Hi Guys
Any idea what might be causing this roundess in my test cuts?
The two axises have been calibrated to 0.1mm accuracy
I am using grbl 0.9j with a G-shield–Laserwbe3 is used to generate the G-Code.
In the attached photo you can see that the corners are rounded and that there appears to be a convex line on each edge where their should be a straight line
The G-Code File is here
https://drive.google.com/open?id=0B8pvPiWhMwS9YXQ5VzRCRHhYdVk
The photo is here
https://drive.google.com/file/d/0B8pvPiWhMwS9VEl4LTctdmJaSmM/view?usp=sharing
I am interested to here what you guys think!
Can you share the file used to generate the gcode and a screen capture of the preview in Laserweb?
gcode is fine, just tested it. At what speed did you run the cut?
My only thougth at this point would be to much heat at the corner due to very slow speed. File and gcode seems fine
Interesting point! . I shall a faster cut
Just did a test cut at 20mm’s and I notice, that when viewed from the side the beam appears to have cut at an angle… The bottom of the wood had the same curved edges but when I looked at the top of the cut the edge where straight.
Initial problem ==Solved! =P
New Problem!
How do I get the beam to cut straight…Could this prehaps be an issue with bed height…Maybe an more unfocused beam is hitting the wood in the wrong place
ok that means the head itself is at an angle. The gantry / head must be as close as perpendicular to the cutting surface. Inspect and measure at different point to find whats causing the angle
Ok Will Do… Should I make test cuts at differents points on the Y axis to see if the angle changes?
Really not needed, if the angle is very steep then you should easily see where the problem is. At the end the gantry/head and the bed/produxt being cut must be parallel to each other
Ah I understand now. Thanks for your help!
Just did some more tests. Cuts weren’t nearly as angled. Curves are still there. Did the g-code file cut straight on your machine?
I did not run the actual cut since by just inspecting the gcode I see straight movement with no arcs
Ah shame. I might try different materials to see if its the plywood causing an issue
Also I will try making the cut over several passes maybe that will reduce the warping (probably not =P)
If you don’t have air assist then to much heat will burn the wood faster, corners at slow speed can easily cause that. Try the same at much faster speed but multiple passes it should not see change in tone on the surface of the wood. I can try your file if it’s makes you happy 
Nah it’s fine. Thanks though. It is probably like you said due to the material burning too fast