Figuring out settings for nonproofgrade materials

settings

#1

I’m trying to run tests to figure out settings for all the materials I have. Seems like it should be really obvious, but I’m sure exactly if I’m doing it right.

For example, I have some super thin wood. I randomly started at 300 zooms… because it was the middle. Then, I did 10 to 100 pews, in increments of 10, cutting little squares. 60 didn’t cut all the way through, 70 did, so I tried 65 and it worked.

So, am I done? I assume I could also cut through going faster with less power or slower with more power. I expect I could find at least a handful of combinations that work. Is there a benefit to going slower or cutting with more power? Like, do higher power cuts use up the tube-y magic faster, so I should be trying to find the lowest power cut possible? Or do slower cuts just take longer, and I should be look for the fastest setting that works?

How do other people zero in on their settings when they don’t have a starting point? I feel like I’m missing something.


#2

Rule of thumb that clearly doesn’t always hold is that you want to do cuts a full power and dial down the speed until it cuts. And engraves you want full speed and dial up the power until you get the result you’re after.

The idea with that is that you just get your result faster, but also less time in one spot is usually better for the laser side effects.

There are obvious exceptions to this. One is that the Glowforge doesn’t do fast corners very well (over burn) so slower lower power mitigates that. Another is that some material apparently behaves better with lower power and slower movement.


#3

Oh! Thank you for mentioning this – I did little squares and noticed that the corners were a little too burny. I didn’t realize there was a way to fix that. More work to do :slight_smile:


#4

The Glowforge can’t instantly change speeds, so it has to slowdown into the corner and speed up coming out of it. In a perfect world it would adjust the laser power accordingly (3D printers adjust the flow rate, for example), but either they haven’t got around to that or they’re hitting a limit on how finely they can adjust power and get a consistent result (some evidence on the dithering indicates it may be the latter).

Another consequence of this is that experiments on small squares may not hold for long straight cuts. At faster speeds, the long straight-away may get a lower power density than near the corners and not cut all the way through. This more likely to be a problem for materials that can be cut quickly.


#5

I would love to see my glowforge stop burning my corners because of deceleration/acceleration. The uneven application of laser power at different parts of my designs is making things difficult when trying out new materials and trying to get the settings dialed in.

@dan - can we add this to the hopper, please?


#6

Already in the hopper.

If you use settings similar to the HQ score, you can usually mostly eliminate any over burning in sharp direction changes.


#7

Great, glad to hear it!

…with a new material I have no HQ score to work from…(?)


#8

Basically, the slower the better. You’ll have to experiment on non-Proofgrade stuff, but try some speed values around 130-140-150 (and the appropriate power to match) and you should see much better results… no need to always run at max speed.


#9

:frowning: but I like ludicrous speed :slight_smile:

I was working in a similar way to the original advice above with full power and backing off on speed until cut-through but the power in the corners was still too much so now I have to look at speed and power. Production quality is paramount with cycle time coming in second. I was starting to put together some test runs when I decided to come look around the forum.

Thanks!