First my tool post compound slide was too loose. Simple fix was tightening down gib screws until it wouldn’t move. That helped the lathe finish. Until I had time to scrape and get the proper fit.
I also had a loose lathe spindle giving be a bad finish. Check that and tighten if necessary.
Next problem is the ways and beds were not fitting tight enough. I had scrapped them until I had good contact.
My ball screws were too loose. I have tightened my Y axis with larger balls. This was a simple thing. I still need to order a few more sizes of balls to tighten it up some more.
If the x bed is not getting at least 75% contact you will have excessive play that is hard to control.
I actually got me a torque screw driver so I could set the gib screws to an even pressure. Thought it would help. It did but not worth the cost for the gain I got out of it.
I took out the mill spindle and repacked the bearing and tighten up the spindle play I had.
I had cut my first full cnc part a couple of weeks ago. It came out great except I could see tool chatter in the finish. I am hoping the finish will now be better since the spindle work.
I am still tweaking. So it’s not perfect…YET.