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Lathe - Spindle/Bearing

 
 

 

 
 
Spindle assembly (Mar 27, 2001) 10L spindle replacement (Oct 22, 2001)
Hot bearings in the south/Bearing with it (Jul 22, 2001) Binding (Dec 8, 2001)
 
Spindle assembly
I'm preparing to re-assemble the spindle of my 10K as soon as the capillary oilers come in. Reason for dis-assembly? I found there was too much play in the bronze bearings (up to .004), and I was unable to remove the shim packs due to somebody's over zealous paint job. After trying everything I could think of to no avail, I decided to just pull the whole thing apart for a good cleaning anyway. I'm glad I did. I found that the spring for the rear oiler had been damaged, and worst of all, the grease between the spindle and cone pulley had dried into a nice, stiff, waxy substance. No amount of new grease was going to get in there no matter what I did. I found the same to be true of the back gear shaft. Anyway, the reason for this post is to ask what grease to put in the rear thrust bearing. I know from the files and the postings I've searched to use Teflon grease between the spindle and cone pulley, as well as the back gear, (I've down-loaded everything to do with lubricating a SBL from the files,) but I've not found a mention as to what to pack the thrust bearing with. Also, does anyone have any tips on installing the capillary oilers? Should I soak them in the proper oil before installing them, or put them in dry and just fill up the Gits oilers? Any other pointers on re-installing the spindle would be helpful. Raymond (403)
I'm certainly no expert, but I just finished reassembling the headstock on my 9" SB. As per instructions I used the Teflon grease where indicated, and since I got little feedback when I posed the question to the group about the thrust bearing, I went ahead and packed the thrust bearing with the same Teflon grease. I don't have a grease gun for the Teflon grease, so I packed as much in as I could before assembling the back-gear or cone pulley and then used a syringe to inject as much additional grease as I could. I'll revisit that later. As the instructions say when reinstalling the spindle, keep the felt oilers retracted by using a piece of wire through the hole above oiler cap. I filled up the oil cavities before installing the spindle (otherwise filling would take longer), and I also put some oil on the bearing surfaces (both spindle and HS) before installation. Paul R. Hvidston (406)
Hot bearings in the south/Bearing with it 
Hey Dan 'n all, If you got a hot 'south-end' my guess is it isn't the thrust bearing, it's the main bearing. I would start with the wiggle test to see if you got play in the mains first. Put a bar in the bore with an indicator on it. Do this while the bearings are cold. Anything more then .0015 will need attention. Get a copy of the maintenance book from the company that covers your lathe. Follow the instruction. I got my book from them and it not only gives me the bearing info., but drawings and maint./lube. charts etc. Well worth the $25 I'll tell ya. As far as your thrust bearing is concerned, can you shuck it back and forth? If so there is a take-up nut on the outboard-side of the south main. An Allen wrench loosens the nut (a threaded collar really) so you can take up all but tiny bit of 'lash. Smear some grease on the exposed ball-race. Let it run up to temp. and check for heat again. If it's hot, back off on the collar a bit and re-check. Normally, bearings should be adjusted in a warm-up mode. IMHO. This way they have already expanded as much as they are going to. regards, Ron (1156)
Ron Lippard wrote: For some reason I didn't receive the original query, but Ron has covered the basics of the measurements quite well. If the spindle otherwise spins freely (no binding or high drag) when cold, then I'd flush the old oil out and use the Mobil I synthetic a number of us have been using for years. The newer 0W-30 seems the closest to the spindle oil viscosity that South Bend mentions. It will reduce your running temperature significantly, especially at higher speeds. If you're worried about suspended solids, you can drain the little reservoirs once a month by turning the oil cups upside down, but I've never bothered after doing it once, as the spindle bearings are a continuous loss system like the Bridgeport. The radial movement test on mine hasn't changed in five years, so the bearings are obviously staying in good shape. Mike (1157)
Jim, you may want to re-consider the idea. Before roller bearings were put into this size lathe, tapered bronze bushings were used. Actually it was the Celts of Europe prior to the Middle Ages who invented roller-bearings for their chariots! ANYWAY, Let's start with working with what you have there. Are your bearings loose? Is the head stock out of line? I think your best bet would be to either tighten your mains by using the peel-the-shim method or replacement bearings. This alone should solve your problem. You can always speak with tech-support at SBL. regards, Ron If at first you don't succeed, sky-diving is probably not for you. (1162)
Thanks for the posts advice on the brg/bushing ordeal with my model c lathe. As it turns out, I was able to adjust the slop out of my lathe, down to .002. The chuck was the real culprit! It'll have to be replaced. Jim (1166)
