Cylindrical square from a lathe tailstock.

[tonyfoale]

I had a spindle from the tail stock of a large lathe which I used as the basis for an accurate cylindrical square. Although the spindle was hardened it had some wear due to years of use on the lathe. This video shows how I lapped it true and checked it for squareness.

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https://www.youtube.com/playlist?lis...O1hdmUIYO28Def

I had an old aluminium bearing housing in the scrap box which had a bore of 50 mm and the tailstock cylinder was 54 mm so I made a lap by boring out the housing and then splitting it with a bandsaw. I added a couple of clamping screws for adjustment during lapping.

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I had machined the bore for a nice slip fit on the cylinder, but for the initial lapping I spread the diameter a little so that I could charge it with the lapping grit and some thin oil. I worked the lapping over the areas which were the largest. The cylinder varied in diameter by only 2 tenths of a thou. prior to lapping. Pretty good but I like perfection where possible.

Lapping.

After lapping I could detect no difference in diameter over its working length. So that left the squareness to the base to be checked.



I suggest watching the video for more details. Please like and share it and subscribe to my video channel if you have not already done so.