Nice design. Will be following this thread to see how it performs. Please keep us updated.

 

Great Idea!
Thanks for sharing.

 

Great for working with engraving and cutouts, making sure the work piece is flat against table.

How is it working out with, say detail engraving where the work turns the surface into rough terrain for the 'sled' ? Didn't look to see if the edges are rounded to slide up/down ... maybe use HDPE as it tends to be slippery ?

 

Indeed those thinner material are always far from perfectly flat. Even 1/2" ply tends to "curl" ...

I just cut a Croquignole game out of a 32"x48" piece of "good" grade 1/2" ply with myOX I wished I had a vacuum table ... or something. Your concept would of been perfect, especially as the cutout is being done ... the plywood "sprung" up since I had not allowed for tabs ... got lots of HDPE bottle caps and such ready to melt and shape. So I'll take a closer look at your prototype and see if I take the plunge.

Thank you for a great contribution. You should probably make it a "Resource" so it doesn't get buried in a discussion.

 

Any updates on this?

 

I have been playing around with a similar setup to this to cut 3.175 mm thick material. My build is a bit different, but the same basic idea and so I think the same principles apply. Here are some usage notes so far:

(1) Weak springs will not hold parts in place perfectly. With weaker springs, I would still notice some edges of the part where the part had shifted and so the spindle had cut some out.
(2) Strong springs work much better at clamping. But strong springs provide a lot of pushback like you are plunging into a hard material even when you are cutting into a soft one.
(3) If there is flex in your x-axis, the strong springs will exercise it. And you can easily get into situations where it is hard to precisely set z-axis settings because when the z-axis screw turns the system flexes instead of plunging.
(4) So be ready to have your spoilboard really act as a spoilboard. Because you will be unlikely to get a perfect z-axis cut even with a touch plate and a lot of futzing.
(5) It works best if you cut down to an onion skin and then cut the last layer away afterwards.
(6) My vacuum doesn't suck up all of the swarf material. But the OP looks like they have a more airtight system so it may work better. The vacuum at least keeps it all contained for later cleanup with a secondary vacuum.
(7) The lower ring has to be absolutely flat on the table. Otherwise the linear guides can bind and that can be very bad. I found that the best way to do this was to loosen the assembly, lower the z-axis so that the ring was just touching the table, then hold the ring flat as you tighten things up again.
(8) The lower ring takes up a fair amount of space and it can never touch anything taller than the workpiece. No clamps can be within 40 mm or so of it (depending on how big the ring is). Even screwheads that sit above the plane of the workpiece can cause troubles.
(9) This setup works best when you have large workpieces that you clamp at the corners or which overhang the table and are clamped well outside of the work area. A 6" x 6" piece clamped on the edges gives you maybe a 2"x2" safe working area. A 24"x24" piece clamped at the corners gives you a working area consisting of the whole workpiece except for a couple of inches from each corner.

This is an essential upgrade if you want to cut a lot of small pieces and have a machine that can handle the extra stresses while being large enough to get a usable workspace. I really hope to see more of the OP's build progress because this is such a useful upgrade.

-D