My cheap, but "brilliant", venting solution

When I first got my glowforge, I cut some MDF with a hole in it to fit in my window to use as a vent. But I could not just place it in the window, because there is a lip all around the window. From the top, it kind of looks like this:

A rigid piece of wood could not be put in it. If I used wood that was thin enough to flex, it would not insulate much.

So I had to make it in multiple parts, and put each part in place, and screw them together in place.

So it looked like this:


It worked, but it was pretty “permanent”. To remove it I would have to remove the screws and it took more time than I wanted.

It was not a good solution.

I was playing with foam floor mats (making weapons for the kids), when a light bulb came on. Why not use these for the vent? You can find these mats at any hardware or walmart.


So I took one, cut it to size with an exacto knife, cut a hole in it for a vent fan with the exacto as well. I made 2 that were the same (so I could double up the layers). I made them fit snugly. It took me 10 minutes to make these, and they work like a charm!

They flex enough for me to put them in the window. They easily come out when I’m not using the GF. And they seem to be fairly well insulating, because I can’t feel a draft coming through the window at all. I think it was a “brilliant” use for this material!

Here’s what it looks like with the window closed:

I opened the window and took a top down picture.


It’s not see-through though. Anyone know where I can find see-through foam play mats?

I’m lucky that my window is not that big. Perhaps with a larger window, you could connect a few of these mats together, and cut those to size. If you use 2 layers, you could make sure the seams are at different places.

It works great for me. Your mileage may vary. :slight_smile:


Not getting into a chicken vs egg dilemma, but those mats are
usually made out of EVA foam and are (usually) laser-safe, so you could cut perfect, uniform circles with your :glowforge:.

YMMV. :innocent:


I thought of it. I even put one in the GF to test it. But it was too thick. I’ll have to take the bed out of the GF to get it to work. I did not have time to experiment with that yet.


No EVA foam you bought at a store is too thick to fit in the GF, certainly not the foam in the picture. GF has a height of 2 inches doesn’t it?
Might need to double check materials sheets. But it does say “tested for life in Canada”

It’s not too thick for GF, it’s too thick for GF with the tray in place. If I take the tray out, I can cut it, but I have not figured out the procedure to do this yet. I know there’s another thread that shows how to do it with Calipers, but I have not tried it yet.

Oh…the 2 inches isn’t with the crumb tray in place???

That sucks!

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Trying to think of why having to remove the crumb tray sucks? Takes 10 seconds.

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Because I thought the height of items you could put in the GF on the crumb tray was 2"?

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That’s 0.43 inches.


Ooof. So you can’t even fit 1/2" material under the laser?

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The head clears it, but the “cowcatcher” doesn’t. (Have no idea what the official name of that thing is.)

It’s possible to orient an object to miss that during the start of the routine, but it’s iffy. You don’t want to hit anything with it, it can knock the gantry off the tracks.

You can take the tray out though, and get thicker material in there.


My Glowforge is able to cut EVA floor mats. I was doing that last night. I cut it down to be as flat as possible, and run many light passes to get a fairly clean result.

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Really? I thought 0.433" was the current software limitation of focus, not the height of the air assist duct.


0.433" is a software limit. The air assist assembly (bottom edge) to the top of the bed is ‘roughly’ 0.602".


Whatever happened to the obstacle avoidance sensor? I have to constantly remind myself not to leave any coffee cups or saute pans inside the machine or risk one on’t gantry goin out askew on treadle.


Yeah. The piece of foam fit on the bed, and I was able to set the material thickness to 0.433" in the UI (even though it measured more like 0.47).

But every time it scanned my material, it would error out. I just figured the machine knows it’s thicker than what I specified because of the scan.


I’ve been meaning to test that one day … :thinking:but so far I’ve just drunk the coffee. :wink:


Who can argue with any idea that includes this statement? :smile:


It’s possible that the cowcatcher/air assist sits at a different height in the Production units. Mine bounced off of material that was IIRC 0.52 inches thick (Perfectly flat and taped down, not warped.)

(I believe this was before the 0.433" software limitation was included in the software.)

It makes sense that they’d set a slightly conservative value in the software to allow for warp, or variances in manufacturing.

Software limit or physical restriction, you probably don’t want the gantry jumping the tracks on you. Most folks should figure on a 0.43 inch height limitation on material put on the tray.

If you want to defeat the system, you can probably figure out a way to do it. But it’s a lot easier just to take the tray out. :smile: