Yeh it's got plain bearings and 150rpm tops. I've got a couple ideas on working around that for when I need to work around those 2 particular pitfalls. I looked over the 41 spindle bearings documents you sent me, and guessing that will be one of the more involved aspects of rebuild/repair, unless I get lucky and they are tolerable.
Can you guesstimate what a tolerable level of running clearance would be on a machine of this style? I know clearance/fits for more modern ones with roller bearings and hard chrome spindles, but I doubt this would have such stringent requirements.
Going to bounce some of the frankenboringmill ideas off who's ever interested and wants to throw their 2 cents in.
For drilling/light duty work I planned on using a spindle speeder from a CNC with the Male 50 taper end ground into a Morse #5, I have a couple of them laying around from mold shops auctioning off surplus or going out of business back in the early 2000s. A 6 to 1 and a 4 to 1, thinking the 6 to 1 would be more than plenty good for what I would normally use this for.
About the only real issue with doing that, is I would need to make a telescoping arm that attaches to the headstock to hold the planet carrier and have some degree of travel. Say 6 to 12 inches more would be cool? Mainly for drilling and tapping, some light milling within the limits of what a ER40 will allow.
My other thought was to make an auxiliary attachment that bolts up to the faceplate, but tbh I dont forsee me needing speeds above 150ish RPM for the bulk of what I'll be using this for and that would be very involved. I'll be using it for mainly repair work and building new machinery to do field machining, and to add another thing I can do for customers. I currently do alot of portable milling/lineboring, Long term this will probably end up being a hobby machine after spring and we thaw out, I finally got permits to expand my shop with a foundation planned in for a HBM abit larger than this and a VBM if I can find a decent one that isnt completely clapped out.
For Rapids or the lack there of, I dont want anything lightning quick, but was planning on using some 1.5hp DC gear motors on the X and Z, I think purely for positioning that would be plenty, though any thoughts on that would be cool. The leadscrew for the Z runs far enough out the back and has a square that if I can come up with a motor mount on the bed I think that could work?
For faceplate/facing head and doing some larger diameter T lathe work in a pinch, I've got a 16" diameter chunk of steel laying around that was a cut off from a large shaft I made. If I make the T slot arrangement in such a way, I think I should be able to mount some of the facing slides I have for portable equipment. They operate off starwheels, so nothing fancy, but should work for work in the size range this machine will handle for facing.
And of course mount snout bars or boring mill chucking jaws.
Now a question for Tyrone, on the older Kearns machines how did the squaring table lift mechanism work? On Devlieg E style tables, a cam engages and lifts a ball bearing carrier that lifts the table and allows you to rotate it. Was the Kearns style similar? I'd like to try replicating that if at all possible. I really liked that functionality on the machines I ran with it.
And hopefully I'll have the tenacity to see this through to the end, Archie's project was a pretty involved affair and this seems to be an equally large endeavor.
Anyways thanks and if any of those ideas are just out and out bad, let me know, I am flying by the seat of my pants here, hoping I'll have some fun with it though, HBMs have to be my all time favorite shop machine.
With the amount of wear in the journals. Just saying.
