[Marty_Escarcega]

I have a Ganesh Knee mill. It currently has a Mitutoyo Millstar III control on it. It uses Glentek SMA7115 analog servo amplifiers. They use unregulated/rectified 120VAC input. The drives themselves are rated 15A continuous/25A peak @ 30-220VDC. The DC Brush servo motors are Glentek GM4020-39 and are rated at 1.28HP/.995KW, 6.6A Continuous Stall Rating. They do have tachs on them. Feedback is through an encoder on the Z axis servo and Mitutoyo glass scales on X&Y. The original motion controller is a Galil DMC1020. So there must be a board that converts the signals from the glass scales to quadrature input for it.

Mill and Millstar control are mint. I was trying to find a step/dir to Analog converter, that would have been my first choice. I am unsure why these are not more prevalent. My next choice was to find DC Brush Servo Amps that will replace the existing Glentek servo amplifiers.

I see the Viper 200 seems to just be at the top of the voltage range.

Larry, your thoughts on which drive I should choose? I also see you have a new Viper 250.

I guess some of my trepidation is tuning the servo motors once converted. I'm not afraid of doing the actual conversion, I recently converted a Dyna DM4400 with ATC and its up and running, though it took me a year of weekends! My control of choice will be a Flashcut CNC USB signal generator which outputs step and direction


Thanks in advance,
Marty
Mesa, AZ

[Larken]

Rectified 120V will give you 170 volts DC. This is still in the range for the Viper 200. As long as the motor is a size 42 or smaller (under 5" in diameter) , there should be no problem.
The viper 400 is a few months away, but coming (really) . It will be available with as an analog drive version as well as a step/dir version.

I've heard good things about flashcut. Can it do a ATC ?

Larry K

[Marty_Escarcega]

Larry, thanks for the reply. Yes, Flashcut can handle an ATC. Either driven by a stepper or servo or a geneva mechanism. I retrofitted a Dyna Mechtronics DM4400 with 10 position ATC. (Do a search on YouTube of DM4400 and you will find my machine)
The support is great and they can do custom macros and engineering for a fee of course.

I like the software. control itself is pretty straight forward. 5 axis capable and outputs step and direction. The servo amplifier closes the loop.
I really wished I could find a vendor that can take step and direction inputs, encoder input and output analog +/- 0-10VDC. My machine is like new and the Glentek servo amps are matched up to the Glentek DC brush servos.

Any reason why you haven't done a multi axis board like that?

Thanks Larry,
Marty
Mesa, AZ

[Marty_Escarcega]

Larry,
How difficult is it to tune the servo motors? My Glentek motors are 4" in diameter and are 180VDC motors.

[Larken]

You download Vipertune off a page in this forum, and its easy as long as you read the pages manual on tuning and understand what you are doing. Compared to other drives the feed back i get from customers would say its easy to tune.