I saw some great threads about going to 2x4 table and I know that the new Pro will do 4 x ~3 but I don’t want to buy another table since I already have one and love it. We bought the XL kit and were thinking that instead of even installing it we could just go full ham and build a 4x4 table.
The biggest challenge I would think would be to either run dual motors or linear sliders (thank you @BrooklynBravest for your incredible thread on your 2x4 expansion) for the Y axis but everything seems pretty straight forward otherwise.
Wish I had the floor-space for a 4x4, and yes I would use dual motors for such a rig. Another option could be a larger motor and a toothed belt linking the two leadscrews. But dual motors is surely simpler and the more elegant solution IMHO.
I have spent an inordinate amount of time this morning reading about adding a z-axis (I love this forum) and it’s pretty high on the list. I’ve ruined quite a few pieces because the torch caught on rapid and shifted the work piece. I could live with the additional time spent on the machine if it meant I didn’t have to scrap something that was running for a while.
I’m not so sure that two motors is a better solution. I’ve had a few variations of CNC routers, one with two Y Axis motors and one with a toothed belt and it is a lot easier setting up Y orthogonal to X and, once it’s set up, it doesn’t get out of sync (unless couplers slip) with the toothed belt approach.
Well, you may be right in this case. The toothed belt approach would require a bridge between the two Y rails and that would block the path to the surface of the table making it harder to get material on and off. Me being a weakling dude has to consider that aspect
I’m favoring the 2 motor solution as well just so I don’t get a lot of deflection and levering on an arm that long, just need to make sure the impedance is as close to identical on the wires to the motors as humanly possible (making an assumption here that this is some kind of i2c kind of communication and I wouldn’t want any drift on the clock wire). I wouldn’t mind looking into the possibility of going to a ball screw setup versus the lead screws with plastic guides but I think that would change my math a little bit but doable.
Whatever we end up doing I’ll document the crap out of it and it’d make great content for my youtube channel.
The motor wiring is purely to drive current into the stepper windings. Y axis is typically 4Amps and, given it’s powered from 36 volt supply, the variation in inductance (impedance) has a negligible effect.
If I’m not mistaken, the CF Delrin lead nut is constructed to withstand crashing into the hard stops without breaking anything. I think a Ball Nut wouldn’t be so tolerant.
