Messages

1161

General Mach Discussion / Re: Help on wiring an E-stop in.

« on: May 06, 2009, 10:31:26 AM »

Hi Michael,

I've been through this recently as well. The correct way to wire the Estop is such that it would cut off the power to all the motors of your machine. Also, it is not a good idea to cut the AC side of the of the motor power supply. You have to cut the DC side and switch in a power resistor to discharge the capacitor.

Also it is a good idea to notify Mach3 when Estop has been hit. So in my setup the Estop also cuts the 5V going to the BOB enable terminal, which is hooked to pin 10 of the PP.

Daniel

1162

General Mach Discussion / Re: Any one used xylotex boards to upgrade an EMCO lathe?

« on: May 05, 2009, 01:31:00 AM »

Hi Jack,

I don't think you'll be able to drive the stock motors with the G540. As far as I remember, the G540 is only 50V. Not enough for the factory motors (if they are 9V indeed, like mine were).

Daniel

1163

General Mach Discussion / Re: Any one used xylotex boards to upgrade an EMCO lathe?

« on: May 02, 2009, 02:35:44 PM »

The simple fact is that voltage equates to speed with steppers, and the Xylotex board with its 24v useful limit is just slow. With the Gecko 251s available (they were not when I started the project) I see no reason to ever buy a Xylotex board.

Ron,

Didn't realize the Xylotex was only 24V. Thought it had an upper limit of 35V. 24V sounds really low indeed.

Daniel

1164

General Mach Discussion / Re: Any one used xylotex boards to upgrade an EMCO lathe?

« on: May 02, 2009, 02:33:31 PM »

Chances are that the engineers spent a lot of time matching those motors to the machine.

Jeff,

You are not familiar with this particular Emco lathe Saying that the engineers spent time on constructing this machine is over complementing them. Actually, for this machine, over complementing would be even saying that "engineers designed it" The mechanical design of this machine is so awful that it makes me wonder whether it was a dumb engineer who designed it or a warehouseman.

However, about the stepper motors in particular you might be right about this machine. They seemed to be critically suited for the job, though I didn't work much with the original setup. The factory steppers on the Compact 5 CNC were 60 Oz-in, but I think (although, as I said, they may be just powerful enough) that twice that would be more appropriate for this machine.

Just my thought.

Daniel

1165

General Mach Discussion / Re: Any one used xylotex boards to upgrade an EMCO lathe?

« on: May 02, 2009, 09:25:39 AM »

So did you have to get a board to hook the motors to and then the board plugs into the parallel port on the computer?

Don't know what you mean by "board". My steppers are hooked to Gecko drives which in turn are hooked to a CNC4PC break out board, and this is connected to the LPT.

Ron, I think your motors where just rated too high a voltage. I think if you had 2V motors, you would have gotten acceptable performance. I have Mechatronics drive  (much like the Xylotex and rated the same voltage) on my F1 mill, and the rapids are at 1400mm/min - almost twice the original rapid speed.

Daniel

1166

General Mach Discussion / Re: Any one used xylotex boards to upgrade an EMCO lathe?

« on: May 01, 2009, 03:16:13 PM »

Oh... and you might want to have a look at this manual from GeckoDrive

http://geckodrive.com/upload/Step_motor_basics.pdf

It is a pretty comprehensive manual on stepper motors.

And as a correction to my previous post - the stepper driver's voltage should be 10-25 times the stepper motor rated voltage.

Daniel

1167

General Mach Discussion / Re: Any one used xylotex boards to upgrade an EMCO lathe?

« on: May 01, 2009, 03:01:16 PM »

Jack,

No, they don't have to be 9V. Actually the lower the voltage the better. Since the Xylotex is 35V, and it is recommended that the drive be about 5-10 times higher voltage than the motors, I'd recommend motors rated about 2V or less. But you'll have to make sure the Xylotex will be able to handle the motor's current.

There are really lots of vendors out there. I got mine form KelingInc.net . They offer pretty good motors inexpensively.

I use Mach3 on the lathe.


Daniel

1168

General Mach Discussion / Re: Any one used xylotex boards to upgrade an EMCO lathe?

« on: May 01, 2009, 02:11:30 PM »

Hi Jack,

What is the lathe model you have in particular? I have a Compact 5 CNC and I know that this whole series had variable reluctance 72 steps/rev stepper motors. If I remember correctly they are rated at 9V. The Xylotex driver can't drive them.

Get new, modern stepper motors to replace the stock ones and you should be fine.

Daniel

1169

Show"N"Tell ( Your Machines) / Re: My new CNC mill. JEH Guitars

« on: April 29, 2009, 03:47:42 PM »

Jens,

I see your point about the ball screws. At least I hope you have mounted wipers on them....?

Daniel

1170

G-Code, CAD, and CAM discussions / Re: GCode Scaling in Mach3 Turn

« on: April 28, 2009, 02:56:51 PM »

Hi,

You can use G51 X--- Z--- I--- J---  - fill in the scale factors for each parameter. Use G50 to reset all scale factors to 1. Read the manual to learn more about implementing G51.

Daniel