Excluding possible Failures / Troubleshooting LPT setup

Hello!

I don’t know exactly where to start, but I am out of ideas and need advice in this matter….

So, I got 3 HBS86H Stepper Driver hooked up directly to parport, all same parameters.
One Axis Moves both direction, but with stutter, one axis is smooth, but only goes in one direction (dir works, but it goes in one direction, no matter the pulldown occurs and is on the pin measurable) and one axis refuses to move entirely. It gets the same voltage input and also the dir pin pops when reversing, but nothing moves.

The stepper and driver work with grbl.

I spend the afternoon going over all the pins again, tested them, added USB +5v, then swapped to a 5+ step down to source the current from outside.

Among this setting, I tried to play around with it, but nothing seems to work. According to the handbook, those settings should be right I hope, I attached a picture of the timinig in the manual as well:



steptime: 2500 - 3000
stepspace: 2500 - 3000
direction hold: 6000 or more (possible up to 20'000)
direction setup 6000

also tried everything with 20'000 like in the instructions

I got activity on the drivers, as I measure it with a voltmeter (4.5-4. and when they should be activated, i see fluctuation according to dir changes and steps. So my guess is, the timing is not correct.

The Dir + and Step + are connected to the + of the source, the Dir – and Step – are connected to the LPT pin that correspond with the axis in stepconf.

The other outputs like mist, coolant and spindle works just fine.

Sound familiar to someone? Or is my config incorrect? What would be your guess?


Thank you
Roger

5000
5000
20000
20000
Set the base period in the ini file to 100000, save and restart LinuxCNC.
And i would change the wiring to common GND, meaning step- and dir- to gnd on parallel port, and step+/dir+ to pins 2/3 etc. This is just to be sure as i had one case where positive common required much longer timings.

Have you controlled the voltage of the pulses. If they are too low (you can read 3.5V in your sheet) you can get such results. Parports sometimes have only 3.3

i can't belief, it works, it finally works and the table moves as responsive as it should!

thank you very much for the help - pain is gone, now i can focus on building everything neatly. can't express in words how happy i am

Nice to see you happy again ?!?!