

If the parts to be cut have anyway holes for dowels or screws I cut/drill the holes first and then screw the whole thing down on a disposable spoilboard before doing final cutout and save the tabs. This spoilbord may be clamped or vacuumed to my extrusion table. depending on size. For that matter, several of the 80/20 profile t-slots are covered with aluminum flashing and dedicated as vacuum conduits that can be tapped anywhere along the length.

[TReischl]

Tail, that is an interesting set up you have there.