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Mach 3 Laser Engraving

PostPosted: Thu Aug 11, 2011 10:39 pm
by gavztheouch
I have installed the engraving plugin for mach3. I have been getting double images, maybe 10mm apart instead of just one. Any ideas?

Re: Mach 3 Laser Engraving

PostPosted: Fri Aug 12, 2011 2:47 am
by naPS
I had this issue when I had the X axis speed set too high, and wasn't properly setting the addon up right using the calculate command. Are you using Tweakies version of the plugin?

Also, are you set up at 25khz? Or something higher? It also does that if you have it set higher sometimes.

Re: Mach 3 Laser Engraving

PostPosted: Fri Aug 12, 2011 10:41 pm
by gavztheouch
I download a version from a post tweake made, but i dont think its the one he specificly moddifed if that does exists. Other than that i have tried all your suggestions
with no luck. Have you had a similer problem?

Re: Mach 3 Laser Engraving

PostPosted: Fri Aug 12, 2011 10:56 pm
by naPS
http://www.machsupport.com/forum/index. ... #msg131346

There's his new version of the plugin.

And yes, I had the same issue. It was basically ghosting another image. I believe you probably have your steps per inch configured incorrectly, or some other problem related to your x-axis.

I followed the guide in his instructions, set the kernel speed to 25k, upped the steps per inch to 4,000, slowed the x-axis travel in the plugin down to 100ipm, and made sure I had the x and y dpi settings line up. The new version of the plugin calculates the dpi settings for you. Try following the guide in that thread, and that should help.

I'm fairly certain that's all I did to make it work. If you look in the original thread under the impact engraving thing, there's some troubleshooting advice in there as well.

Here's his document : http://www.cooperman.talktalk.net/Engraving.pdf

Re: Mach 3 Laser Engraving

PostPosted: Sat Aug 13, 2011 10:50 am
by gavztheouch
Thanks for your help naPS, I have looked through the thread you posted on the mach 3 forum. There is a case similer to mine where there was a delay in the laser activating, unfortunately all the solution don't fix my specific problem. Im using bart laser interface pcb, I now have my laser set to fire at active low, Its a fairly fast machine two 3.6 ghz xeon single cores. Here is a picture of the results with a test piece. The original image was a black rectangle on a white background so the image is split into three equal and straight edged areas going white, black, white.


Image

Re: Mach 3 Laser Engraving

PostPosted: Sat Aug 13, 2011 4:21 pm
by naPS
Can you take a screenshot of your setup screen for the engraving plugin? Can you take it basically right before you would hit the Start button to start the engrave? I'd like to take a peek at your parameters.

Also, what steps per inch are you using?

Re: Mach 3 Laser Engraving

PostPosted: Sun Aug 14, 2011 10:40 am
by gavztheouch
Image

Here is a screen shot of my setup just before engraving, im using a step per inch of 100 (this may be in mm?)

Re: Mach 3 Laser Engraving

PostPosted: Sun Aug 14, 2011 5:25 pm
by naPS
Try nudging your stepover down to like .1 or so, that should put it closer in line with the actual laser point width.

Also, try bumping your speed up a bit, possibly double of what you have right now. Everything else looks pretty good.

Also, are you sure your steps / mm are correct in both the X and Y directions? Have you tried running the head back and forth in both directions to make sure it's giving your accurate results? Have you cut and measured a test pattern in vector to see if your laser is calibrated?

Re: Mach 3 Laser Engraving

PostPosted: Wed Aug 17, 2011 11:33 pm
by gavztheouch
A few more observations. Once slowed down to 500mm/min you can see the steppers are pausing at the end of each stoke, but the laser remains on. It looks like the steppers and laser are out of sync. Im defining a stroke as a line of pixel. These strokes are not always on the same line, as you can see in the photo the end of a stroke is in the line above. This means the motors stop briefly in the middle of the pic with the laser still turned on, leaving a little black dot.

Is it possible the interface board is causing the delay, i may have a version that is inconpatible with engraving. Does it mess with the port signals? Im using pin #17.

I have gone to a fresh install of windows xp to eliminate any conflicting programs.

Re: Mach 3 Laser Engraving

PostPosted: Wed Aug 17, 2011 11:36 pm
by gavztheouch
Re: the stroke length and finishing in the line above, it has not happened in the picture above.