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Logan 10" rebuilding

Your saddle oil grooves look fantastic! I am envious, I want to have those on my Logan lathe saddle as well.

I was planning to make a single groove on each of the three surfaces. Each groove would have the form of Z, because that is easiest to do on the mill, and because it has no sections that are parallel to the direction of travel. Why did you decide on a sinusoidal shape? And why six grooves instead of three? Was it to avoid the central areas that you scraped high, because you did not want the oil to drain from there?
 
Your saddle oil grooves look fantastic! I am envious, I want to have those on my Logan lathe saddle as well.

I was planning to make a single groove on each of the three surfaces. Each groove would have the form of Z, because that is easiest to do on the mill, and because it has no sections that are parallel to the direction of travel. Why did you decide on a sinusoidal shape? And why six grooves instead of three? Was it to avoid the central areas that you scraped high, because you did not want the oil to drain from there?
I am not sure I have any answers for you. I didn't spend much time planning or researching optimal shape I just drew them out how I thought they should look.

I vaguely remember my monarch tailstock base grooves having a similar freehand curve shape.

Maybe cutting full length grooves would be better but it seemed like that would be overkill. In my thinking the middle will only ever loose oil to the outside so it doesn't really need to be oiled there, and having it grooved would only promote it to loose its oil film.

Any pros want to weigh in?
 
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I found a picture of the monarch tailstock oil grooves. Lots of wear on the old girl - a lot more beat up than the logan. Good iron is hard to find where I am!

20221106_074227.jpg
 
An addendum for those who want an alternate to turning a lead screw.
McMaster-Carr has a round 3/8-24 tpi coupler and 3/8-24 tpi threaded rod. Simply screw it all together and Lock-tite is your friend. A hex coupler can be drilled and used as the dial carrier. Most then cover the whole extended screw and lock it in place with set screws. Then place a larger Bridgeport style direct read 200 division on a carrier as shown earlier with a dial lock. Hard to find, but Hardinge dials can be fitted this way. Hardinge fits the index ring to the outside of the screw cover, bearing housing on the Hardinge, with a single set screw. No need to use turned down 3"+ stock for the whole extension.

There are 3/8" shaft wave washers available with 6 - 32 pound loads at very low compression. I found a manufacturer of anti-backlash nuts who recommends 35 pounds. An additional possibility is simply a cavity with the depth required to hold the washer, or thrust bearing, and the compressed spring. I now believe the Oilite thrust washer is preferable so no oil port is required. They spec at over 1,000 punds of axial load.
 








 
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