Enco rf 30 y axis problem

[fieldmouse]

Hi folks.
First time posting here. I bought this older 1984 enco machine a few months ago. I think it's a rf 30 or 31. The PO told me when I bought it that he was having problems with the y axis feed. I assumed he was an idiot and I'd be able to fix it easily enough. Turns out I was only half right. I took the machine apart to clean ,rebuild and transport right away. Although I did take pictures I must of missed this important detail.
The nut on the y axis screw doesn't seem be like any other example I've seen searching thru the web. In the pictures you can see how it's been drilled and tapped from 2 sides. One side having smaller holes which could be set screw holes but why? When I install the screw and it's approx position the nut is obviously far from the bottom of the table. In fact the bolts that fit there would project into the screw if fully tightened.
What am I missing? A 1/2 shim? Is it a hack job from another owner( my guy was honest I'm sure). Not the original nut?
Any help would be appreciated
Mouse

 

[C-Bag]

Sure looks like a botched attempt at a new Y nut. The factory nuts don’t look anything like that. Both X & Y nuts on my RF30 are brass. That one looks like steel. Hard to tell but it looks to me like the different attempts at mounting holes have a different height and neither is the right relative height. Mine has no spacers and both of mine have adjustment for taking out play.

 

[fieldmouse]

Yeah that's was my sinking assement as well.
The thing that surprises me is if some one had the skills to thread a left hand acme in that chunk of metal and then botch the mounting of it so badly.
What's the prevailing wisdom for replacing one of these nuts? I looked online and only found peoples fairly skilled dyi approaches.
Mouse

 

[markba633csi]

Looks like you just need to come up with a spacer and you could use that one for a while. It really should be bronze eventually

 

[pontiac428]

I think the backlash compensating plate that would mate to the face of the y nut is missing. That could still be a Rong Fu part. Models 10 years later were cast bronze and saw cut with a single pinch bolt for backlash. With access to a lathe you could complete that one or make a replacement. Maybe try Enco, HF, Jet, Grizzly, or Rong Fu for a replacement.

 

[fieldmouse]

I'm thinking about the spacer. I'm eons away from being able to turn a new nut. I like the sound of a " backlash compensating plate" but as of yet I haven't seen any versions of my mill with those 2 side by side mounting holes.
If I make a spacer I'm thinking I'd make it undersized and shim it until the lead screw runs smoothly.
Incidently I just went into the shop to see just how well this nut fits..ehhh. pretty sloppy.
Really appreciate the replies.
Mouse

 

[C-Bag]

This kind of project is hard because you don’t have a good nut to copy. And like so many repairs I’ve had to do you need the use of the very machine to make the new part.

I got a new Y nut from Grizzly several years ago. I believe it was cast iron not brass and according to someone I view as an expert here a good cast iron nut will wear better than a brass one. It was pretty reasonable where the x was outrageous to me but the wear on my Y has not reached the point where I need to replace it. My X is at the end of its adjustment but it is ok. Personally I want to try a nut made of Delrin and if I ever get around to it that’s what I’ll make my new X nut out of.