ESS/MB3 to control AC servo as spindle motor

Hi
I've just got a 1.8kw AC servo motor and driver that I'm going to control via the ESS/MB3 pairing. The control software is Mach4
The servo driver is a HLTNC T3DF unit.
Wondering if I just drive it with Step/Dir or is there a better way?
Cheers
Phil

This is how this is done:
https://www.cnc4pc.com/blog/post/con...tepper-and-c82

Check this out:
https://youtu.be/1cx5qVEXGrk

This will give you an idea: https://youtu.be/1cx5qVEXGrk

Arturo Duncan
https://cnc4pc.com

Hi,
I have a second hand 1.8kW Allen Bradley servo for a spindle. 99% of the time I use it in velocity mode, that is to say I give it an analog voltage 0V-10V and it spins from zero rpm to
3500rpm, the servos max. Easy. In this regard its very much like a VFD driven spindle or your KBIC driven spindle motor.

Velocity mode has the distinct advantage of simplicity but is actually better than you might think. In particular the servo speed (rpm) is controlled by a feedback loop, so that if the load increases
the servo digs in to maintain the commanded (analog voltage) speed. The spindle speed will stay within a few percent of commanded speed right up to the point of stalling.

Given that you have a servo you could alternately run it in position mode ie Step/Dir. Mach4 allows you to specify the spindle as Step/Dir or alternately you could use an Out-of-Band axis. Either will work.

The 1% of the time I use my servo spindle in Step/Dir is when I want to rigid tap. I do not use it as a free running spindle or an Out-of-Band axis but as a Caxis. This allows me to coordinate between the C axis
(ie tap rotation) and the other linear axes, the Z axis particularly. It works but I use it so infrequently that it really is just 'one of the possible things you can do' rather than a regular thing.

From the point of view of simplicity I would suggest running in free running velocity mode with the MB3 supplying the 0V-10V analog signal as you do now.

Craig

Thanks guys for the info
I think I'll head down the suggestion from joeaverage as I don't have the board outlined by arturod
Cheers
Phil

Hi,
I think you misunderstand.....you could use Step/Dir without any extra hardware, the MB3 has plenty to spare. None-the-less I think just programming the drive in velocity mode
is still simplest...and will get you going. If you want to experiment with position mode and Step/Dir in the future.

Craig

Hi,
Mach4 has 12 axes, six (X,Y,Z,A,B,C) are coordinated and six OB(Out-of-Band uncoordinated) axes, OB1 thru OB6. You might consider that Mach has one other motor output, namely a PWM output. The PWM output is usually used
for a spindle, say an analog controlled VFD or similar.

If you wish to use Step/Dir for a spindle then you have to use one of the OB axes. You might decide for instance that you wish to use OB1 as your spindle.

The first pic is of the Mach4 Control plugin, Axis Mapping Tab...where OB1 is assigned to Motor5. You could now set the properties of the motor.., like the pulses per rev etc in the Mach4 Control Motor5 Tab.
The second pic is the Mach4 Control Spindle Tab where you assign OB1 as your Step/Dir spindle axis. The Last pic is of the ESS plugin Spindle tab. Note you will need to assign ports and pins for the spindle servo
per normal in addition to this tab.

Craig

Thanks Craig.
I understand now.
Cheers
Phil