New to me Bridgeport mill

Keep in mind there are several levels of precision when it comes to acme threads. Those used in clamps don't even state a level of accuracy per inch. Those classified as "precision' only have an accuracy of .009" per inch. Those classified as "ultra precision" have an accuracy of .0006" per inch. I would think it would be extremely difficult for a beginner to hold .0006" per inch over a 32" length, especially when the rod would have to be repositioned multiple times to complete the job. Keep in mind you'll also have to turn the areas for the bearings, turn the length for the crank handle to pass over, cut the keyways, and turn the threads for the nuts on the ends.

A complete leadscrew from H&W is less than $300.00. Most lead screws are made from 4140 or stress proof bar. The bar would cost about $50.00 plus shipping and tax and have to be hardened after machining. Just some things to think about should you decide to take on the project.
 
projectnut said:
Keep in mind there are several levels of precision when it comes to acme threads. Those used in clamps don't even state a level of accuracy per inch. Those classified as "precision' only have an accuracy of .009" per inch. Those classified as "ultra precision" have an accuracy of .0006" per inch. I would think it would be extremely difficult for a beginner to hold .0006" per inch over a 32" length, especially when the rod would have to be repositioned multiple times to complete the job. Keep in mind you'll also have to turn the areas for the bearings, turn the length for the crank handle to pass over, cut the keyways, and turn the threads for the nuts on the ends.

A complete leadscrew from H&W is less than $300.00. Most lead screws are made from 4140 or stress proof bar. The bar would cost about $50.00 plus shipping and tax and have to be hardened after machining. Just some things to think about should you decide to take on the project.
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Ya, I don’t think I will be attempting that on 36 inch lathe. I could get paid more than the cost of the part working. If I had a lathe long enough to not have to reposition I would take it on. I didn’t know that about acme lead screws.
 
Here is the most worn way surface on the mill. How does it look to everyone? What would cause the wear to happen more on one side than the other? I’m going to be making way covers for everything. Right now I’m trying to figure out how I’m gonna get the chips out of every sliding surface without disassembling, but I’m gonna have to take it all apart. I don’t think I will be taking the knee off though. Look very heavy and not too dirty compared to all the other surfaces.
 

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