View Full Version : Help! Stepper control board

26-05-2009, 10:05 PM
Hi All
I need some help please. Im trying to reuse the control board from the machine that I got the motors from to use on the drill/mill conversion and to get some cnc experience.

Im keen to reuse it because it appears to be good quality (german) and when it was running I couldnt stop the motors by hand so seems to be powerful.


The circuit is a common design, it uses a L297 contoller and L6203 amp section then ultra fast diodes on the output. but then it seems to go into a relay bank before the output which is confusing me, As i understand steppers are driven by controlling current? Is this working at full power all the time then? and as the relays are 5amp dose the meant i can run a bigger motor for the Z axis?

Input shouldnt be a problem as I think i can remove the optoisolators (3 white chips lower left) and tap into the drive section direct.

Cheers for any help

26-05-2009, 10:30 PM
I can only imagine the relays are to switch over to a different motor (or possibly to disconnect the motor to allow it to turn freely?)

26-05-2009, 10:37 PM
Ah. that would make sense. the machine was a meat slicer so maybe they are as a safety feature. have to trace the coil tracks and see where they go. Could make a good Estop!

Thanks Bill your a star :beer:
Any thoughts on the collet issue i mentioned in my other post?

27-05-2009, 04:04 PM
I think Bill means to turn freely once the electricity is turned off,,,back EMF?

Either on or off; The motor will not spin freely while connected to the protection diodes.

27-05-2009, 04:28 PM
I have a similar board...if the motor is disconnected while power is applied... :finger across neck smiley: :(

Kills the driver ? - sounds like poor protection design

Anyway what I meant was: with the power off the motor... With the power on it'll be locked up anyway.

27-05-2009, 08:18 PM
Im thinking that this is a great site and glad i posted.

Is there anything that you two dont know?

Kip, the board dosnt accept step dir. as it is a self contained unit run by the PIC chip (i think) at the bottom centre of the board. Which bits did you want picture of? driver or control section?

However the two circuits are split with a optoisolator which I was hoping to remove and tap directly in the driver section which dose accept step dir. however it looks like Ive got some work to do on the relay side as well if these are also contolled by the PIC.

Cant wait to get started on this - 2 weeks to go

28-05-2009, 12:39 AM
I just finished testing my Phytron drivers.... Bought the drivers and motors for a meagre some a couple of years ago......Some great features...Adjustable boost, stop current, accel ramping etc....no switches all from the menu.

That looks serious! :eek: is it stepper or servo? didnt know you could get that much control with steppers if it is.

Any good with servo systems? ive got an old 4axis delta tau system that I need sorting out (setting up the amps)

28-05-2009, 01:08 AM
9 amp? I Bet the national grid love you. What is that going to control?

It's for steppers 9A max...set for 6 to the N34 motors (Phytron IP54 ones) No experience of Delta Tau...sorry.

No worries, fink im just gunna have to plug it in an hope it dosnt go bang:redface:

When are you going to finnish your router then? cant wait to see it working

John S
28-05-2009, 01:30 AM
9 amp? I Bet the national grid love you. What is that going to control?

Got some Bosch drivers here 530 volts at 52 amps, do you reckon I can TiG weld with these at 8 metres a minute ? :heehee:


28-05-2009, 01:31 AM
I was hoping to have the router finished this week....other commitments are keeping me busy.....
Tell me about it not enougth days in the week etc.......

Does castration hurt? thats what I'm getting apparently the next speck of silver stuff that hits the axminster....

Depends on the method I suppose, Sharp knife or two rocks :surprised:
So that why your machines look so good, there indoors! mind you if I could get away with it thats where mine would be :smile:

28-05-2009, 01:42 AM
Got some Bosch drivers here 530 volts at 52 amps, do you reckon I can TiG weld with these at 8 metres a minute ? :heehee:

Ok perphaps 9 amp is that much then :redface: dont know how to tig weld so cant help im afraid ;o)