# Difference Between A Dc 'driver" & A Dc 'velocity Control Unit'?



## Bradrock (Jun 11, 2016)

The screw machine I bought has a Fanuc General Numeric GN3 control panel. The machine has Fanuc #5 DC servo motors with pulse coders. 108 volts 2000 rpm's.
I did not get any power supply's/drivers. I'm having zero luck trying to find out what all I need if I decide to put it back to original system.
Anyhow, while searching for Fanuc DC drivers, what I find are 'Velocity control units'
Are these actually DC 'drivers' or something different?
Every tid bit of info will be a great help to me.
Thank you,  Brad


----------



## countryguy (Jun 22, 2016)

It looks like 80's tech to me?   These guys should be able to talk intelligently and give you the "101" info you'll need.  http://cnc-electronics.com/product-category/fanuc-drives/velocity-control-unit/

I recently did a Supermax Mill w/ an old Allen-Bradly Bandit controller.  DC Servos, drives had been ripped out.  cords and wires everywhere... Ugg!  The encoders on the motors are probably low resolution, The tach-feedback stuff is ancient,  the power consumption excessive, the power supplies all old linear stuff, on and on.   I mean I get the desire. I was there once.   But-  I ended up putting in a Centroid AjaxCNC controller and have been nothing but happy I did.    I used the same ol' motors.  did a rip and replace on the old encoders and tach stuff.  Put on fresh high end encoders,  rewired everything so I know every inch of it.   This sounds like a heck of a project!!!!  Good luck.   

ps-  Some more pictures would really be cool to see this thing as-is.


----------



## Bradrock (Jun 22, 2016)

Thank you. Yes it is a 1982 machine.  I'm convinced I'll have to re fit to more modern electronics. Still would like to find out what the original Fanuc set up was though.
I have some pics on a couple other threads here.
http://www.hobby-machinist.com/thre...ew-old-traub-screw-machine.47687/#post-403060
http://www.hobby-machinist.com/threads/well-its-almost-in-my-shop.48026/

I will be posting some more soon.

Brad


----------

