Hi all,

Been lurking here for a little while and ran into a problem that (hopefully) someone can help with.

I recently bought a Harbor Freight X2 Mini Mill and a CNC conversion kit from CNC Fusion. I believe it was kit #2, or whichever one converted all 3 axes.

I installed everything, it went pretty smoothly. Got the control board put together to run with Mach3. X and Y axis work like a charm, no binding whatsoever. Both move quickly and quietly. Then comes the Z axis...

Essentially, the Z axis will jog downwards PERFECTLY. It is smooth, quiet, zero binding issues. HOWEVER, when I jog the mill upwards on the Z axis, it binds horribly. The motor starts grinding, the head starts vibrating, it's a mess. It will sometimes move an inch or so freely before the process repeats.

I have disassembled and reassembled the Z axis 4 times. I have adjusted the gib each time. I have left the two 5mm fine feed screws out of the ballnut block so I could adjust the angle of the block (if you're familiar with the CNC Fusion kits). I've left the motor mount block screws loose and tried adjusting it from the top. I lubed everything as much as I could to ensure it wasn't a friction problem. No luck.

Not real sure where to go from here or if anyone might have other suggestions. I'm not sure if it is a problem with my mill or the kit itself. As I grow increasingly agitated each time I have to disassemble and start over, I thought someone with some additional experience might be able to guide me. I have sent an email to CNC Fusion, but it generally takes ages for them to respond.

Also, I can probably supply a video of the problem if it would be helpful.

Thanks in advance.