Hi All. I am at the rebuilding part of putting a Rockwell 21-100 milling machine back into working condition. I just picked this machine up about a month ago, it seems like it has had a good life, and has not been abused too badly. It is fully disassembled, and came apart with no real difficulty. I think it had the original bearings in it. the paint is mostly off of this machine, now, and paint prep underway. The ways look to be serviceable, but I have not checked to see how precise they are, yet.
The focus right now is on the spindle / quill, and drive pulley. I have been scouring the net for information on spindle bearings, preload, and such, and think I have a decent grasp of the bearings. I have a matched duplex set of lower spindle bearings here, with a light built in preload, and there is a similar set of pulley bearings on the way. The journals for the bearings are in good shape. The residual caked up grease in the quill and adjacent to the races looked like New Year's glitter, the bearings were shot. All the bearings in the machine were shot. Everything cleaned up well, and I have been studying all of this before re-assembly. Some of the best bearing information I have found, has been on forums talking about Bridgeport spindle bearings.
I notice that the spindle spline fit into the drive pulley hub splines is not as close as I think it might should be. There is rotational wear in the splines, and radial wear, as well. It looks like it would run as is, maybe it is enough wear to begin causing some noise? It also looks like this fit is the 'weakest link' in the accuracy of the head, as the spindle bearings / pulley bearings are handled, and the wear in the quill / head does not seem too bad.
How much wear is acceptable in the spindle / pulley hub splines? How should these pieces fit, ideally.
At what point is it worth fabricating a new splined pulley hub that is matched to the worn spindle splines? ( the wear in this fit seems to be fairly even between the two pieces, maybe a little more in the hub than in the spindle)
I would like to bring this machine back to life as much as reasonably possible. If the quill / head is revived to a good state of being, I see some way maintenance, measuring, and scraping in this machine's future.
This machine looks like lubrication was not thought out all the way, so I am planning some minor changes in that department.
The focus right now is on the spindle / quill, and drive pulley. I have been scouring the net for information on spindle bearings, preload, and such, and think I have a decent grasp of the bearings. I have a matched duplex set of lower spindle bearings here, with a light built in preload, and there is a similar set of pulley bearings on the way. The journals for the bearings are in good shape. The residual caked up grease in the quill and adjacent to the races looked like New Year's glitter, the bearings were shot. All the bearings in the machine were shot. Everything cleaned up well, and I have been studying all of this before re-assembly. Some of the best bearing information I have found, has been on forums talking about Bridgeport spindle bearings.
I notice that the spindle spline fit into the drive pulley hub splines is not as close as I think it might should be. There is rotational wear in the splines, and radial wear, as well. It looks like it would run as is, maybe it is enough wear to begin causing some noise? It also looks like this fit is the 'weakest link' in the accuracy of the head, as the spindle bearings / pulley bearings are handled, and the wear in the quill / head does not seem too bad.
How much wear is acceptable in the spindle / pulley hub splines? How should these pieces fit, ideally.
At what point is it worth fabricating a new splined pulley hub that is matched to the worn spindle splines? ( the wear in this fit seems to be fairly even between the two pieces, maybe a little more in the hub than in the spindle)
I would like to bring this machine back to life as much as reasonably possible. If the quill / head is revived to a good state of being, I see some way maintenance, measuring, and scraping in this machine's future.
This machine looks like lubrication was not thought out all the way, so I am planning some minor changes in that department.