Is this any good

Your current bottom nut is well worn but still most likely reasonably functional. But probably have seriously excessive play in the thread between nut and screw.

As Ady1 says babbitt metal makes a perfectly adequate cast leadscrew nut. I believe the half nuts on my P&W 12 x 30 model B are cast babbitt. P&W had a well deserved reputation for making machines of the highest quality so clearly an eminently satisfactory way of going about things.

However the strength properties of epoxy steel, epoxy ceramic et al industrial repair materials are of similar order to babbitt. Perhaps 1/2 to 3/4 as strong depending on parameter and what specific materials you are comparing. Objectively more than strong enough in absolute terms.

Hence, as I suggested in my earlier post, applying some to the nut and pressing the leadscrew in to form an accurately replicated thread should work well to give a new thread of minimal clearance. Fundamentally an easier way of going about things as you can work cold and there is no need to provide dams to prevent molten babbitt escaping. Now we know you only have to deal with a single half nut the jib becomes much simpler than I suggested earlier.

Here is a link to a basic overview covering the Devcon range of such products :- **LINK**

https://www.aimsindustrial.com.au/assets/files/Devcon-Product-Guide-Catalogue.pdf

Devcon are a respected supplier of such materials to industrial users with a pretty comprehensive range. That guide gives a good idea as to what sort of "trowel it on" repair materials can be found at the more sophistcated end of the market once you start looking beyond JB Weld and similar consumer varieties.

Clive

Edited By Clive Foster on 27/09/2022 20:07:28

Just give it a go. Nothing to lose . My approach to these very old lathes is to go gently and only change what is not working. If you want a precision to the last thou your looking at the wrong lathe. Get it just so and you have a decent lathe. Enjoy it !