Warning, rambling preamble ahead. Feel free to skip to UPGRADES to learn what I did that helped.
Not really sure where to post, it's only around half a ton but certainly no Bridgeport. It's from WWII but the guys over in antiques all have Lunkenheimer oilers and babbitt bearings, so here I am.
The first vertical mill worth the name I ever owned was an old Index Mdl 40. Some while ago I got nostalgic and bought myself one to replace the one I'd sold, thinking I'd want a mill when I retired and might be short on space so the Index would be a good mini-mill. Thing is, the one I'd bought (sight-unseen) was really very rough cosmetically, and not ideal mechanically. So I got it off the truck and immediately completely disassembled it. That was over five years ago. A few days back I decided it was time to quit fooling around and just put it back together, just barely as some parts had drifted to difficult to locate areas, so now I have a mill that is rather uneven in it's appearance but usable. I had planned a lot of labour-intensive tasks, Cleaning, prepping, and painting the base and knee took a lot of my time but only a couple quick things got done mechanically. So I'll share those along with the admonition that it's unwise to start a restoration of a machine if one already has a lifetime worth of projects underway in the shop.
I also did miss the rapid-quill option (one reason I sold my first Mdl 40) so I bought a nice clean Bridgeport M-head I could put on in case that came up for me. Of course, the whole short-on-space thing hasn't really come up for me and since I bought a 4200' building it seems unlikely to. Or at least I might be short on space but not short enough that the difference between a Mdl 40 and full-size mill is going to matter. :-)
UPGRADES:
The ACME screw for Y was pretty tired but really most of the wear was in the nut. Simply slitting the nut on the bandsaw about 3/4 of the way through 5/16" from one end, then drilling, tapping, and spot-facing for a cap screw on either side, gave me a nut I could adjust for wear and reduced quite significantly the backlash in travel.
Of course it's important to tighten it only as much as sensible on the least used part of the screw. In my case that was the very back of the travel. I also found that putting the part with the flexure in it toward the front of the machine made it easier to adjust and helped me get a better fit.
Get some roller thrust bearings and thrust bearing washers, the ones for X and Y are 5/8"ID (4 total). They are stupidly cheap these days and replacing the worn bronze or cast steel washers with then made table movement vastly smoother and easier. I was also able to run a little more pre-load on the gibs and lead-nut as a result. It looks like there is also room for one on the screw that presses down the quill, 1/2" shaft there, but I was rushed so that one didn't go in.
DRO. Even with improved handwheels and leadscrew nuts, for that matter even if I got new acme screws, there would still be some backlash. Handwheel measurements are time-consuming as well and my eyesight isn't helping that any.
So, for much less than the cost of new acme screws I picked up the bits to put glass scales on all three axis.
For machines with tight-quarters I like magnetic scales, but this little machine actually has plenty of space in reasonable places to put the glass scales. For $300 for three axis plus readout head I couldn't cost justify a nicer setup.
Not really sure where to post, it's only around half a ton but certainly no Bridgeport. It's from WWII but the guys over in antiques all have Lunkenheimer oilers and babbitt bearings, so here I am.
The first vertical mill worth the name I ever owned was an old Index Mdl 40. Some while ago I got nostalgic and bought myself one to replace the one I'd sold, thinking I'd want a mill when I retired and might be short on space so the Index would be a good mini-mill. Thing is, the one I'd bought (sight-unseen) was really very rough cosmetically, and not ideal mechanically. So I got it off the truck and immediately completely disassembled it. That was over five years ago. A few days back I decided it was time to quit fooling around and just put it back together, just barely as some parts had drifted to difficult to locate areas, so now I have a mill that is rather uneven in it's appearance but usable. I had planned a lot of labour-intensive tasks, Cleaning, prepping, and painting the base and knee took a lot of my time but only a couple quick things got done mechanically. So I'll share those along with the admonition that it's unwise to start a restoration of a machine if one already has a lifetime worth of projects underway in the shop.
I also did miss the rapid-quill option (one reason I sold my first Mdl 40) so I bought a nice clean Bridgeport M-head I could put on in case that came up for me. Of course, the whole short-on-space thing hasn't really come up for me and since I bought a 4200' building it seems unlikely to. Or at least I might be short on space but not short enough that the difference between a Mdl 40 and full-size mill is going to matter. :-)
UPGRADES:
The ACME screw for Y was pretty tired but really most of the wear was in the nut. Simply slitting the nut on the bandsaw about 3/4 of the way through 5/16" from one end, then drilling, tapping, and spot-facing for a cap screw on either side, gave me a nut I could adjust for wear and reduced quite significantly the backlash in travel.
Of course it's important to tighten it only as much as sensible on the least used part of the screw. In my case that was the very back of the travel. I also found that putting the part with the flexure in it toward the front of the machine made it easier to adjust and helped me get a better fit.
Get some roller thrust bearings and thrust bearing washers, the ones for X and Y are 5/8"ID (4 total). They are stupidly cheap these days and replacing the worn bronze or cast steel washers with then made table movement vastly smoother and easier. I was also able to run a little more pre-load on the gibs and lead-nut as a result. It looks like there is also room for one on the screw that presses down the quill, 1/2" shaft there, but I was rushed so that one didn't go in.
DRO. Even with improved handwheels and leadscrew nuts, for that matter even if I got new acme screws, there would still be some backlash. Handwheel measurements are time-consuming as well and my eyesight isn't helping that any.
So, for much less than the cost of new acme screws I picked up the bits to put glass scales on all three axis.
For machines with tight-quarters I like magnetic scales, but this little machine actually has plenty of space in reasonable places to put the glass scales. For $300 for three axis plus readout head I couldn't cost justify a nicer setup.