Jim, Good to see that you were able to solve your problem so simply. Conversion to roller bearings would have been difficult if not impossible and I'm not quite sure how to go about repairing the integral cast iron bearings in a model C, given that they adjust by pulling the casting together. Possibly by boring and pinning in a split bronze insert? Doesn't seem satisfactory offhand. Tom (1167)
My friend that owns a large machine shop says it can be done - line bore the casting, and install thin roller bearings. Luckily, I had the option I learned about from the board. I'm very grateful to guys like Tom and Tony that take time out of their busy lives and to help a newcomer. I asked for help on this problem on another board and was ignored. Jim (1168)
The following link http://people.ne.mediaone.net/wasser/SBLathe/index.html found in the bookmarks of this group shows a drawing of an underneath motor drive headstock with a split bushing. Does anyone have a detail drawing or knowledge of its design, such as is it grooved, plain, wall thickness and oiling method. I contacted one member off group that was kind enough to share with me his method of align boring his headstock. We discussed bearings and over size spindles, I prefer bushings I can knock out and replace when faced with the same situation again. George (1169)
Actually the making of a bearing replacement with a mill and a lathe isn't very hard. You can buy bearings that are close to the needed dimensions then the finish work on them is straight forward. Yasmiin (1170)
Yasmiin, I agree completely with regard to the machining. However, if you follow the link in George's post (nice info on 9" parts there) you will find that the bearing is made in one piece with a split. This presents some problems with locating and alignment not present with either a one piece solid bearing or a two piece insert. It Seems to me that the split bearing can only be rigidly attached at one point. It will have to slip a certain amount as the headstock bore is drawn down by adjustment. Some provision must be made to keep the axis of the bearing from shifting with relation to the axis of the bore and take up thrust (a shoulder perhaps?). Not at all impossible but requires some thought to make it work well. If anyone has been into one of the underneath drive machines, it would be interesting to know how SB did this. Tom(1172)
Tom, I am not sure that holding the bearing in place is necessary. The bore for the bearing is of course slightly tapered as is the outside of the bearing itself. I can't claim to have dismantled every machine with this type of bearing but the ones I have seem to depend on the friction of the bore on the bearing to hold them in place. It would be interesting to know if SB did this or did they put in something to keep the bearing from turning in the bore. I agree about the thrust part and there seem to be one adjustment for the bearing an a separate one creating the shoulder you mentioned as a second adjustment. I have one on my desk here that has a sliding collar held by some set screws that goes against the bearing adjustment. There are several pieces to this adjustment. One can see why a modern ball or roller bearing is a lot cheaper to build. Yasmiin (1173)
Wasn't there an article in HMS about this exact subject? Seems like the fix was to bore out the headstock casting till it was true, then true and sleeve the arbor to fit the bore. They didn't really get into any of the arguments surrounding changing bearing types or anything, just wanted to get back to like new clearances. (1177)
Yup, it was called something like "The Rebirth of a Model C" from an older HSM. As far as I can tell, there's nothing wrong with a hardened super-polished spindle running in a cast-iron bearing. Most cared-for 9" SBs are still in fine shape. When I got a different headstock for my 9", the spindle was scored so I tried to get another one from the seller (a guy who sells on eBay). The replacement he sent was in pristine shape, but the bearing surface diameters were too big and he never returned emails after that. I ended up getting another one from someone else and have stashed away that "too big" one in case I ever need to bore out the headstock. I keep the old scored one on hand to test the fit of the nose threads as I'm making chucks and closers. Paul R. Hvidston (1178)
10L spindle replacement
Anyone out there done a spindle removal replacement on a 10L? My 10L has a spindle with a 1" ID bore (1-7/8 x 8 tpi-not 5C capable). and I have a used spindle in good shape with the more typical and useful 1.375 ID bore (2-1/4 x 8 tpi-5C Capable!!). The manual doesn't give specific procedures for the R R. But does provide a procedure for adjustment of the headstock bearings. Any tricks, comments, or experiences anyone can relate to me before I make this change? Mark (1936)
