bandit controller retrofit

``if you want max torque but lower rotation speed, use the two wires with most resistance, in your case use A1/A2 and B1/B2 and leave ACOM/BCOM unconnected``
Thanks a lot Tom, will check first, exactly what you said, that is how i wanted to connect.

The 3 bottom wires on the drive boards, what do they have written ?
Do you have an old PC with parallel port?
If those wires are step/dir and GND, fire up the PC, wire some wires from parallel port to those 3 wires, move the machine!

I don't think they are, but I'll check, I think the ones from each driver go to the ``estop'' system of the machine or to the end switches, something like that... the signals are in this flat ribbon cable, but who knows what they are, maybe some older control system, some ttl something, I wouldn't know how to check that without schematic , and I couldn't find a schematic for this driver, the controller is from the 70s.

To the left of the ribbon cable, are those optocouplers?
If yes, see what wires go to those optos inputs, those should be step, dir, and maybe enable, one is ground, and for testing you only need 1, the step pin, and if used the enable, but if the drives lock when powered on, then skip enable as they are enabled, so use a signal generator or parallel port, or a small crappy transformer that outputs 3 to 6V AC, should be enough to check if they work, and if they do, leave them on.
Be aware that some older drives use two inputs as step and have no dir at all, so steps on one pin turn the motor one direction, while steps on other pin move motor the other direction.
There are also "quadrature inputs" using steps on both pins, but 90 degrees between them, also no dir.
And as the last type, the 4 input ones, so when testing if the motor does not turn but just vibrates in place, check other pins, there should be 4 that cause the motor to vibrate.
All of those can be controlled by LinuxCNC, even through a parallel port, hence my hesitation to change the drives.
But if you think the time is more valuable, do change them.
And if the motors turn out to be 5 wire ones, they can be changed to bipolar, just require a bit of time and a soldering iron.
BTW, never ever remove the rotor from the stator on stepper motors, that will render them useless as they will de-magnetize.

The flat control cable from the driver's controller has 16 pins, I shouldn't try it because I'm afraid that there will be some ``smoke signal''

...except, a friend will lend me a hand-held oscilloscope, where I could establish by moving the jog buttons on the controller's keyboard what the signals are.

Doesn't look like there much logic on the power cards, it may be the there are 4 individual
winding drive signals on the cable.

A good picture on the top of the card so you can read the part numbers might help figure
out whats going on.
 

ok, i can try to remove logic board to see the top.

I bought the strongest driver of 7A, I will try as soon as I find some time to connect the existing motor in a bipolar connection with higher voltage and lower amperage, so we will see, if one works I will buy two more drivers and I think the problem would be solved, the controller in that case 7i96s for example.

feedback is a linear measuring scale for all axis, in case those remain, I can additionally take a card that would read them as an encoder