Thanks A ton for finding that I wasn’t having much luck finding anything other than expansion boards but they were around $20 and only added 1 stepper which was way to expensive for my taste. I was able to find this based off the one you found on aliexpress, it seems a bit cheaper and there are some better shipping options to the states. I am going to order a couple and see if I can slave one of these to my existing on board driver somehow, hopefully without too much customizing. Will try and let you all know how it went in a couple of weeks when all the parts show up.
Reply To: Stacking Stepper Drivers?