Mark, I have included the four pages from the parts manual that cover the replacement of the spindle bearings. The procedure for replacing the spindle is basically the same. There are some thing to consider when replacing the spindle in a Heavy Ten (or any other lathe for that matter). The spindle you replace may have slightly different journal diameters, depending on the wear, manufacturing tolerance, etc. to the one you replace it with. This means that the shim packs under the bearing caps will probably need to be adjusted (either adding or subtracting shims as necessary for proper clearance). The Heavy Ten you have should have an "R" suffix in the unit code for your headstock. This is the smaller spindle Heavy Ten (1-7/8" x 8 t.p.i.). The "L" in 10L designates "Large Spindle" Heavy Ten (2-1/4" x 8 t.p.i.). The 10L is also listed for the other spindle types like L00, and 4D-1 Camlock. If your "new" (or should I say replacement) spindle already has its bearings with it, by all means use them. Just make sure that everything is clean and free of burrs. While you have the headstock apart, pull out your wicks and clean out the oil reservoirs, oil cups and the wicks. Use clean, fresh spindle oil when reassembling. I use Mobil Velocite #10 Spindle Oil. Spindle oil you use should comply with South Bend Lathe's recommendations of SUS 100 @ 100Deg. F. or ISO 22. There are several makes to choose from and can be had for about 10 buck a gallon (less shipping). This is about a lifetime supply for the average "hobby" lathe. Webb Attachment: (image/jpeg) SBL_10H_Spindle1.jpg [not stored] Attachment: (image/jpeg) SBL_10H_Spindle2.jpg [not stored] Attachment: (image/jpeg) SBL_10H_Spindle3.jpg [not stored] Attachment: (image/jpeg) SBL_10H_Spindle4.jpg [not stored] (1941)
Binding
I have 9" SB A model lathe. I bought it about 10 months ago and everything seem to be working well.I chucked in a piece to work on and brought the tail stock with a live center to stabilize the work. When rotating by hand I noticed that there seemed to a binding that hinders rotation. There is also a small thump when rotated by hand. When I pull the center back out of the work, rotation is free again. When I crank the center in again rotation is hindered again. I don't believe that I am putting to much pressure on with the tail stock. Steve (2360)
Steve, Could it have something to do with the spindle thrust bearing? Is there any axial play in the spindle, i.e. does it move away from the tailstock as the TS ram is advanced? The Spindle is captivated axially by a thrust bearing in one direction, and a fiber washer and clamp collar in the other direction. That's one reason why you always turn towards the headstock. Adjusting the clamp collar will remove the axial play, but if there's trouble with the thrust bearing there's not a whole lot you can do except fix it. BTW, we are assuming that you lube the center hole in the workpiece before bringing up the tailstock center, and that the center hole is drilled properly, and that the tailstock center is in good shape. Paul R. Hvidston(2361)
Have you taken your bearings apart for inspection. I have two South Bends that use bronze bearings. In their previous lifetimes swarf had somehow gotten into them and scored the journals. The journals then wore to correspond to the shape of the journals. Any end thrust from the tailstock tends to wedge the spindle into the grooves in the bushings. The only way I know of correcting this is to grind the spindle bearing surfaces true, then make a set of undersized bearing bronzes. Of course, your SB may have a different bearing setup than mine. Some SB spindles are supported directly by the cast-iron headstock--no bearing inserts. Orrin (2363)
Have you check the live center for a tight/bad spot? It might be that. As to the spindle, the washer that fits on the spindle nose right behind the threaded section is pressed on. It should sit just behind the shoulder that your chucks snug against. Its purpose is to keep swarf out of the bearings and minimize oil loss. If you are indicating this washer and have only 1/2 thousandth (.0005") of runout, don't worry about it. If you are indicating the shoulder the chuck registers against, then I would leave it alone. runout of .0005" here is allowable for an engine lathe. A "toolroom" lathe can allow around .0002" to .0003" runout here. But I would not go re-machining this shoulder if you are not experienced. One slip and you could ruin the spindle of your lathe. Also, I would check all other possibilities first. The thrust bearing on the spindle is open around its periphery and it is possible to get contamination in the bearing. To remove your spindle and clean this bearing is not difficult. 1) Remove the reverse tumbler assembly, 2) Loosen the pinch-screw on the locking ring and remove locking ring and fiber washer. 3) Tap the spindle with a lead hammer (or soft faced "deadblow" hammer) from the rear until the spindle is free from the Bull gear. 4) Carefully withdraw spindle from the headstock (try not to damage the bearings). As you slide the spindle out, remove the thrust bearing, step pulley, and Bull gear in turn as the spindle clears them. When replacing the spindle, the hardest thing is to do is get the woodruff key aligned with the slot in the Bull gear. Tap lightly and don't force it. If it doesn't want to go, pull it apart and check for alignment or burrs. When threading the lockring on to the spindle, you should tighten it just enough to prevent the left-hand bearing race of the thrust bearing (the side up against the rear spindle bearing casting boss) from turning when the spindle is rotated. Webb (2366)
 
     
 

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