What are your laser accels?

Hi folks,

I’m back to lasering small text on wood (each character is about 0.15"/4mm high), and I get this horrible squiggly lines when I use the Shapeoko’s default accels of 400mm/min on X and Y:

It could possibly be vibrations from my laser mount (I’ll redo that mount for less flex, later), however vertical and horizontal lines are quiet clean/straight:

I reduced accels to 100mm/min, got this:

And then reduced to 50mm/min and get a semi-decent result (where the defect is impossible to see to the naked eye)

I browsed a fair number of laser-related threads here and did not find any info as to what accels you guys are using when lasering, can you share your settings ? (or point me to previous threads I might have missed that would mention how to address these squiggly characters)

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I’ve gotten a bit of that wiggle on some small fast stuff I did with my diode laser with magnetic mount. It was a long while ago, so I don’t recall the settings, but I’m pretty sure it’s the mount bouncing around. It doesn’t take much flex to give some odd lines. Here’s what mine looked like, the engraving is pretty small, maybe 1 1/2” diameter:

Dan

I had seen that pic before but did not realize the wiggle in the center pattern was not intentional :slight_smile:
Do you remember if you had manually tweaked the accels or was this at the default Shapeoko setup values ?
I also tend to think it’s the mount, I think I’ll work on a custom mount that has a lower amount of lever from the X rail (and also reduce my speed, probably)

I never changed the default Lightburn values or the Grbl values, but I don’t recall my actual speed/power. You kinda have to zoom in, but those wavy lines should be smooth contours. Definitely think the mount wobbles. Probably don’t notice it on larger or slower moves, but those tiny details with a lot of quick direction changes show it for sure.

Dan

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Perhaps the “wiggle” is always there in the whole carriage and it just becomes more obvious with the finer cutting detail of the laser?

Pretty sure in my case it’s the actual laser mount, it’s a fair amount of mass cantilevered out on 3D printed plastic and magnets. Didn’t see that anomaly with my drag engraving bit on acrylic with the actual router either.

Dan

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Come to think of it, neither did I, and I did some pretty small engraving jobs with that diamong drag bit. Probably the mount, though in this case I am surprised to not see more reports about this, there is a fair number of shapeoko owners that bought the JTech laser and its plastic mount. My setup is probably a worst case scenario though, I am using a 3D-printed holding arm with magnets, which is itself bolted onto a 3D-printed frame mounted on the HDZ. I’m sure it must be flexing and twisting all over the place when changing direction.

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