Vacuum bed

#1

Is anyone else thinking about a vacuum bed that might slide into the Forge to retain veneer items in place while cutting/engraving ?
I’m looking at the possibility of a slim bed, say 1/4" thick, with the perforated top made on the Forge (where else) about 12x15, with a plastic pipe connection that would come out of the pass through slot.
Not sure how this might impinge on the air assist or the fume extraction, but it would help in dealing with veneers that refused to stay flat, as I don’t want to fiddle about with double sided tape.
Any thoughts ?

John

Use crumb tray as vacuum table?
#2

I was planning on using magnets to keep lightweight objects in place. I don’t know if that will work 100% of the time, though.

#3

If you cover the whole bed, then maybe the vacuum won’t be to strong on the top side and pull down . I guess only pros could do this as you need a pump to constantly pull.

I’ve seen people use really big magnets. Maybe magnets and using mactact and kiss cutting an option? Veneers were one of the reasons I bought a laser.

#4

I need to pick up some “neodidlium” magnets…that one veneer sheet I got from Instructables is fairly warped.

(Or I’ll tape it down.)

#5

Magnets are the best way. If you are using a ‘full sheet’ you’ll be able to see the voids in the UI and strategically place them where they are needed most.

#6

Just as an aside if anyone wants to try it…I was also planning to experiment with using Krylon Easy Tack Repositionable Spray Adhesive #7020 on the back of the liner. That will likely hold even the pieces in place after they are cut. (It’s what we use to refresh the stickiness on the cutting mats in digital cutting…got a couple cans on hand.)

#7

Is that the ‘mesh’ that I see in the Forge pics ?

#8

No I meant the liner on the veneer. (The paper backing.)

#9

I wonder if misting it on the concave side would help, then compress?

#10

Ah, then slight complication for me.
I’m using two pieces of veneer laminated together for strength(slightly skewed grain direction) so I don’t use backed material.
But I’ll certainly consider spray adhesive on a cutting base as another method.
EDIT Now I think about it, having a paper on the front and back might have advantages.
I assume it peels of with no residue ?

#11

Well, it’s supposed to be flexible…so maybe it just comes that way. There’s a liner on the back of it, and adhesive. I’ll work something out. I’ve got a few tricks up my sleeve from working with paper, which is pure evil. :imp:

#12

Once you start cutting (assuming you cut all the way through) then the vacuum would be broken unless it is really strong. Given that the bed is ferrous, use of neodymium magnets is really the way (and you can get them in all sizes/shapes for super cheap on eBay…

Note: Given the rather impressive group of actively procreating 'forgers, please, please keep the magnets away from small children. Not pretty to have to resect the small bowel where the magnets strangulated 2 loops together after they eat them…

#13

Yes and no…if you apply it to something porous like paper, it’s pretty much a permanent feature. If you apply it to something like liner material, which is less porous (think waxed freezer paper) then it will hold anything TO the liner without coming off on the other material.

It’s going to require some testing. But that’s the fun part! :smiley:

Edit: you can buy the adhesive paper masking tape all ready to go, and it would be worth it from a convenience standpoint. Apply that, then spray the back of the paper tape with the Krylon. That should be sticky enough to stay stuck to that narrow grid. (So you would apply the paper tape to the back of the material.)

Edit #2: you spray 2 light coats of the Krylon, twenty minutes apart and let it dry completely. It stays tacky without coming off on anything, making the object repositionable.

#14

And sucking air out the pass-thru might severely mess with the GF cooling.

#15

another option is to use veneer softener and flatten the veneer.
http://www.veneersupplies.com/products/Super-Soft-2-Veneer-Softener-Conditioner.html

#16

And facing that ‘unknown’ at the moment, any adhesive method looks more desirable.

#17

My laser was used to cut a whole lot of paper-backed veneer (~500 1x2’ pieces). A big takeaway from that experience was that paper-backed veneer smells very, very bad when cut with a laser.

A vacuum bed would have been quite handy as the stuff apparently comes in rolls and it didn’t want to stay flat while being cut.

#18

Here’s the thing about vacuum ‘beds’ or vises. The ingest everything from the environment as they operate with a vacuum. So this means all the smoke and particles in the chamber are going to end up in the vise/pump. Or it may end up using the veneer as a ‘filter’ and suck everything into the surface. (non-backed variety)

On my smaller CNC I had to install a water separator on the return as it was pulling in some coolant. I guess you could add a filter- but that’s going to impact the suction performance.

The best thing to date what I have use on the unit we have was magnets. Attach to one end- Then smooth out then attach some on the other end. If you have high spots- just look in the preview and see if you can add some in those areas.

#19

So the top of my vac table for my cnc is just MDF, no perfferations. The vacuum pulls thru it. I think this would work good in the forge. And a shop vac should give more than enough hold down.

#20

So does the work piece need to be the full size of the MDF sheet or can you stick a small piece to it?

I ask because I have a vacuum table for my CNC mill but have never used it because I thought I would need to make a fixture for each job and mask off the bits I wasn’t using. Can I just put a big sheet of MDF on it and stick anything to it?