F1rst Post!

Ok, I currently own a Labvolt 5300 lathe and want to get it to work with EMC2. The problem is that it uses rs232 and proprietary commands that I don't want to deal with. SO, I am willing to create my own controller for it that is compatible with emc, but I need help knowing where to start.

It has 2 stepper motors and individual controller boards for each (pictured) and I am currently trying to figure out how the spindle drive works (PWM?). Any ideas on where to start with building an interface for parallel?

It looks like the chip on the left (on the chopper drive) is an SGS Thompson L297 stepper controller. You could look for info on the web about this chip and then trace down the step and direction control pins for it. With that info, you could run lines from your parallel port and bypass all the RS232 stuff. I've done this before on a Parker motion control box.
There should be loads of info on the L297 online. If you don't find what you need, let me know.

Dan

You might also check with this guy (http://www.cnczone.com/forums/showthread.php?t=21320). He's trying to buy a couple of the drives you have, if you are interested in retrofitting new drives, but he might also have some info on them.

Alan

It looks like SW2-2 is for full step or half step mode.
It appears that SW2 4-7??8 could be for setting the power out level?
I would check to see if J2 is logic power input.
It looks likely that J3 has two pins for motor power in and two pins for a fuse connection. It looks like J4 is the output to the stepper coils.
And that would leave J1 as a probable connector for step, dir, gnd and ???

I can't guarantee these but from the names and positions they seem likely.

Alan

J1 was hooked up to the original controller, J2 was unused, j3 was power and fuse, and J4 went to the motor.

How would the actual interface for the computer hook up? How would I build the circuit for that part?

After a closer look at J1, there are letters going down the side.

(from the top)
D
C
-
+

After a closer look at J1, there are letters going down the side.

(from the top)
D
C
-
+

Plus and minus are likely the logic supply power input pins. Get a data sheet for the L297 and check the pinouts. Then use a VOM to check for where they are connected (if you can't just see the traces). Pin 2 (L297) is gnd and pin 12 is logic power (5v).

Actually I am attaching a L297 datasheet. Pin17 is labeled CW/CCW (that is direction). Pin 18 is labeled clock (that is step). So find which pins on J1 are connected to 17 and 18 then you will have identified your step and dir signals. I would guess that D=direction and C=clock.

Next you should get an optically isolated breakout board that you can use to interface the parallel port to the step and dir signals (along with your limits and other controls).

Alan

I traced it and pin 17 is direction (D) and I wasn't able to visually trace (C) but it does appear to go to clock as expected.

Would you recommend any specific opto-isolated board for this? or should I just build my own...

I traced it and pin 17 is direction (D) and I wasn't able to visually trace (C) but it does appear to go to clock as expected.

Would you recommend any specific opto-isolated board for this? or should I just build my own...

I personally have used the CandCNC mini-IO BOB but there are a number of boards and preferences around. I have read of several people using Arturo Duncan's C11G, Robert Cambell sells a board from Sound Logic by Jim Cullin, one of the partners in CandCNC.

Do you have a volt/ohm meter? If so, you could check for 0 ohms between pin 17 and the pin labeled 'C'.

Alan