Material Height/Focus height stuck?

[mike20]

Two Questions similar topic. I use a lot of my own material which varies from .25" to 1 inches. I discovered that anything below .5 inches I can leave the bed in and when using over .5 inches I must remove the bed. However according to the laser warnings the material must be positioned I so as the top of the material falls in between the magic .5 and under or 1.5 to 2? what about material that falls in between these. Not only do I get the above warning but I discovered if the materiel is to tall it will hit the guard under and to the back of the laser head. So what I have be doing is anything under .5 business as usual. But my material over .5 such as a oak board .85 inches thick I have to remove the crumb tray place something underneath it to raise it over .5, measure with calipers and enter that number into the material thickness…Am I blatenly missing something here or is the only way to engrave items thicker than .5 is to get its overall height when sitting in the machine with no bed to over .5. That means I will constantly have to have multiple riser board with various thickness’s on hand to get my varying material to sit above 1.5 inches?

Second the quality and alignment seems great on my own material, but when I enter the material and focus height say for example 1.62" and hit apply it always changes it back to .5 in the box. It will never keep what I put in. Again probably something very simple but what and I missing here?

MW

[Jules]

You’re on the right track. One thing you might be missing is that the value entered into the Materials Height slot is the difference between the top of the object to the top of where the tray would normally be. (So it has a maximum value of 0.5 ")

For your example, it would be 1.62" - 1.38" (top of the tray)=0.24"

You seem to have discovered most of these things for yourself, but there are several discussions, and quite a few methods for propping up materials to be engraved in the Free Files section. Folks have gotten very creative with everything to 3D printed and wooden props to bars that span the bed and 3/2/1 blocks.

I’ll link the calculator and a writeup or two with diagrams below so you can verify what you’re doing.

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…

Tray Removed - Calculator - Updated

After seeing a couple of people talking about the correct way to do this I made a calculator to simplify the process and hopefully demonstrate the goal. All you need to do is add the height of your object and the base you want to use and it will tell you if it will work or not and the setting to use in the GF, if it won’t work it will tell you why. If you don’t have a base in mind just put 0 and it will give you the minimum needed. [image] Zip file TrayCalculator3.xlsx (33.8 KB) Dropbox in …

Be sure to check out the shared files in the Free Laser Designs section for the props.

[mike20]

Top of the bed huh. Makes sense I will try that…whatever I was doing seemed to work but the long way around. Thanks for the info…the without tray info is going to be great. Thank you!

[dannyc]

Thanks for the answer @jules, that is a great link as well! I’m going to close this thread - if the problem reoccurs, go ahead and post a new topic. Thanks for letting us know about this.