Y axis backlash

I'm looking for information about how to get at the Y-axis ball nut assembly. I'm guessing that I either have a loose bracket or something is wrong in the anti-backlash adjustment as I'm getting a consistent 0.007" backlash in X. I've tightened the bearing cap to no avail. My mill sits in a chip tray with the bottom of the table right above the tray so it's not practical to get at the bottom of the mill. I'll pull the whole thing out of the tray if I need though.

I guess the question is whether to go at this from the top down or bottom up. Your thoughts?

Ken

The Y axis nut mount on these mills is bad for working loose. They only have one bolt and very little surface area to give stability. You will have to go from the top down so no need to remove it from the tray. Just remove the table and go from there. When you unbolt the one bolt clean everything real good (carb cleaner spray or paint cleaner) and use blue Loctite on the bolt when you install it.

Many people have remade there Y axis mount to include a extra bolt but this will require doing some mill work on the bottom of the saddle where the nut mount fits. Well worth the effort if you can get to another machine to do the cutting. If not using the Loctite will help a lot.


Jess

The y ball screw mount on my mill (circa 2010) is held by two button head bolts. And as I recall you would need to get to it from below as it is fastened to the underside of the mills base.

I believe Saabman is right on this ( sorry), I just looked at the CNC Cookbook web site ( Bob's IH build) and his comes form the bottom and had two bolts with the IH change over. All though it does look like the factory leadscrew nut mount may have been a single bolt like mine.


I just happened to have my table end off tonight and got to looking at mine and even its bolt come from the bottom. But I can get to it through the slot which is what I did to tighten mine. Still this is not a ballscrew and I had to back the screw out of the nut to get to the bolt. If the IH double bolt setup is not right under the screw it may be possible to get it this way.


Taking a mirror and moving the Y axis out then through the slot one could see what was happening to get a better idea what needed fixed, and see if it could be reached. . Also the end bearing mount should be checked to make sure bearing preload had not got loose ( the screw will move in and out if so).


Jess