Re: [CAD_CAM_EDM_DRO] EMC questions

ajv2803959 wrote:

> Hi, I am trying to configure EMC in order to get maximimun speed in
> rapids with my hardware.
> So on, this is my configuration Soft and Hard.
>
> Soft
> EMC 2.1.1.16, rtlinux-3.0 and Red Hat 6.2 (kernel 2.2.18),
> Kernel is patched and EMC is compiled without problems, It works well.
> PC is pentium II 233 with 32 Mgas de RAM
> Hard
> Chopper drivers with L297 L298 combo, wiht current idle
> reduction (SD1V1.2)
> Parallel interface DB1V1.2
> Hard was bougth from Deans Hobby CNC
> (http://plaza.powersurfr.com/deanc/)
>
> Below is the ini file that I am triying to make work.
> ; EMC controller parameters for switchless minimill.
> ; See genedit.ini for full descriptions and alternate values
> ; Trajectory planner section -----------------------------------------
> ---------
> [TRAJ]
>
> AXES = 3
> COORDINATES = X Y Z
> HOME = 0 0 0
> LINEAR_UNITS = 1.000000
> ANGULAR_UNITS = 1.0
> CYCLE_TIME = 0.010
> DEFAULT_VELOCITY = 1.0
> MAX_VELOCITY = 66.0
> DEFAULT_ACCELERATION = 20.0
> MAX_ACCELERATION = 20.0

Here's your problem. This acceleration is almost certainly too high for
a small stepper system. Try cutting it in half, or even a quarter. Find
the maximum speed you can move at with little acceleration. Then,
turn up, the acceleration a little at a time until you find the maximum
acceleration your motors can handle. then, back off each of these
parameters about 25%, and you should have reliable operation.

> ; Axes sections ------------------------------------------------------
> ---------
>
> ; First axis
> [AXIS_0]
>
> TYPE = LINEAR
> UNITS = 1.000000
> HOME = 0.000
> MAX_VELOCITY = 22

Note this will be 22 mm/Sec in your system, which may still be too fast
for your steppers and driver.

Jon