Trouble with alignment

[Jules]

@manderson24306

The discs we engrave on are too thick to use the crumb tray, but they sit 1.5 in below the camera so there is enough room. The PROBLEM is when it is aligned on my computer screen (with a jig and without) and I hit print, it comes out misaligned on my piece of wood.

If the top of the disks is sitting 1.5" below the camera, there is no way on earth that the beam is going to be able to focus on it. So i’m not surprised that you are having alignment issues with those.

If you are cutting without the crumb tray, you have to prop the material up so that it falls into the correct engraving zone. The engraving zone is about half an inch from the top of the crumb tray down to where the surface of the crumb tray would be if it were in there.

Trying to engrave on an unsupported item is probably why the alignment is so far off on your lids.

The other thing that you have to do every time you try to engrave without the crumb tray is correctly calculate the “Thickness” of the material and enter it into the Unknown Materials slot. I have that highlighted because it’s not the actual thickness of the material that you will enter in this case, it is the thickness of the material that extends above approximately 1.4" as measured from the metal plate on the bottom of the machine.

The honeycomb surface of the tray is considered the zero point for focusing calculations. The laser can only focus correctly in the half inch range that runs from the top of the honeycomb and half an inch higher than that. So you prop the material up so that the top surface falls into that range, then subtract out 1.4" to get the correct thickness value for the Unknown Materials slot in the Thumbnail column.

There are a couple of very good tutorials here that explain what you have to do:

Tutorial: How to cut without the Crumb Tray (Honeycomb)

Tutorial: How to cut objects too thick to have the honeycomb in place The GlowForge has a maximum material thickness it can cut through, but there is a maximum thickness you can even put on the honeycomb (crumb tray) even if you are surface engraving as the laser has a limited focus range of 0.01" - 0.4" *** above the surface of the honeycomb at the time of this tutorial. But let’s say you wanted to engrave something thicker that fits quite nicely inside the GlowForge but not with the crumb tray…

Cutting Without the Crumb Tray - The NO MATH Edition

There’s a great tutorial here on cutting without the crumb tray when you want to work with thicker material. If you want to know the numbers and theory behind it, go read that first, and then come back. Thank you, @henryhbk! This method uses the digital calipers you should already have, and the not-used-often-enough ZERO button. We’re going to go through the steps from the tutorial above, but without any math or writing down numbers. The first step is to find the height of your crumb tray’s su…

That’s part one.

The second issue that folks are trying to help you with has to do with achieving perfect alignment through use of a jig, instead of just trying to eyeball it. It is more accurate (100%) and taking the time to do it is going to be a real time saver for you if you have a lot of the same shape to engrave on…you just cut one jig hole, drop each lid into it, and engrave it perfectly. But it’s harder to do without the tray in place, you would need to prop the jig up as well. Maybe a small sheet of plywood propped up on scrap wood. As long as you do not move the jig or any of the images on the screen, it will engrave in the correct place.

But look at the tutorials for cutting without the crumb tray first…I think that might be the main problem here. You might get good enough results once you get the material into the correct range with the correct thickness listed to not have to mess with a jig.