SOLVED: CSS G96 with CCW spindle M4 on lathe

Good evening,

G96 constant surface speed on my lathe works fine with CW spindle movement. Now I want to use an upside down parting tool with CCW spindle rotation.

But the x-axis does not move. It works with M3 instead M4. Gmoccapy shows correct -350 rpm (minus!) during M4. I assume, that feed does not start because it waits for positive spindle speed.

Do I realy have to use a separate HAL file with negated spindle feedback?

Best regards,

Hartmut

It may be possible to work around this by using some hal trickery:

A scale component and mux component to change the scale from 1 to -1
when desired.

But I do not know what LinuxCNC motion component expects.
It seems odd that a negative spindle speed would not be acceptable
for g96 when m4 is in effect.
 

Thank you.

I found out, that the in my spindle-at-speed detection I used the absolute value instead of the signed value. So I only changed
to and it worked.

Hartmut

That's even better!