Lead screw binding when thread gear nut tightened

[Mike C5]

I did some searching on the forum but didn't find an answer to this. I finally bought some lathe change gears for my 1933 vintage 9" Junior and tried them out. I noticed that when installing the lead screw gear and tightening the nut, there was binding between the gear and lead screw bracket. It appears that the shoulder on the lead screw doesn't stick out of the bracket enough to prevent this. I see the lead screw has a pinned collar on the other side of the lead screw bracket which keeps the lead screw from moving left. So it would appear my only option is to machine a washer that would fit over the lead screw end to extend the shoulder of the lead screw. Or am I missing something? Did the machine originally come with a washer to prevent this binding?

 

[SLK001]

So it would appear my only option is to machine a washer that would fit over the lead screw end to extend the shoulder of the lead screw. Or am I missing something? Did the machine originally come with a washer to prevent this binding?

Different gear, a washer, or a myriad of other conditions could have originally been present. From your photos, it looks like the driving gear is slightly outside the driven gear plane, so a washer could do the trick. It the photo is not showing that, then just machine yourself a washer so that the leadscrew doesn't bind any more.

 

[Mike C5]

I looked at it again after realizing that with the large, fine feed gear on there (that came with the lathe), I had no such problem. I tried cleaning up the thread gear and now it works.. Maybe a little surface rust was doing it... The other thread gears seemed to work ok too. Strange...