isaaccarlson
Well-Known Member
1.75x8tpi and 1 1/16 bore. I put a 1" rod through it and it wiggled pretty good. Might be 1.120".
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Sheldon ks990 lathe?
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If you check the bore you may be able to get a little more room by running a hone through it and knocking off the rough interior. I did this on my uncles and it gave me the room I needed to to be able to insert raw blanks of the size I was using. Also just cleaned it up.
Can't wait to see it when you get done setting it up and doing some projects.
isaaccarlson
Well-Known Member
If you've got an honest 36" between centers you should be able to chamber medium length (24", maybe 26" but I doubt it) in the steady. Obviously, working through the headstock isn't going to be an option for most bolt action barrels. Shars does have a backplate available in 1-3/4 x 8 so that'll make it easy to fit a proper chuck.
Good luck with it!
Good luck with it!
isaaccarlson
Well-Known Member
I can fit normal barrels through the headstock just fine, even most bull barrels. It's the big heavy benchrest barrels that don't fit, and I don't use those since I'm not a benchrest shooter. I have never personally seen a barrel that would not fit through this headstock, except for the Quigley gun. That had a cannon barrel on it, lol.
Breech ends of some centerfires will not fit, but I don't need the breech end inside the headstock. I can make an extension for the ways if I ever need to chamber a long heavy barrel, or I might have a bigger lathe by then. It's not something I'm going to worry about.
I am currently working on getting the bearings shimmed up. The back gear shaft and lever were installed backwards, so he used a piece of wire to hold the gear "in" because it was not going past center on the shaft. The lever was right up against the spindle nose and was clocked wrong. I pulled it out and turned it around so it should work great now. I am going to get a wider belt tomorrow to replace the narrow little belt that was on there.
Breech ends of some centerfires will not fit, but I don't need the breech end inside the headstock. I can make an extension for the ways if I ever need to chamber a long heavy barrel, or I might have a bigger lathe by then. It's not something I'm going to worry about.
I am currently working on getting the bearings shimmed up. The back gear shaft and lever were installed backwards, so he used a piece of wire to hold the gear "in" because it was not going past center on the shaft. The lever was right up against the spindle nose and was clocked wrong. I pulled it out and turned it around so it should work great now. I am going to get a wider belt tomorrow to replace the narrow little belt that was on there.
isaaccarlson
Well-Known Member
I got the bearings dialed in to .0015-.002 clearance and the and play is .001+. It spins a couple of turns and then stops when spun by hand. Should I open it up another .001 or leave it? I think I might leave it and run it in while keeping an eye on bearing temps and see how it does.
I have a wider belt on order for tomorrow.
I have a wider belt on order for tomorrow.
isaaccarlson
Well-Known Member
I ran the spindle with my drill for several minutes at varying rpm's (500-2000, yeah, I know it only does 700 on it's own) and could not feel any heat in the bearings. The outboard bearing may have been a couple degrees warmer, but I was working with it not long before, so it could have been residual heat from my hand. I think it should be good to go. I'll get the new belt installed tomorrow and give it a good run.
I need to install an outlet and a couple of lights and then move the lathe to it's new spot.
I need to install an outlet and a couple of lights and then move the lathe to it's new spot.
Just let her eat Bud
I put some of these LED sewing machine lights on my small lathe and mill/Drill and they work great. Magnetic and you can get the light right where you need them. Gave some to my uncle and we put them on the big lathe and mill as well. As our eyes get worse it's hard to beat good light. They were only around $18 for 3 I believe from amazon.
Amazon product ASIN B01ACIFPYA
Amazon product ASIN B01ACIFPYA
I'm not trying to be argumentative, but I don't understand.
EVERY blank I purchase- regardless of manufacturer- has a breech cylinder that is either 1.200, or 1.250.
Yes- you can "choke up" and insert as far into the spindle as it'll go- but usually that leaves at least several inches outboard of the spindle unsupported.
How are you fitting a 1-1/4" barrel into a 1-1/16" hole?
shortgrass
Well-Known Member
If it has a 6", industry standard chuck on it, the hole in the chuck is 1 1/2". The "thickness" of a 6" chuck is approx 3 3/8"(depending on manufacture), not including the back plate if it has one. And, the jaws project from the face of the chuck, somewhat,,, another 1" or 1 1/4", maybe. All of the breech end will be in the chuck/back plate/ jaws, not the spindle bore.
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^^^
Fair point, but the further you get from the spindle, the greater your runout, and OP indicated he wanted to use an inboard spider.
