Hi Folks, I'm getting ready to cut some 1/8" cast acrylic and wanted to

Lasers
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Hi Folks,
I’m getting ready to cut some 1/8" cast acrylic and wanted to double check what settings you all are using.
What I found suggests 100% power at roughly 20mm/sec. How does that sound?

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I do 10mms @ 10mA

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@Ariel_Yahni_UniKpty Do you know how much 10mA is in terms of % power for PWM, or what mA 100% power is?

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Check +David Richards and I Laser’s post on April 24, 2016. He’s got a graph of power in mA vs. percentage.
https://plus.google.com/communities/118113483589382049502/s/power%2Fpercentage

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I setup my Pot to 10mA and then 100% there

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If you don’t know what your psu is outputting at 100% ma wise its probably a good plan to check. I’ve seen the psu’s in those put out 22ma at 100% with the dsp controller. Which is comfy for a 60w tube. Not a 30. 15 is really max if you want it to last a bit.

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The values that David Richard posted are consistent with values I’ve seen elsewhere.

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Great. I just finished modifying my Vectric Aspire postprocessor so that I can scale 1-100 spindle speeds down to 0-1 pwm values for smoothie and will be testing shortly.

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Ray, you got me on that last one of editing the post processor. What I’d like is a Gcode parser/editor that has tools that can modify existing Gcode. Scaling x, y and z or mapping the z to 0-1 pwm for just two examples that can help us modify existing CNC files. Seems like a natural for a gcode viewer to expose the structure of the file to editing.

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Just finished the first cuts. 40% pwm corresponds to 8.5mA on my machine. The needle jumps to 10 and then settles on 8.5. With air assist that was not enough to cut full through, I had to do 2 passes which was a spot on through cut.

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I’m not happy until I can do 1 pass

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Which I will be adjusting for in the next job… 80% power would do it, (more than 15 but less than 20mA) but I may go 60% and a slightly lower speed.

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What speed did you did on the last one

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10mm/sec like you said.

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I do 1/8 cast acrylic as my main project material, I’ve been running at 10mm/sec with roughly 12-15mA, that would be 90-100% on a PWM control. I agree with others that you should verify mA output at given percentages tube damage can occur.

I have air assist, which is almost a necessity with acrylic as it likes to flare up during cutting.

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I do 3mm acrylic at 10ma 6mm one pass. Though very dependant on your mirrors, lenses and smoke extraction.

I’ve whacked a multimeter on my machine and in my case readings are consistent with mA meter. YMMV