2 inch high item - help with the math!

Hi Makers,

So I need a little help with my math… I have a 2-inch high board that I am printing on. I took out the crumb tray (obvi!) but I want to make sure I am doing my math right before I push that lovely flashing button.

Item height (2-inches) - crumb tray height (1.375 inches) = 0.625
This is the number that I should be entering into the material thickness, correct?
Yet, I can’t, because the highest I can go is .50. What am I doing wrong in my calculations?

Thank you all for your help!



I use this, and then I use set focus.

Wait, is your crumb tray in? Sorry, I guess I’m not following. I usually use that ruler to make sure my material is in the right position to use set fous. If you use set focus, you don’t need to enter the material thickness…unless set focus can’t figure it out.


Your math is fine, but your board might be too tall.

Place the board in the machine and with it turned off, move the head by hand slowly out over the board to see if the air assist diverter hits it. (Do that before moving the head back to the home position and turning the machine on.)

Don’t try to do it using math, that tenth of a inch might not be there, and if it’s going to work, the auto-focus will do the calculation. (If it doesn’t clear, take that board out and try a thinner board, before turning it on. Don’t let the head hit anything, it can jump the gantry off the tracks.)


I allways have to brainstorm myself each time I have to cut without crumtray.

So I have made a excel calculation tool. It is in mm but some correction on formulas would transform it in inch. Since now I have found it useful.

Let me know if I do the right math. Glowforge - cutting without crumbtray - calculation.xlsx (10.6 KB)


Just use this:

If it fits, it prints.


I used to use calipers, make sure everything was measured correctly, etc. With the addition of set focus, I rarely do that anymore as it is spot on and makes it so much easier!


Since they came out with set focus you never have to measure or enter thickness manually ever again. Just use the No-Math Focus Ruler posted above to make sure your material is within the height that the GF can process and use set focus.


I was looking at this too, but since I’ve never used it, only the other one, I wasn’t quite sure if I understood the situation enough to suggest it.


HI Jules,

Checking the height and making sure everything clears (with the crumb tray removed) is the first thing I did (I forgot to mention that).

Since it does clear, do I just enter in .50 (the max height the GF will accept) and then let the senor do its thing?

Thank you very much for your help! Much appreciated!



Hmmmm, (thinking) :thinking:

Put the board in, turn on the machine and let it do the startup calibrations, then click on the board with the Set Focus tool and it should go all automatic from that point on. (In other words, you shouldn’t need to set the focus height, although you will need to specify the Engrave settings in Manual. Just the speed and power.)

It might still throw an error, but it might let it process. That height is pushing it. (I get uncomfortable with anything over an inch and three quarters, because I like to have a little leeway so the lens doesn’t get cruddy. Just keep an eye on it for a bit to make sure it’s all still blowing forward.) :slightly_smiling_face:


Crumb tray is out.

Forgive my ignorance…what does UI stand for (I’m a mega newbie, lol)

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User Interface