BP spindle reassembly

[lakeside53]

My first post on this site, so go easy.. Yep, I used search and read all I could find... No, I'm not a pro.. just an avid hobbyist with a lot to learn that wished he'd started machining a lot earlier in life...

6 months ago I couldn't spell Bridgeport, now I own two. My Emco V10P mill just wasn't what I needed, and being frugal (another word for stupid), bought a couple of wrecks (1967 step pulley and a 1977 2hp series 1) believing I could build one from two.. Well... as you all well know, it would have been a lot cheaper to buy one decent mill, but that's all water under the bridge. I've been bitten by the bug, have both stripped down, my step pulley head completely apart and close to reassembly. I now intend to rebuild both machines.


Today's question.. the spindle assembly (I never ran it under power). It appears that the top bearing (6206 C2) either got locked up or the lock washer/nut was incorrectly installed. The top spacer was "hand pressure loose" and spun against the top bearing. Net result is that the spacer has a groove worn in the top and in the process loosened the entire assembly. I understand that the lower two 7207 bearings get their preload by the precision spacers between them and the clamp pressure from the top spacer.

My question: does the top spacer need to be precision ground like the lower bearing inner and outer spacers, OR can it just be cleaned up "accurately" in a lathe?


The 6206 will get replaced. The 7207's seem o.k.. They might get replaced later, but I want to evaluate them under power.