At 75 I'm terrible about the right terms for different parts of the OX so I apologize if it doesn't sound right but I'll try and explain the best I can. I've already built one Ox that nearly killed me and my wife forbade me to build any more, (The divorce is ongoing) but after surviving Covid for the last 10 months I'm sure It's time to have some fun and build another Ox. (If Covid didn't kill me maybe the Ox will, much better way to go I think). I'd like to know if it's possible to change from belt drive to screw on the Ox as I was sure that was the best way to go when I built the first one. The belt drive seemed flimsy compared to the toughness of a screw drive. Also, I have 3 Nema 34s sitting on the bench itching to be used and I'd like to put them to good use. I'd be grateful if anyone has done something like this to let me know. Thanks a lot.
Dig through that area of the Builds Section of the forum. There are a number of good examples. For the most part the screws are set outboard of the gantry plates. Way too powerful for anything Ox. One wrong move and the system will be reduced to a twisted ball of metal. There's no reason the NEMA 23s you currently have won't work with the new configuration. Screws have far more mechanical advantage than the pulley/belt system so their effective power will be 5 to 7 times what it was in the old configuration.