Servo Spindle motor encoder Mesa 7i76e

975 is a very odd number so I suspect something is still wrong

The 7I76E encoder jumpering must match the electrical interface on the encoder
Differential encoder interfaces will have 6 signals instead of 3:

Differential:

A, /A B, /B Z, /Z

TTL/single ended:

A,B,Z

PCW wrote: 975 is a very odd number so I suspect something is still wrong

The 7I76E encoder jumpering must match the electrical interface on the encoder
Differential encoder interfaces will have 6 signals instead of 3:

Differential:

A, /A B, /B Z, /Z

TTL/single ended:

A,B,Z

oke, well that confirms that the jumpers are right.

i set the encoder scale in my .ini file back to 1024. in program run its wait for spindle reach.

this is really weird what cause this.

To check if its a bad encoder, you could rotate at a constant speed and plot the
encoder velocity with HALScope. A bad /dirty encoder wheel will show up as a repeating dip in velocity

PCW wrote: To check if its a bad encoder, you could rotate at a constant speed and plot the
encoder velocity with HALScope. A bad /dirty encoder wheel will show up as a repeating dip in velocity

Found it!

Nothing in linuxcnc or drivers.

There is a difference in the poly v belt wheels. A deviation of 5%
I get the same offset in the drive. So i was questioning my self why also the drive counts where off.

Now, I might add a encoder on the spindle its self (as it was original but one puls).
I would like to have also a quadrature encoder on it, so i can also ridgit tap.

Or, i replace the v belt wheels to timing belt. Might be more work, but then i can use the servo motor as i intended.

Any suggestions?

Timing belts.
I would not try tapping with a V belt.

Erikcnc wrote: There is a difference in the poly v belt wheels. A deviation of 5%

That will do it. Successive index pulses will have a different relationship to the spindle position, so multi-pass threading can't work.

You could probably make it work by:
1) Adjust the scaling to be as close as possible, over 30 turns of thread the error is likely to be small.
2) Use a separate index that is not related to the encoder but is from a sensor on the spindle. A hole drilled in the main spindle drive pulley, as an example.