View Full Version : Chinese laser accuracy problem

Levi Chanowitz
11-17-2011, 10:12 PM
My 60 watt rabbit never got to engrave very sharp letters. they are always a bit fussy. The outline is not to straight when I raster engrave.

IfI want it sharper I need to vector engrave the outine afterwards.
Does anyone know what I can do to increase the sharpness?

I have lasercut DSP4.1

Also, where is the best place to get lenses? What size is my rabbit lense?

Thanks for your help


Rodne Gold
11-17-2011, 11:07 PM
Check that your focus is accurate , also check your bidirectional tuning , ie that left and right strokes line up. The diameter of the lens is its size, most likely either 15 or 18mm. Its focal lenght would most likely be 50mm but it can be 40mm also , its the distance from the lens to the focus point , you need to measure it.

Levi Chanowitz
11-18-2011, 9:50 AM
Thanks Rodney. My focus is correct. What is bidirectional tuning? What do you mean the left and right strokes line up?
I also have a problem that when we draw a rectangle it is not 100% square and that the end and begining of a circle are a tad off

Rodne Gold
11-18-2011, 10:07 AM
Well the laser fires on the forward and backward stroke , and often the start point and end of each dont match
you want
and not
I dont use your software but there is a setting called tuning or bidir tuning or backlash compensation or a word like that that allows you to compensate and match the lines. You need a magnifying glass to check
But if you get the lines to match , you can raster 2x quicker and get sharper results.
There is also a setting in software or the driver to compensate for differences in X and Y motion so with the correction , squares are square. It will ask you to engrave a sq and put in actual measured sizes.
Circle end points not lining up can be machine innacuracy or the non square thing or slop in the motion system.
Your software might have a lead in/lead out function where you can start and end inside or outside the circle depending whether you cutting it out of a bigger piece or cutting it FROM a bigger piece, yoou can actually do this with any shape. Rather try solve it with accurate machine calibration and tightening up anything loose than do the lead in thing , it can be tiresome in very complex cutting plans.

Levi Chanowitz
11-18-2011, 11:30 AM
I cant find this at all in my LaserCut DSP 4.1 software, can I switch to your software? should I get a different driver?
Someone suggested that my machine may be mecanically calibrated wrong, and ifI loosened the setscrew from the motor drive belt, I could adjust it