what config do i use for 4 pins to 4 phases?

insanegenius wrote:

I have 3 stepper motor's and each has 4 wires. They need a pulse per wire for each phase. So, from the parallel port I would like for the X axis a pulse being sent from pin 2 then pin 3, then pin 4, then pin 5 for forward stepping. (And in reverse order for reverse) The same thing would work for the y and z axis. 4 pulses through 4 pins per step motor.
What configuration do I start with or use?
thanks

Are you expecting to power the motors directly from the parallel port, or is there extra hardware that you haven't mentioned?

If the motors only have 4 wires then you have to use a bipolar drive, there is no choice, and those almost all use step and direction pulses from the parport (or other interface)

insanegenius wrote:

From the spec sheets it looks like these are unipolar motors. I am just taking the output of the parallel port pins and amplifying the signal to 12v dc. Is there a setting in linuxcnc for this? Or am I doing something major wrong here?

If you want 4 unipolar drive signals, then that is easy enough, and is step type 5: www.linuxcnc.org/docs/2.4/html/hal_rtcom...b:Stepgen-Step-Types

However, typical stepper drives run the motors at a much higher than rated voltage, and control the current with a chopper. This allows the motors to run a lot faster.

I think you will find that 12V DC rather overheats your motors. They tend to be rated at 5V or so DC.

Depending on the current required it is possible to run a unipolar motor with just a parallel port and a ULN2003 chip:

arduino.cc/en/Reference/StepperUnipolarCircuit

insanegenius wrote:

yeah that is exactly what I am using the unl2003a. would you be able to give me some step by step instructions of how to get this to work? I have 3 uln2003a chips and 3 printer stepper motors. The steppers show 12-24v. I am studying the 2 pin setup in the link you sent. But if I stick with the 4 pin setup do i just use a generic config then change the values to 5?.

Further down the page there is a 4-pin diagram, that is the one you want.

Start with a sample stepper configuration from the config picker, then change the step-type to 5 in the HAL file.

You will need to change the stepgen pin names and parallel port pins in the HAL file to suit the new stepgen type (you will have phase-A etc not step and dir).
You will need to pay attention to which parallel port pins are available as outputs.

www.linuxcnc.org/docs/html/man/man9/stepgen.9.html
www.linuxcnc.org/docs/html/hal/parallel_port.html