Hello all, I'm currently trying to get a newly acquired Walker Turner 20" drill press up and running again. The exterior of this press is in really great shape, unfortunately the spindle assembly was hiding some issues. I've started the process of replacing the spindle bearings, I have the quill removed and the spindle pressed out of the quill, destroying most of the bearings in the process.
I believe my drill press is of the earlier era before WT was bought by Delta, possibly 1944-1945? There is no split in the head casting like the later models I've seen. I think it is supposed to have a double row ball bearing for the lower spindle bearing, and a single row ball bearing for the upper. I removed a 6204zs bearing from the upper, so that seemed correct, but I pulled out two 7205 angular contact ball bearings from the lower spindle bearing location, not factory.
I don't really care about this having "factory" bearings, I would just like to fit it with something that works properly.
I've measured the bearing journals on the spindle and the bearing bores in the quill with various mics and bore gauges, measurements should be accurate to about .0002" or so.
Upper Spindle Bearing Journal .7887" at the top tapering evenly to .7892" at the bottom.
Lower Spindle Bearing Journal .9862" at the top tapering evenly to .9855" at the bottom.
Upper Bearing Quill Bore 1.8483" about .55" deep, round within a tenth or two.
Lower Bearing Quill Bore 2.0446"-2.046", diameter is tapered about .0005" bigger from bottom to top, bore is out of round by about .001" or so. Bored 1.45" deep.
Was looking at double row angular contact bearings to use as the lower bearing replacement. A 3205-2RS seems to be the closest fit.
3205-2RS ID - .9843"
OD - 2.0472"
Width .811"
This bearing would be about a .0015" press fit on to the spindle journal as well as about a .002" press fit into the quill bore. This seems pretty tight to me, it was definitely really tight coming apart. And from what I've been reading it seems that I would want an interference fit onto the spindle shaft, but more of a clearance fit into the quill bore, though I don't really understand what would keep the outer race from potentially spinning?
The Upper Bearing is similar,
6204-2RS ID - .7874"
OD - 1.8504"
width - .551"
About a .0015" press fit on to the spindle journal and about a .002" press into the quill bore.
I'm hoping someone more knowledgeable can advise on what the proper fits should be, currently I'm thinking something more like .0005" press fit on to the spindle journals and maybe .0001" or less press fit into the Quill bores?
I'm also having trouble finding any listings for a 3205-2RS bearing that specify what the ABEC rating or P class is. I see them listed as available in P5 classes in the Timken catalog, which I think would be about right for this application. Just a bit more towards the precision end and I think that would guarantee the ID and OD of the bearing within a few tenths of nominal, making my fitting process a bit easier.
I appreciate any and all help,
Thank you for your time
I believe my drill press is of the earlier era before WT was bought by Delta, possibly 1944-1945? There is no split in the head casting like the later models I've seen. I think it is supposed to have a double row ball bearing for the lower spindle bearing, and a single row ball bearing for the upper. I removed a 6204zs bearing from the upper, so that seemed correct, but I pulled out two 7205 angular contact ball bearings from the lower spindle bearing location, not factory.
I don't really care about this having "factory" bearings, I would just like to fit it with something that works properly.
I've measured the bearing journals on the spindle and the bearing bores in the quill with various mics and bore gauges, measurements should be accurate to about .0002" or so.
Upper Spindle Bearing Journal .7887" at the top tapering evenly to .7892" at the bottom.
Lower Spindle Bearing Journal .9862" at the top tapering evenly to .9855" at the bottom.
Upper Bearing Quill Bore 1.8483" about .55" deep, round within a tenth or two.
Lower Bearing Quill Bore 2.0446"-2.046", diameter is tapered about .0005" bigger from bottom to top, bore is out of round by about .001" or so. Bored 1.45" deep.
Was looking at double row angular contact bearings to use as the lower bearing replacement. A 3205-2RS seems to be the closest fit.
3205-2RS ID - .9843"
OD - 2.0472"
Width .811"
This bearing would be about a .0015" press fit on to the spindle journal as well as about a .002" press fit into the quill bore. This seems pretty tight to me, it was definitely really tight coming apart. And from what I've been reading it seems that I would want an interference fit onto the spindle shaft, but more of a clearance fit into the quill bore, though I don't really understand what would keep the outer race from potentially spinning?
The Upper Bearing is similar,
6204-2RS ID - .7874"
OD - 1.8504"
width - .551"
About a .0015" press fit on to the spindle journal and about a .002" press into the quill bore.
I'm hoping someone more knowledgeable can advise on what the proper fits should be, currently I'm thinking something more like .0005" press fit on to the spindle journals and maybe .0001" or less press fit into the Quill bores?
I'm also having trouble finding any listings for a 3205-2RS bearing that specify what the ABEC rating or P class is. I see them listed as available in P5 classes in the Timken catalog, which I think would be about right for this application. Just a bit more towards the precision end and I think that would guarantee the ID and OD of the bearing within a few tenths of nominal, making my fitting process a bit easier.
I appreciate any and all help,
Thank you for your time