Suggestions on trimming 1/8" off the edge of an acrylic sheet

Hey all! Apologies in advance for the noob question . . .

Tomorrow I’ll get the Glowforge turned on and set up and can start using it but haven’t yet. I have to trim down a bunch of 1/8" thick acrylic sheets that are 1/8" longer and wider than they need to be.

I want the Glowforge to trim exactly 1/8" off the long and the short edge of one side of the acrylic but I am concerned that there isn’t a way to line up the material to do this cut the way I’d approach if it I were doing it on a table saw for example with a fence.

What is the best way to perform this cut with the Glowforge? Will the software show me the current angle of the material (since I assume absolute parallel with the machine is impossible without a fence) and give me some way to draw a line and cut?

I know its a silly question but I haven’t ever had to think about how the Glowforge would align and cut from the edge of a sheet of material and hold that same angle to cut away the thickness uniformly knowing it could be at any angle on the crumb tray.

Thank you in advance for your help all!

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How big are the pieces?

If they fit in the bed, no passthrough needed, etc. I would set up an Illustrator file with a stroked rectangle to the appropriate dimensions. Then, a copy with a different stroke color, and resize it appropriately (-.250” to overall L and H). Align that to horizontal and vertical center.

Upload the file. Put a piece of waste material to use as a jig in the GF. I cut 12x20 chipboard pieces and align the corner to a piece of tape on the crumbtray rail. Run your outer cut. Remove that cut. Place your acrylic. Run your inner cut.


11" x 14.625"

Sorry - I edited my initial post but it probably won’t notify you of that. :slight_smile:

Thanks for the help! I have a quick follow-up . . .

How or where do I tape the chipboard to keep it from moving around as I swap out sheets of acrylic?

Also, thinking I could use some other spare acrylic sheets I have to make the jig and align it to the back of the crumb tray so I could just slide in each sheet as needed, yes?

Also, do I need to then repeat this for each side I want to trim? So for instance trim all the sheets horizontally (on the long side) then create a new jig and them trim all the sheets vertically (on the short side)?

Wasn’t sure if it was possible to do this with a single cut that turns a corner or if I needed to set it up with multiple set-ups of two straight cuts.

Thanks again for your suggestion!

Given the size of the piece you are cutting, you could just use a spacer bar or two. You can place anything that is perfectly straight (a plastic ruler for instance, or a piece of wood cut perfectly square, flush against the front door of the machine and then line up the acrylic against it. (Basically make your own fence.)

Then you just need to draw a horizontal line, save it as an SVG and use it on the acrylic. Since the line is horizontal and the material is squared up against the front, you should be able to place the line and trim it with good accuracy.

You can also place a spacer bar against the side edge of the tray for vertical lines.
(I use a lot of spacer bars…they make easy jigs for horizontal and vertical cuts.) :slightly_smiling_face:

Spacer bars would work for sure.

On the chipboard, I don’t tape it down. I just have a piece of electrical tape down on the lower left rail of the crumbtray and align a corner of my board to that. I can take it out, place it back in, and as long as I align to that piece of tape, I’m fine.

As far as your cuts - you could do just straight cuts all the way across to trim it proper, or you could just inset a rectangle 1/8” and cut a rectangle. You just want 1/8” off all the way around? Or on a certain edge?

Either way - the trimming is the easier part. The placement takes a hair more work (but not bad at all after the first time).

I align and cut stuff all day long usually, so that’s how well the process works. I don’t have to move anything at all in the interface. I just set power and speed, and push the glowing button.

Thanks Jules! Since I have the Pro model and don’t yet have the metal bars to close the slots, the material can pass through the front or the back pretty easily.

The good news is, after some looking the crumb tray does have a nice edge I can use as a fence. The question is, how does the machine’s cutter measure from that edge? I assume I’ll have to create a spacer bar that creates my zero point for the sheets so I can find that 1/8" easily on the far side of the sheet and trim it.

Any suggestions on the power and speed I’d want to use for this? Will it recommend?

Extreme accuracy becomes a little more problematic due to the current limitations with visual placement.

Here’s an idea - the problem will be cutting the 1/8" off of the 11 inch side, since the current cutting area is only 11" deep. But you can anchor the material itself against the front of the machine, and the back will then fall into cutting range. Do some testing with cardboard that is exactly as wide as the material you need to cut down, and adjust the placement of the horizontal line until it cuts exactly 1/8" off of the cardboard - then DO NOT MOVE THE LINE. You can insert the acrylic sheet - cut the 1/8" off, insert the next one, cut 1/8" off, cut the next one…etc. Basically just use the machine itself as a fence or jig.

Then do the same thing with the side - anchor on one side of the tray, (there’s a little lip), test it on the cardboard and again, do not shift the vertical line once you have it set up correctly.

Don’t use the passthrough - you need to be able to anchor against something horizontal like the front of the machine. And you can use the Medium Proofgrade Acrylic for a starter setting.

One heads up…this presumes that the material you are putting into the machine is cut square - if it’s not, and it might not be, it ain’t gonna work.

Good luck! :grinning:


Thank you Jules and JB for all your help! I’ll let you know how the first attempt later today goes!