Use crumb tray as vacuum table?

I tried looking through past posts, but didn’t see if anyone had tried investigating the possibility of modifying the crumb tray to serve as a vacuum table. Per prior recommendations, I’ve been using a Seklema mat to cut intricate designs in card stock but i find that I have a few different problems with it:

  1. the cutout pieces of the paper get left behind when you remove the finished product, and they are a pain to get off of the Seklema mat. I am using a small metal putty knife, but there are lots of cut out parts in my design.
  2. when I go to scrape off the scrap bits, the Seklema mat (or the crumb tray) inevitably slides to one side or the other. This makes it difficult to line up the next job against my reference marks on the mat.

So I thought a vacuum table of some sort that you could switch on and off would be a good way to keep the small bits of paper from blowing around and not require scraping at the end. The best bet might be to use a small venturi vacuum pump inside the glowforge with a skinny compressed air tube going into the pass through slot. Maybe there is another way to do it?

I also see on sites like instructables the idea of making an MDF vacuum table with little laser cut holes in the top surface. That would essentially require replacing the crumb tray, but you might be able to fit in a vacuum apparatus that would do the trick? Maybe another approach would be to have an external vacuum pump but have the discharge line also be within the glowforge enclosure so you are not sucking out fumes through the pump into the room?

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This is a cool idea, one of your biggest challenges will be that you’ll have to modify your GF’s case, which will completely house your warranty. I think you’re right about needing to vent the vacuum line outside, smoke and fumes need to be filtered or vented.

In all I might think that a properly jigged setup where you set the mat against reference physical jigs might solve your alignment problem without resorting to a far more complicated vacuum setup, but that’s up to you to decide.

Here’s the type of 2-sided jig I might consider if I were you:

It’s been discussed a few times… :wink:

The grid on the tray is too open for a good vacuum table unless you can close off the entire stop surface while in use. All of the vacuum tables I have seen use small holes with a larger spacing so that you get higher hold-down while still maintaining a vacuum even if you aren’t using the whole table.

Yes, after I wrote the post, I also noticed that the entire front of the crumb tray is open. So a vacuum table will have to be a custom unit, replacing the crumb tray, and likely built from MDF.

I have a stack design in mind that I used in the past for my CNC router. I found a small vacuum pump that has 1/4" in and out tubing which I can hopefully squeeze through the pass through without having to modify the case or hide the pump inside the unit.

That was my thought - Pros have an exit/entry path for the required hose :slight_smile: You should wear your geek glasses when you run it but it wouldn’t void your warranty like drilling a hole in the case would (although that’s only a possibility - if the part that failed like the head or gantry wasn’t related to what you modified like a hole in the case, they’d have a hard time justifying a rejection of a warranty claim…but it’s just another headache to deal with and likely not worth doing until after the warranty expires). :slight_smile:

I was thinking of having the vacuum generator as part of the tray inside the machine, the fumes would therefore me vented inside the machine and handled by the normal fan, this would only require two electrical connections from the outside which can be run over the top of the door using wide and thin cables (e.g. flexible pcb). No modification to the device machine, no need to additional venting and there is plenty of space at the back of the tray for the pump. As for the grid I though of having some suction tubes (metal) placed inside selected grid spaces to be flush with the surface