GearHeads Forum

There is another way to smooth out the bumps you are encountering due to straight lines instead of curves. If you are using a CNC mill or laser that uses Gcode Be sure you are using G64 ( constant velocity mode instead of G61 (exact stop mode).
For those who are not well versed in Gcode here is the difference.
Most but not all programs that write Gcode use G61 as he default code.
What G61 does is cause the cutter movement to stop at the end of every straight line segment. If you have 50 segments in a curved line the cutter movement will stop and restart at the end of each line segment causing the problem you have encountered..
what G64 does is it keeps the cutter moving in a smooth cutting flow thereby eliminating the stuttering or jerky motion.
Dan

Dan:

  Good point, thats probably why I never notice the problem, the constant velocity does the job of smoothing the run so you dont notice it.

  I am working on a new module that also uses the toothing algorithsm for non-circular
object ( the math function gear module), so I will look at it when I get to the toothing code to see if I can antialias that section of the output.

Thx
Art

I agree with you Dan -- However, my problem is that I can't generate the G-code using my existing CNC CAM program in order to implement the G64 code.  In other words, my CNC-CAM program writes out a bad tool path when it encounters the "jaggies".

I do appreciate that you provided the information about the G64 code.

Art, thanks for looking into reprogramming Gearotic to eliminate the "jaggies"

You can jst add a constant velocity Gcode to the start of any program, you dont need any program to generate it, you just edit the ifle and add it to the top..
Is your system jittering on that section when cutting as it stands??


Art

Art,

The problem is that my CNC CAM problem will not write out the tool path for jagged gear path unless I smooth out the "jaggies".

Gary

Gary:

  Really? It just refuses to path that profile? Wow..

Have you tried generating the Gcode from Workbench instead?

Art

Art,

Yes, Workbench will output code  to cut the gear  --  However, I want to add additional features to the gear that Gearotic does not do.  (i.e. Art work, Fancy lettering, my own spokes, hubs, more detail. etc.).  Gearotic is excellent at creating the basic gears -- if only my CNC CAM program would cut the teeth properly.

Ahh, now I understand.

Ill make sure I get an antialias as soon as I can in the conext of what Im working on..

Thx
Art