RE: [CAD_CAM_EDM_DRO] reprap build started

By "gcode interpreter/stepper driver" I meant the firmware that converts the GCode moves into realtime motor speed/motion control. This is where the acceleration handling should be, no need for custom hardware.
In the setup we are using, the acceleration is essentially managed by the skeining software playing with the F words on the G1 commands, with "help" from the obtuse implementation of said words by the FiveD GCode interpreter on the mainboard (which treats feed speed as a value to be interpolated like X and Y are, so a move starts at the last move's final feed speed, and accelerates/decelerates to the value in the F word of the current move). As a result, one must regenerate the GCode to change axis accelerations.

-Kevin Martin
the Papertrail Handmade Paper & Book Arts
New Dundee, Ontario
518-884-7123
www.papertrail.ca

-----Original Message-----
From: CAD_CAM_EDM_DRO@yahoogroups.com [mailto:CAD_CAM_EDM_DRO@yahoogroups.com] On Behalf Of Mike Payson

>
> Before going around replacing axis steppers with servos, a better approach would be to put the acceleration smarts into the gcode interpreter/stepper drivers, and make it possible to adjust these tuning parameters without having to build and load new firmware. Properly-tuned steppers could go a long way in curing (perceived or real) stepper performance problems.

Putting the smarts in the drivers would mean all custom drivers...
Certainly possible, but you would need to make a pretty compelling
argument to justify doubling or tripling the driver cost (the most
widely used reprap stepper driver costs $13).