Small Vacuum hold down

Had my X-Carve for a few weeks, enjoying it a lot, but finding that I don’t like using tabs or double sided tape for small pieces. Here’s what I’ve had happen:

  1. If I have a small piece that is thin, it’s really hard to get up from double sided tape without damaging it

  2. If I use tabs and clamps, then by the time I sand the tabs even usually I’ve screwed up my part. Not saying this is an X-Carve problem, more mine. plus some really thin parts, the tabs are as thick as what I’m carving!

So, I figured I’d build a small Vacuum clamp. Here’s a few things I learned that might help you if you decide to go this route.

First off, try to keep it small. Mine is 5" x 14", which is the same size as the stock I’m carving. I bet you could probably double that and still keep good suction, but not sure beyond that. This works well.

I went ahead and had 1/8" holes so I could use the same bit to cut the pieces out and drill the vacuum holes. Built it with MDF, which yes, is NOT airtight, but I used a liberal amount of tite-bond II and also taped the outside with blue painter’s tape. It’s ugly but functional. Inside I also took the tite-bond II and used a squeegee to put a thin film into the MDF, in an attempt to seal it a little better.

Two pieces of 1/4" MDF were the top and bottom, top had 1/8" holes drilled every 1/2", staggered so it wasn’t a square grid, more like a chinese checker pattern. Center piece was 1/2", and had a gap in it for a vacuum attachment - the narrow flatish one that you use for getting into corners and such. Seemed easier than making a ring sized for the vacuum hose and trying to adapt that.

So basically I just clamp my 1" thick vacuum ‘box’ that measures 6" x 16" to the board, place my piece I’m carving on it, make really sure it’s how I want it, then I turn on the vacuum. It sucks it down hard enough that I cannot move it while the vacuum is on. Then it’s Carving Time.

I’ll probably make a nicer one later, this was more of a proof of concept thing and I didn’t really want to spend a lot of time making something nice and then having it not work. This is ugly but functional. By the time I’ve used this several times I’ll have come up with ways I would done things differently, I’ll make that part of vacuum table 2.0 :slight_smile:

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Pete,
I’d love to see photos of your clamp. I’ve really been thinking of making one myself.
Specifically, how are you directing the vacuum within the middle piece? Is it as simple as having a hole drilled into the “end” of the board so the vacuum attachment sticks into it and it somehow flows through the entire piece?

Thanks!
Rick

It’s ugly. really simple to make though - top has the holes, bottom is same size as top without holes, middle piece is basically just a horseshoe shape with the bottom closer together for putting the hose attachment in. My sides were about 1/2" thick on the sides, all of the inside is hollow and works fine. If you made a bigger vacuum table you might need to get more clever with internal porting and such but basically it’s a hollow box with holes on the top.

One thing I did neglect to mention is that if you are carving a piece that is much smaller than the top (meaning you have vacuum holes open/not covered up) it will severely affect how much suction you generate. I was kinda hoping to leave some open so I could maybe pull some sawdust out of the air / mitigate the mess a little but more than a few open holes and you just don’t have as much gripping power.

Your vacuum box is small, but keep an eye out for deflection in the 1/4 top board. I probably would have put some MDF strips glued inside, not the full width, and staggered, to allow air to ‘zig zag’ around them. I’ve also seen the outside sealed with several coats of wood glue and water mixed. I haven made on myself yet, though, so I can’t speak from experience.

Great idea on the MDF strips inside. Not so much for airflow but of a way to keep the top level. However, I haven’t had any problems with it yet. Certainly something to do on my next version!