Hi,
it is far from certain what the problem is, there may in fact be two or three problems which are compounding things and
making it hard to diagnose.
You have bought yourself an ESS which is a good step to ensure good pulse streams to your BoB and stepper drivers,
yet the problem persists. It is not impossible that there is a problem with Mach/ESS/BoB but being able to eliminate
Mach/ESS/BoB altogether is the only real way to test the capability of the stepper/driver combination.
I suspect, but cannot be sure or prove, that the issue is with the steppers and drivers.
Electronics is my thing and I have a digital signal generator. Were this my installation I would drive the step input
of a driver direct from my signal generator. I could then be ABSOLUTELY certain that Mach/ESS/BoB have no part in the
test.
One of the challenges of testing steppers and their drivers is that it is not possible to just turn on the signal generator
and expect the stepper to be able to accelerate instantly. It is necessary to start the generator at a low frequency,
maybe a few Hz, and then increase the frequency taking note the frequency at which the steppers start to lose steps
or stall. The frequency at which the steppers stall is the uppermost limit that your steppers will perform. In a CNC machine
there will be loads induced by cutting forces and the torque necessary to accelerate the mass of the axes. Thus the ultimate
top speed that you have determined may be much less in practice.
Do you have access to a signal generator that could perform such a test?
The number of posts and the duration of this thread suggest to me that you must be getting very frustrated with the whole
thing. It might be time to enlist, even pay for, the help of a electronic technician. A stepper/driver test like this should not
require much more than half an hour for a technician. You really need to nail down where the fault is: either the stepper/driver
OR Mach/ESS/BoB.
Craig