Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: rodhead on August 14, 2009, 06:52:24 PM

Title: cnc driver board
Post by: rodhead on August 14, 2009, 06:52:24 PM
Hello

 I have my cnc router almost finished. I'm using mach 3. I have nema 23 277oz motors. can anyone tell me a goo 3 axis board and power supply for these? Thank you in advance
Title: Re: cnc driver board
Post by: Peter Homann on August 14, 2009, 07:07:00 PM
Hi,

Have a look at the Gecko 540. It is 4 axes so you will have a spare. It is a complete 4 axis system. Just add a power supply and you are done.

http://www.geckodrive.com/product.aspx?c=3&i=14469

Also Gecko is currently having a sale at the moment.

Cheers,

Peter.
Title: Re: cnc driver board
Post by: simpson36 on August 15, 2009, 08:26:41 AM
Gecko also sells the same drives individually as the G251, but you would then also need one of Peter's excellent Break Out Boards.

I don;t know if the 540 has any relays in it, but you would want to consider that to switch the spindle on and off. Peter's BOB had relays on it and you use those to swithc inexpensive AC relays to turn the spindle on and off.

What is the voltage spec on your motors? 4 wire or 8 wire?

There are different ways to wire up bipolar steppers. Make sure the low end Geckos have enough capacity for what you want to do.

The power can be switching type or unregulated for steppers, but remember that steppers should run many, many times their rated voltage. Read some of the excellent info on the Gecko site for sizing power supplies.

I first ran my 4V steppers at 36V and it was pretty lame and stalled easily. I switched to 72V and it was literally as if I had replaced the steppers with twice as powereful motors. No more stalling.
Title: Re: cnc driver board
Post by: rodhead on August 15, 2009, 10:53:21 AM
The voltage is 3.6 v. and 4 phase 3.0A. they have 6 wires.
Title: Re: cnc driver board
Post by: rodhead on August 15, 2009, 10:56:22 AM
Is the G251 only for one motor?
Title: Re: cnc driver board
Post by: ger21 on August 15, 2009, 04:12:24 PM
Is the G251 only for one motor?

Yes
Title: Re: cnc driver board
Post by: simpson36 on August 16, 2009, 07:05:21 AM
The voltage is 3.6 v. and 4 phase 3.0A. they have 6 wires.

In that case, you will be running them at 3.0A which is OK for the Gecko mentioned. If you go that way, I would suggest you get a 48V power supply.

My advise, however would be to run the steppers at 72V with Gecko 203Vs.   It's more money, but you will be a lot happier with the performance, especially if you rout wood and need the machine to move relatively quickly. Stepper power drops off scary quick as the speed comes up and the extra juice really helps them keep on truckin' so that you can keep the feed rate out of the 'burn the workpiece' range and hopefully never be plagued by lost steps and ruined parts.

Good luck with your project!