# Cutting Without the Crumb Tray - The NO MATH Edition

#41

It can be hard to wrap your head around. This visual really helped me “get” it:

#42

Think of it this way: The laser only “sees” a half-inch slice of space – located from the surface of the crumb tray to 1/2" above it. Anything sticking up higher than that will be run into by the air assist, and anything below that is too low for the laser to reach.

So if you want to put something thicker than 1/2" in there to laser on, you have to take out the tray, but make sure the part to be lasered is sticking into that 1/2" space. That means that 1) you have to figure out how much stuff you need to stick under it to get it up high enough, and 2) you have to figure out how far into the 1/2" space it extends, so you can “lie” to the glowforge about how thick it is, by telling it just the amount of the item that exists within that space.

Hopefully with that explanation, and the picture, you can go back to the instructions @Jules wrote and they’ll make more sense.

#43

This! This makes crystal clear sense to me. Thank you so much. I could instantly visualize what I need to do to make it work out. Seriously, you are a true gem of a human.

#44

Nah, I’m just more of a kinesthetic learner, and you probably are too, so we share the same “explaining” language. I had to go through @Jules’ steps a bunch of times before I finally realized what was going on, and then it just clicked.

#45

You have said a mouth full right there! This does not happen to me often but when it does I wonder out loud if I’ve just had a stroke!

#46

Quick set up jig.

#47

I like that gauge a lot. I wonder if rule marks between the min and max would be accurate enough to measure directly off the gauge.

#48

I know this post is a year old - but just in case you never found it again: Tray Removed - Calculator - Updated

I just hit this thread today - I haven’t done anything without the tray yet, but it’s coming soon

#49

That is a great idea!

#50

I take a different approach.

Place your calipers against the side of your cutting head, depth gauge pointing down, starting flush with the bottom edge of the black plastic (nearest to crumb tray).

Now, extend the depth gauge until it touches the crumb tray (you may need to move the head or calipers slightly to get the two small metal bits aligned to make contact). At this point, zero out your calipers.

Now, to measure the height of any object, you just put the digital calipers back up against the print head and extend the depth gauge once again. As long as your reading is negative, you just enter that (as a positive value) exact measurement as your material height. If you do get a positive value, then you need to add some material underneath whatever you are working on, and what you add should be at least as thick as the positive value showing on the calipers.

This works for even finding the material height of things when you ARE using the crumb tray, but forgot to measure in advance of putting it in the machine (I am frequently guilty of this one).

Of course you could do this with the calipers pointing the other direction, extending the head instead of the depth gauge. That would make it easier to hit the crumb tray regardless of positioning. Not sure why I do it upside down…