Vacuum bed

It depends how much hold down you need. With milling if I’m really hogging material I will cover up the areas that are exposed. With laser I think it would be fine as there is no lateral force.

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I was thinking shop vac too, but I was also thinking about fast jobs, not ones taking multiple hours. The noise of a shop vac would be enough for me not to want to be around one, but I imagine their duty cycles aren’t suitable for jobs of that length either.

Yeah, if I use my Glowforge I think I’ll just stick with magnets.

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Depends on the shop vac. I’d suspect higher end RIGID brand/class shop vacs can handle the duty cycle (being left on for hours). However like some have said, not all projects will run that long. For those that are putting their GF in a “shop” setting, something to consider would be a Shop Vacuum setup, but not as in the portable type, but a plumbed system, where the vacuum would be in an enclosure. I’ve been in a few shops where even the air compressor (a very large two stage 15hp w/ a 100 gallon tank) was in it own soundproof closet with external ventilation to outside to vent heat and prevent overheating. It would run, but it was much more pleasant and not obnoxious at all. I think it was a few inches of styrofoam insulation on all walls and ceiling and the wavy egg-crate style foam on top of that.

I think the idea of a vacuum bed is great. I’m not personally concerned with duty cycles. Assuming the vacuum has sealed bearings, the only two things to worry over are ample cooling and brush wear. As it is I’d almost be tempted to get a big Harbor Freight Shop Vac and get the protection/warranty plan.

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There are also a number of liquid glues that are repositionable/temporary tack that might be worth looking into if you want something less messy than the krylon easy tack stuff (this may just be a me-problem, but spray adhesives and I are not the best of friends). For paper, I like a paper cement that is temporary tack unless you firmly burnish the pieces together, then it’s permanent. I think it’s called best test, I think. It doesn’t warp even really delicate paper, like tissue paper. It is a bit tricky to use in that once it’s dry, it won’t stick at all, and it dries fairly quickly. Plus side, it’s really easy to remove any residue that happens to be left behind.

I also like the tombow… Mono multi something something green bottle glue. If you stick something to it wet, it’s permanent, but if you let it dry completely it’s just temporary. This stuff is much stickier than the paper cement. So I would better trust it to hold heavier weight stuff. It won’t leave residue on the things you tack to it, but it’s never coming off the stuff you actually apply it too.

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Haven’t tried that Mono…might be worth picking up a bottle…it would be easier than the spray for sure. :smiley:

Whenever I use my shop vac, it seems I always get static shocks (am using grounded outlets). Could the GF be possible affected if that did build up? Personally I plan on using magnets, but just wondering.

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Surely any vacuum tray would vent fumes into your workshop?

I don’t see how a vacuum tray will work on a laser because being in close contact with the material means it will get hit by the focused beam and get hot. That is why honey combs and pin tables are used and you can’t draw a vacuum through those.

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The ‘tray’ is protected by the workpiece, and if one can ‘kiss’ cut through a sheet of labels, then I think it might be possibe to avoid the tray being cut. The surface layer of the tray might be a thin layer of drilled acrylic for example, cut on the Forge.

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I think you would certainly score the acrylic and each time you used it for the same job it would go a bit deeper.

I don’t think that would be a problem. The tray is inside the forge, and the only entry is via a small pipe.
Please bear in mind that the tray would be covered by the work piece plus any blanked off areas, so effectively only a small amount of air is being moved to make up for leakage through/round the workpiece.
As the laser does its cutting, the leakage will only increase by a factor of the kerf x length of the cut.
I have a shop vac in Corinth, so I’m familiar with its throughput, and that would be seriously OTT.
I have used vacuum hold downs on my cnc, and I know just how effective they are.
John

Then how does kiss cutting work ? Surely it depends on the focus of the beam ?

What is kiss cutting?

If you cut through something then the beam comes out the other side.

If you mean cut some labels but not the backing sheet then I have no idea because the difference in focus is negligible on a 2" focal length lens. The only way I could see that working is if the backing is much harder to cut material for the laser than the label, or much thicker than the label. Then again I have no experience with a laser cutter.

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There is a thread in Q&A on the topic.

It must just depend on how long the beam is there for and the power to cut to a certain depth because the change in focus through the thickness of a label is negligible.

If it doesn’t go through the backing, then yes a vacuum table made from acrylic would work and need very little vacuum. You would need a pro GF to get the pipes in though unless you want drill holes in the basic.

Yes, I’m going with the Pro.

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A reversible aquarium air pump would be enough to hold down labels and the pipe would fit through the pro slot. I used one to pick up CDs in a jukebox I made many moons ago: http://hydraraptor.blogspot.com.es/2007/06/day-music-died.html

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We vacuum a lot of plastic chips and that makes enough static that you can’t even hold onto the thing. So what we do is run a bare copper wire down the outside of the hose and to the ground on the outlet. Before we did this it did it did zap my CNC and cause propblems.

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To pass CE certification the GF will need to pass a static discharge test.

Now that’s my kind of idea :slight_smile:
Awesome jukebox.

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