Hello,

After a lot of reading on the cnczone forums, I bought an X2 clone from Harborfreight and have outfitted it with a ballscrew CNC kit from CNC Fusion. I decided against buying the pre-loaded ballnuts.

Initially, I just used the CNC'd machine as a glorified drill press for drilling holes in PC boards. Now I am trying to actually do some CNC milling.

In Mach3, I have tried the "Cut Circle" wizard. Using a 0.25" diameter end mill, I tried cutting a 1" diameter circle... and ended up with an oval that is 0.975" wide and 0.940" tall.

From what I have read, my problem is almost definitely backlash. I set up my dial indicator on the X axis and found backlash of less than 0.001". I then tried pushing the X axis back and forth. There's the problem! It can move side to side by about 0.012". However, under no load, this slop does not appear to cause any backlash.

Does anyone know what my problem is? Is it backlash? And how do I fix it? Do I need to go to pre-loaded ballnuts?

Thanks,
Kyle