Y ball screw issue

[Threadkiller]

Thank you sdelivery. I actually figured out what was going on. I took the dial off the collar and re assembled it without it and was able to see what the problem was. The previous owner only had one shim between the dial and the collar, nowhere near enough. I thought my ways had so much wear and thats why it was so hard to turn so I never looked into or noticed anything with the collar. This past weekend I noticed that the backlash was getting worse so I started watching the dial and thats when I noticed it was making contact. So I guess from the contact the 3/4" nut on the handle backed itself off and there was so much backlash and it was feeding itself in and out which made me catch was the actual problem was thankfully. Thank you for all the help and suggestions. I called H&W and they suggested putting everything back together without the dial which made the problem really apparent and helped rule out the bearings being the issue. They are super nice there.

 

[dabear3428]

If you need or want you can just take the entire screw assembly off with just four screws and take it to the bench....you can see the dark section behind holds the bearings....View attachment 457191View attachment 457192

lol not on a ball screw, unless you want to chase balls all over and repack the ball nuts

 

[B2]

One other less likely problem is with the gib. If it is not locked in place well, it will slide in and out as you change directions. This means it will be tighter in one direction of motion than in the other direction. Hence, harder to turn. If it is not locked down at all it will get so tight in the one direction that the slide may bind up completely, but only in one direction! This is then the ultimate backlash! Likewise, even less likely is that the ways are not parallel over the travel distance. When this way error is bad it means you can never get the gib set correctly as the friction of movement is low when the ways are separated, but the gib is tighter as the ways closer together (or the reverse). Hence, the backlash will be different at different positions along the way travel.

 

[B2]

lol not on a ball screw, unless you want to chase balls all over and repack the ball nuts

In my machine the ball nut will not even slide off the lead screw shaft unless the balls have been removed! This is because the lead screw thread does not go to the end of the shaft. The OD of the non-threaded portion of the shaft is the same size, or slightly larger, than the OD of the threaded portion of the lead screw.