Need some help converting a Triac mill to Mach 3.

Hello

I'm part way through the conversion of a Triac milling machine to Mach 3. I did a lot of research before starting the conversion and due to a pretty tight budget I've opted for trying to tie into the existing hardware as much as possible. So far by following a superb forum thread on the Denford site (Help with Triac VMC converting to Mach - Denford Software & Machines) I've added the Step and Dir lines for the X,Y and Z axis to the existing driver boards, and all axis' currently step once if connected to ground. I've built a simple transistor amplifier circuit to switch these 24v lines from a 5v supply that I was hoping to get from the BOB.

I have been advised that the BOB doesn't output 5V for signals, rather it connects to ground when 'on'. I have added 2 diagrams below, the first the my current circuit that does step when I connect the 2K resistor directly to a 5V supply on the BOB, but not when connected to the step or dir pins (2 & 3) on the BOB I have. The second builds of the circuit diagram on P4 of a stepper motor driver instruction booklet (https://www.omc-stepperonline.com/download/DM320T.pdf) I don't know if this would work at all. I'm right at the limit of my electronics know how and any advice would be much appreciated.

Thanks in advance, Dan.

Hoi Dan,
Your first diagram looks fine to me. But what BOB are you using. do you supply 5 V to the BOB. Most of them have opto couplers on them and the secondary site needs power.
For test connect a LED with 2K resistor to the BOB DIR output, drive the axis in one direction. if the LED stay's off, drive the same axis in the other direction. If the LED still doesn't get on, you are missing power on the output side of the BOB.