17" Clausing Colchester half nut adjustment

It's just what the title says. Replaced the half nuts and I'm wondering where to start the adjustment from. There's a set screw in the saddle that acts as a stop for the top half nut. The lower nut has a 1/4 - 20 socket head cap screw and a 1/4 - 20 set screw. The cap screw screws into a block that slides within the lower half nut. The block contains the pin that rides in the cam. The set screw threads into the half nut and acts as an adjustment for the block within the half nut. After assembled the centerline of the nut halves is to high, lower half is engaged in the lead screw in the released position. The original nuts were worn on the threads and the engagement lever would not stop when pushed down. Starting position was about 11 o'clock and when engaged the handle could be pushed to the 6 o'clock position and beyond. Is there some sort "hard stop"? I've heard that the only stop is the nut bottoming out on the root of the lead screw thread. I'll take another shot at this tomorrow and let you know how I made out. If anyone has any experience with these I'm all ears.

Post some photo's of what you have. It's like looking into a crystal ball guessing at what you have and how to help you. I think I know what to tell you, but want to see the design first.

Okay I figured it out. Sometimes there's to many trees in the way to see the forest as my Dad used to say. First setting is the set screw that acts as a hard stop for the top half nut. I used this to center the nut. Not really center. The upper nut when set is further away from the screw then the lower. The lead screw sags so you have to take that into account. You then use the set screw to back the lower half away from the screw till it doesn't drag when disengaged and fully engaged in the lead screw. it takes a little trying. When you get this set tighten the cap screw to lock things in place. Run the carriage back and forth the length of the bed and make sure the lower doesn't rub on the lead screw, adjust as necessary. When all was set I ran the spindle at a low speed on a coarse thread setting. I think it was 2 TPI. Engaged the half nuts and fed left to right and right to left. I did this to run the nuts in. I wasn't expecting a tremendous amount of wear just wanted to make sure all was right. One thing I did notice was the chasing dial is not indexed inline with the numbers and the fixed pointer. My thought was who ever made these started the thread at a different position then the original. The gear on the bottom of the chasing dial is pinned. Not like I can loosen a set screw and line things up as needed. When I had the apron apart i found a broken spring for the interlock (prevents the feed being engaged while the half nuts are engaged). The bottom of the apron was full old coolant and crud. I think the spring didn't break it rusted out and snapped. I haven't mastered posting pictures, okay I don't know how. I'm technology challenged! That's why I didn't post them. Hope this information helps someone else.

Thats a problem with all later Colchesters....the apron fills up with fine swarf,coolant,and goo,and everything rusts and stuffs up..............the apron is difficult to take apart,no one bothers..Another point is getting fine ,hard swarf embedded in the half nuts.Sometimes big pieces too.

Noticed that too. Also noticed there doesn't appear to be a way to oil the half nut slides. Not slamming these machines but I've done repairs on American and Cincinnati machine tools. They appear to be a better mechanically made machine. Tried to adjust the clutches, couldn't get the slide collars to move far enough back to make the adjustment. But that's just my opinion and I've been known to be wrong!