Trying to slave the C axis to the Y axis. The problem I am running into is the C axis steps per is 2.25 times greater than Y axis steps per. I changed the C steps per in motor tuning but it keeps taking Y steps per since it is slaved to it. Is there any way to slave an axis to another and apply separate steps per values?
Thank you,
Beau

Mach3 will always send the same Steps per Unit to each axis in the slaved pair.

Would it be possible for you to change the microsteps setting for your C axis driver to make them 2.25 greater than the microsteps for your Y axis driver ?
I think it is doubtful, but if that could be done then the Steps per Unit could be adjusted to create the correct scale.

Mach4 can handle it with no problem.

I wonder how difficult it would be to update to mach 4 with our machine... Is there a lot of people who have done it? 

We've also had kind of a strange problem that when our machine accelerates during a feed-rate its fine, but de-acceleration is kind of clunky. It accelerates to speed well but when it slows down to stop its is not nearly as fluid and can come to an abrupt stop.  Never happens during rapid travel just during cutting or when a feed rate is applied. From what i've been experimenting with I have a feeling its something to do with the increments we are applying in the g-code but i wonder if we would have this issue with mach 4...

Hi,
in some respects Mach3 and Mach4 are very similar. If you have Gcode that causes 'clunks' in Mach3 then its entirely
likely that you would have the same clunks in Mach4.

Mach4 is pretty well developed, and in some area well ahead of Mach3 (Zero Brane editor and Surface Map are
two that come to mind). What Mach4 does require is an external motion controller. Mach4 does in fact have a
parallel port driver called Darwin ($25 licence fee applies) but it is not fully featured and I suspect you would
be disappointed with it. Mach4 was always intended to be complemented by an external motion controller like an
Ethernet SmoothStepper.

With a SmoothStepper (and one or more breakout boards like the c11 at $23 each) it would take several hours to
swap from Mach3 to Mach4. It can be a 'hairpulling' experience but can be done.

Craig