Using DMM servo for spindle motor

[steelcogs]

I have a DMM .75KW AC servo motor on its way I plan on using for my spindle motor on my mill (The stock motor just can't roll with the punches). I see DMM is a known motor to work with the Masso, but for one of the movement axes. I'd like to use forward and reverse, and wire the encoder to give the Masso input on what the motor RPM is in reality (vs. just showing the programmed RPM) and be able to do rigid tapping. How would I wire this, as a 4th axis, or to the spindle inputs treating the driver as a VFD. I'll be using this driver with this motor and I plan to use a 1:1 pulley ratio and possibly in the future making a 1.5:1 ratio step pulley for more RPM on smaller tools that need more RPM and less power. I'd obviously have to tell my program to spin at 5000RPM if I want 7500RPM, etc.

Thanks

 

[testyourdesign]

@steelcogs there is some good information in the encoder help post from last week and on the documents page. Anything over 4800 rpm requires a modification to the MASSO opto couplers.

encoder-help

spindle-rpm-encoder

I hope to have the same setup as you described with my BLDC spindle motor. Just received my encoder last week and have basic connections started.

Cheers, Stephen Brown

Extended Masso Team Member ?

 

[masso-support]

The DMM motor needs to be wired just like a VFD in analog 0-10v control.

Regarding encoder output from DMM, please keep in mind that the pulse frequency from the encoder cant be more than MASSO requirments, please see this link: https://www.masso.com.au/docs/masso...on/setup-and-calibration/spindle-rpm-encoder/

Also as you mentioned about ratio on the spindle, if the encoder is on the motor then the RPM on the spindle and motor will be different, in that case you will need an encoder on the spindle.

 

[steelcogs]

Thanks for the info. I believe I can setup the pulse frequency and frankly too many other options with the DMM software so I imagine that shouldn't be an issue. Wiring 0-10v will allow me to run it in reverse too? I've only dealt with forward motion so that hasn't been a concern in the past.

As far as using anything other than a 1:1 ratio - I don't think I'll have any use for an encoder on the spindle. I'll know that with a 1.5:1 pulley ratio 5000RPM = 7500RPM at the spindle, 2000RPM = 3000RPM, etc. This would mainly be used for smaller tools (1/8" or less) and wouldn't likely be often. Making step pulleys is something down the road anyway. But again I just don't see myself needing an encoder for that, it's most important for tapping, which would not be anywhere near that high of RPM.