So I’ll start off by showing I’m not a complete tech idiot.
I took a 1981 Bridgeport Series 1 CNC, replaced the screws with ball screws, gutted the electronics, rewired with new VFD, new Servos, new drives, acorn Cnc controller, works flawlessly. Can hold accurate .0008-.001 all day long now for over a year with weekly use.
This XR Pro… since new…
It’s within 1/64 of being square and I spent two hours leveling the thing. Following the instructions for assembly to a T.
the plastic cover over the torch was not trimmed large enough and the torch (hypotherm machine torch) constantly stalls then jerks when it’s cutting. I trimmed the plastic bigger but it’s still wonky.
anything over 200ipm it gets out of square and completely screws everything up, which was a huge problem until I figured out in settings you can slow the machines travel speed between the cuts…. But it’s really quite annoying.
I double checked, triple, then quadruple checked that the rails are 100% inline at every point on the table, and when homing the machine it is perfectly square with the rails so it’s starting off straight.
I then bought a $100 torque wrench that went down to 10 inch lbs so I could be 100% certain that the ball screws were in the exact same tension. I tried at 20 in-lb, 30, 40, 50, 60, 70, all the way to 180. Nothing helped it move uniform.
I loosened the jam nuts on ball nuts…. Nothing, tightened them…. Nothing, tried them at a happy medium, nothing. Removed the felt pads, re-oiled them. Nope.
I covered entire ball screw in assembly lube. Nothing. Greased the entire rail. Nothing.
One thing I think might be the cause, one of the gantry upright braces seems to be bent (or wasn’t made perfectly straight) from the factory. When the machine is homed, one of the rollers does not touch the rail. And nothing I can do will make it touch.
I will begin a cut with THC on, it will cut the first hole at normal height. Move to the second hole, start the cut 1.5 inches from surface and not cut anything. The ground is directly connected to the workpiece. No idea what to do here. 90% of the time I push retry cut and regenerate code it either starts back in the wrong place or completely skips one of the holes.
it constantly fails to start because it detected some voltage prior to moving or something. I don’t recall the exact error but I’ll try it tomorrow and update with exactly what it says 1 out of every 5 times I start to cut with it.
the mechanism that is used to hold the torch at 90 degrees from the workpiece is poorly designed and moves constantly. I plan to drill holes and put two u-bolts on it.
I’m ready to sell it and buy a more expensive more reliable unit. I use it to cut custom brackets, ears for pins etc… 5-6 times a day every day of the week. And it’s gotten to the point where I just use the handheld plasma, freehand and grind rather then screwing with this for an hour to get it to cut something.