Project at a halt!

[Tony611]

I have been gathering the electronics to build my own stepper motor control boards but found out that the L297 stepper motor chips are not compatible with the Mach3 cnc software. I am now contemplating using the Gecko G203 stepper motor controller. I have read a lot of different forums saying to use a micro step controller or a smooth motion controller. Are these two the same thing and where do the connect. So far this is how that I understand how the connections go. PC using a single or double parallel ports connect to breakout board, stepper motor controllers connect to breakout board, stepper motors to stepper motor controllers, limit switches to breakout board, home switches to breakout board, coolant pump to bob, e-stop to bob.

The components that I am considering are:
Gecko G203v stepper motor controllers
Mach3 control software
nema 23 370oz. motors
c23 dual port multifunction cnc board from CNC4PC

If I have misunderstood the connections or need to include something else, could someone let me know. Any help would be appreciated.
Tony611

[Crevice Reamer]

Hi Tony!

The components that I am considering are:
Gecko G203v stepper motor controllers
Mach3 control software
nema 23 370oz. motors
c23 dual port multifunction cnc board from CNC4PC

If I have misunderstood the connections or need to include something else, could someone let me know. Any help would be appreciated.
Tony611

Normal BOBs are connected to the computer parallel port. They cannot connect to a USB port because the step signals will lose their proper timing.

If you are referring to the Smooth Stepper, That is needed when your computer does not HAVE a parallel port. The Smooth Stepper enables CNC connection to a computer USB port.

You might be able to save several hundred dollars by using a G540 for drivers and BOB.

What kind and size of machine is this? What is the inductance and amperage of the motors? Why do you want a dual port BOB?

CR.

[H.O]

Hi Tony,
IMHO you'll be much better off with a set of G203V's than any L297/L298 based drive. Bu, with that being said, why do you say the L297 isn't compatible with Mach3? I have a set of L297/L298 drives that I designed myself many years ago and last time I tried them they worked fine with Mach3.

As CR says, if you're motors aren't big enough to require the G203's then the G540 looks like a very nice package, pretty much as close to plug-n-play that you can get.

/Henrik.

[Tony611]

CR and H.O thank you for your quick replies. I can't remember which web site or what forum that I was reading, but the author was commenting that the L297/L298 combo was not compatible with the Mach3 software. This is why I was lead to believe this.
As for the project at hand, it started out to be controls for a gantry style router. But due to the fact that my garage is now packed full of stuff ,that my wife has aquired, I have had to postpone the router project. I still want to do a cnc project so I have decided to retrofit my Jet 1325BD lathe instead. This is why I chose the G203's. They come in a version that has CW/CCW inputs that I am assuming are suitable for a lathe. I found some nema 23 370 oz/inch motors (#RS23-370) on the www.homeshopcnc.com web site. They also offer a discount if you buy a controller/motor combo. The c23 dual port cnc board was used on the cnc mill retrofit on the www.hossmachine.com web site and I thought that it would be good for my project as well.
Once again, thank you for your help.
Tony

[H.O]

Hi Tony,
The G203's are nice units - not that I have any but I have a set of G201's almost 10 years old and they're still going strong. If you're going to run such "small" motors then you might concider the G540. That will get you as close to plug-n-play as possible and you won't need a dedicated breakoutboard since the G540 already features the functions of that most break-out-board has.

You get a G540 (which has 4 drives and a break-out-board) for the same price as two G203's. The G203's will give you slightly better performance but it might be worth to concider.

If you want to use Mach3 (or any PC-based CNC control program) you definetely want the "standard" Step & Direction as the interface on the drive. I don't know of any software that outputs CW/CCW pulses. (Just out of curiosity, what's your reasoning on a CW/CCW interface being suitable for a lathe?)

/Henrik.

[Crevice Reamer]

Hi Tony.

I DO own G203Vs (And ALSO G540) You will DEFINITELY be better off with the G540. It will be your best and least costly solution--I know, it's a 4 axis driver, but in YOUR case, just consider it a low cost excellent plug-and-play driver/BOB--with two free spare drives.

It's tiny, so you can mount it anywhere, and it is in-effect, a small bunch of G203Vs. It comes WITH the Db25 connectors you will need to make motor cables.

However, the motors you have picked are NOT a good match for G540. They are 5A 40V, and when limited to the G540s 3.5A will only produce 260 ounces of torque.

This is what I recommend that you use:

$299 G540 http://geckodrive.com/product.aspx?c=3&i=14469
$098 Two KL23H284-35-4B 387 Oz.
$060 KL-350-48 PSU
-------
$457 Total cost.
You can buy all of this, including a $10 Estop switch and helical couplers, from Keling:

http://kelinginc.net/

CR.

[Tony611]

Hi H.O,
You say that these are small motors. Would they be too small for this project? If you go to www.cpojettools.com and look at the BDB 1340A you can get an idea of the size of machine that I am retrofitting. I am currently using carbide inserts (WNMG) for turning HSS cutoff blades for grooving and parting, HSS drill bits, and carbide inserted boring bars. As for cutting depth I have been taking a .050 depth of cut at .006 per. Rev. feed on a 2.0 inch dia. of 1141 mild steel with no problem. I would like to be able to still do this after the retrofit. This is why I have the question about the motor size. Now for the CW/CCW. I was assuming that it was need for controlling spindle direction so if I wanted to do some power tapping. Evidentially I have a lot to learn about cnc retrofits. But that’s ok, because that’s half of the fun.
Tony

[Crevice Reamer]

Okay. I was going by the motors you had picked out. I guess I should have looked more closely at the lathe. Forget the G540! Here's what I recommend for that size lathe:

$278 Two G203Vs
$049 One KL23H284-35-4B N23 387 for X axis.
$089 One KL34H280-60-4B N34 640 for Z axis.
$189 KL-6515 or $139 KL-5413 or $129 KL5010 PSU.

You will still need a breakout board. The KL6515 will also supply power for that BOB.

CR.

[H.O]

Hi Tony,
That's a fairly large machine, listen to CR's advice and go for the G203 and larger motors, I think you'll need it. Then, as always, it's a matter of how you gear the motors, what ballscrews you use etc etc, it's a lot to concider but alrger motors will definetly help.

Regarding the CW/CCW...you won't run the spindle with a step motor will you? ;-)

[Tony611]

H.O
I will be using the 2hp motor that came with the machine for now. I am hoping to use a vfd motor once I get the stepper motors up and runnig.
I still need to research the vfd systems to find out what is involved to install one.