rigid tapping fail advice and "discriminant" err

yes

Here is the plot...

And here is my full config...

Looking at your plot, there's a huge position step, so that cannot work
(and probably what confuses the motion planner)

If you want to do rigid tapping I don't think you have many reasonable options except
a full quadrature encoder ( with A and B ) and index on the spindle.

PCW wrote: Looking at your plot, there's a huge position step, so that cannot work
(and probably what confuses the motion planner)

If you want to do rigid tapping I don't think you have many reasonable options except
a full quadrature encoder ( with A and B ) and index on the spindle.

Peter,
Isn't that just where the spindle reverses direction and Z begins to move back out? Why is that a huge position step? I guess I don't know what a successful graph of tapping should look like but I thought this looked ok. Is it not? Why is quadrature required?
-Tom

Here is what a normal threading graph would look like. Your config probably works great for single point threading - but the inverting of the position is bad for rigid tapping. (plus not having a quadrature encoder - your spindle reversals are not going to be accurate..