[Gnome]

I've been lurking around the forum for months now and have finally decided to cnc plunge. I am currently looking at retrofitting my Grizzly Mini-mill.

The motors that i have been looking at are from automation direct, they are 276 oz-in, bipolar, 2.8A/phase, 4 wire.

I have been looking at the xylotex 3 axis driver. I realise that this drive is limited to 2.5A so i will not get maximum amount of power from my motors. However, i'm hoping that it will still work.

My questions are:
1.)Will the motors that i have chosen be powerfull enough? (i realise that this depends on many factors, but in your own opinion)
2.)Will they work well (or at all for that matter) with the xylotex drive?
3.)Are there any other bipolar drives that would suit these motors better for around the same price (ie: except for geckos)
4.)What voltage power supply would be well suited for these motors? i have heard of the 10-20X voltage rule however im unable to find a voltage rating for these motors.
5.)Is it easy to wire home and limit switches with the xylotex board? what breakout board would you recommend?
6.)Are there any wiring diagrams around for the xylotex board, that show how to hook up the drive, breakout board, limits switchs etc.

Any comments and/or suggestions are very much appreciated.

[RotarySMP]

1/ Yes - I'd run them geared 2:1 with a timing belt, as it doubles the torque and avoids the requirement for perfect alignment. Amperage is holding torque, and the 10% drop in holding torque from 2.8A to 2.5A won't be noticeable.

2/ Yes - Not as well as they would driven at 60V and 2.8A from a Gecko, but well enough.

3/ I don't think so.

4/ The Xylotex is limited to 30V (or maybe 24V - check the web site) So that is your limit. This is going to be the big difference in performance to a Gecko at 60-70V. Voltage is speed, amperage is holding torque. Your rapids will be somewhere around half what a gecko at full voltage could provide. Then again it should still be adequate it is only a small machine.

5/ Have you checked the docs on the xylotex page? I am using an NC-Step opto board, but I'm in Europe.

6/ It is easier than you think. Just think it through one wire at a time, each motor has four wires that go to the Xylotex in pairs. Each xylotex gets a step and direction signal from the PC/break out board, and power and earth from the PSU. Any limit lines just get passed through the xylotex, or maybe go straight to the PC/ BOB. Make a wiring diagram as you go, it eases troubleshooting later.

Have fun.
Mark

[ger21]

3) You have to assemble it yourself, but you might want to check the boards from http://www.embeddedtronics.com
I *think* 3 amps and 50V?

[ViperTX]

Look at the stuff automationdirect has...take the coil resistance and multiply it by the rated current and you'll be in the ballpark on the coil voltage.

[kfong]

Hi Gnome,

If you solder and have some electronic experience. It would be easy to build up the controller.
http://www.embeddedtronics.com/microstep.html
and the
http://www.embeddedtronics.com/microsteppld.html

Both will work fine, the pld version is faster but you will need a very fast PC to make use of it.

The design is based on the National Semiconductor LMD18245 3amp 55volt full bridge motor driver. This is a very rugged chip capable of 6amp surges and has 12amp burst rating. For speed you want to go with as high a voltage as you can find. I would keep it under 50volts just so you have a window of error since most power supplies are not that well regulated. These drivers will work very well with your motors.

Kin

http://www.embeddedtronics.com/

[JFettig]

With those steppers and ballscrews with the xylotex kit, I would assume from how my mill ran with 300oz-in and gekos on 30v, I think youll probably get about 30ipm out of them, possibly up to 45ipm rapids.
Do you know what the voltage on those motors are? I ordered 2 of them for my lathe, should have arived today, but will come tomorow(snowstorm).

Jon

[JFettig]

I just got ahold of my motors yesterday and got them mounted on my lathe, I havent tested them but I took a look at the performance curve and I have to say that it is quite impressive.
These will outpower the 400oz-in motors that they sell running at 500rpm(400oz-in) running at 800-900rpm with the nema 23 motors. Either this performance curve is very impressive or the other motors curve is pretty sad.
What I do know is that these motors will probably work well, after I get mine up and running Ill let you know how they compare to my japan servo motors(300oz-in steppers)

Jon