Edited to add: see if you can find any info on oil viscosity for the headstock bearings. My SB uses a lighter weight oil than the 30 wt I was told to use on my Sheldon- naturally, the heavier the oil, the more clearance you need to maintain an adequate film. I would think that with the top oilers- which gravity feed the bearings (mine have wicks from a bottom reservoir) you can get away with the tighter clearances; again- depending on viscosity.
As you mentioned, the thing to watch is temp.
You might want to join the Sheldon group here, I don't know if you'll find anyone else with that model but worth a shot:
groups.io
Also, the antiques section on the Practical Machinist forum (largest in the world) is a good resource for general information:
You're likely not going to find any sort of manual, so in case you're not aware all of these old machines that rely on "total loss" lubrication (oil loss, that is) require frequent, heavy oiling so be sure to look for all of those lubrication points at bearings. My Sheldon didn't have as many capillary wicks as my South Bend- but still has some.
Some buy these old machines, oil em up and run them- figuring they'll last as "long as they last", and just make chips. If you're interested in going further than that and want to really preserve it for the long term (which is viable if the machine is tight and worth the effort), at least a partial disassembly is never a bad idea- particularly the apron.
Fair point, but the further you get from the spindle, the greater your runout, and OP indicated he wanted to use an inboard spider.
Wouldn't hurt to try to get at least the front journal a tad tighter, bronze shell bearings should be .0007-.001 according to South Bend specifications with a 2' bar in the spindle nose and 75 lbs of force on the bar.
Edited to add: see if you can find any info on oil viscosity for the headstock bearings. My SB uses a lighter weight oil than the 30 wt I was told to use on my Sheldon- naturally, the heavier the oil, the more clearance you need to maintain an adequate film. I would think that with the top oilers- which gravity feed the bearings (mine have wicks from a bottom reservoir) you can get away with the tighter clearances; again- depending on viscosity.
As you mentioned, the thing to watch is temp.
You might want to join the Sheldon group here, I don't know if you'll find anyone else with that model but worth a shot:
sheldonlathe groups.io Group
Sheldonlathe is for sharing information about Sheldon, Sebastian, and Vernon machine tools. The Files, Photos, and Links sections contain basic information. Members may upload machine photos to the Photos section. For a manual or parts for your Sheldon, check the Files for "Sheldon Parts FAQ"...
groups.io
Also, the antiques section on the Practical Machinist forum (largest in the world) is a good resource for general information:
Antique Machinery and History
Discuss antique machinery and the history of manufacturers >> moderator Greg Menke
www.practicalmachinist.com
You're likely not going to find any sort of manual, so in case you're not aware all of these old machines that rely on "total loss" lubrication (oil loss, that is) require frequent, heavy oiling so be sure to look for all of those lubrication points at bearings. My Sheldon didn't have as many capillary wicks as my South Bend- but still has some.
Some buy these old machines, oil em up and run them- figuring they'll last as "long as they last", and just make chips. If you're interested in going further than that and want to really preserve it for the long term (which is viable if the machine is tight and worth the effort), at least a partial disassembly is never a bad idea- particularly the apron.
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isaaccarlson
Well-Known Member
I can feel the drag increase as the clearance get's under .001. How much drag is acceptable?
shortgrass
Well-Known Member
I don't think the OP knows what he wants to do yet. Much has been regurgitated from what can be read on any gun related forum. I had 16yrs machining experience before I enrolled in gunsmithing school. Dialing in for me was no problem, but I watched others , who had NO machining experience, take a full 3hr class period and NOT get the piece dialed in, and end up frustrated even after repeated instruction. A 'spider' ain't no easier.. In the big picture of things, he'd be much better off with a good 4 jaw on a back plate. That's much more versatile than a spider. The first thing a novice wants to do when he gets his first lathe is "chamber barrels". He'd be much better off gaining some experience, make some tools, and learn what he can and can't do with what he has. As for the run-out, experience will teach you how to 'deal' with that! That little Sheldon would make an OK 2nd lathe, but I'd not want to rely on it for chambering, but I could if I had too. Learning on your own, off the web, just creates more mystique and in the end, bad habits and not so good conclusions as to "why" and "how". There are many ways to work around this little machines limitations, but it takes know how and experience, and a basis to start from. There's just about always a "work around". I just turned 65, and I've been machining in one form or another since '74. I can still learn something new. My opinion, a hobby gunsmith that has little or no practical machining experience will be much better served with a more 'substantial' machine to begin with.
