PDA

View Full Version : South Bend 9" spindle maintenance, r/r



Evan
05-26-2011, 02:59 PM
I have been using my SB9 for about 30 years and it was in need of a new belt. I have never pulled the spindle so I figured I would kill two birds with one brick. By pulling the spindle I could replace the belt with an uncut/unglued serpentine belt, check out the spindle and replace the oiler felts at the same time.

Removing the spindle is an easy job. It takes all of 15 minutes and doesn't mess up any alignments. Before I did that I made some new shims in case I needed to adjust the clearance. It's a perfect job for CNC although it isn't very hard to do by hand, just tedious.

I stacked up a bunch of different thicknesses of brass shim stock, screwed them together on a board and cut them out with a very slow feed and a carbide cutter. They came out perfectly. Included at the bottom of these first 4 images is a scale pattern for the shims.

http://ixian.ca/pics8/spindle1.jpg

You can download a dxf file of the shims pattern here:

http://ixian.ca/pics8/sb9_shims.dxf

The first step in removing the spindle is to unplug the machine and remove the chuck. Next remove the gear cover by loosening the grub screw and lifting it off.

Then remove any gears on the banjo and the lead screw. Tip the banjo up so you can access the two screws holding on the circular guard, remove it and set it aside. Tip the banjo back and out of the way.

Refer to the next image and remove the indicated screws. The reverse gear toggle assembly pulls out of its socket in the head stock after the square head grub screw is removed. Remove the locking screw on the threaded spindle collar and unscrew it from the left of the spindle.

Place a board on the ways to prevent any chance of dropping the spindle on the ways. Using a block of wood, tap on the left end of the spindle to disengage it from the keyed bull gear and slide it out of the head stock. You may have to give it a good whack to get it started but there is no possibility of damage when driving it in this direction.

Inspect for wear, damage etc. I was very pleasantly surprised to find virtually no wear at all. Only the very finest scratches and some burnishing are present. No remediation is required and the cast iron bores on the head stock are just as good.

http://ixian.ca/pics8/spindle2.jpg

Since it was all apart I freshened up the paint using some very fast drying Krylon medium gray. I thoroughly cleaned it with, what else, trichloretheylene before painting.

Next was to make up some new felts for the oiler reservoirs. The old ones were in surprisingly good condition but since it is all apart new ones were provided. I know somebody is going to ask what sort of felt I used. It is machinery felt that I obtained from a machinery manufacturer that my wife represents.

Installing the felts requires that they be held out of the way of the spindle as it is replaced. The cast iron bores have oil return passages on both sides. Soak the felts in spindle oil until saturated and drop into place. A stiff wire, in this case mig wire, may be used to hold the felts down and out of the way. Depress the felt with a hex wrench and slide the wire into the felt. Put the wire on the outside on each end where it can be removed easily when the spindle is part way installed.

Clean and relube the thrust bearing with some wheel bearing grease. Then assemble the stack of the bull gearand the step pulley and install the spindle placing the thrust bearing when possible. Push the spindle into place until the key contacts the bull gear. Then pull out the wires holding the felts.

Turn the bull gear until you feel the key catch the key slot. No hammering is allowed in this direction because it will damage the thrust bearing. Instead, bring up the tail stock, mount the chuck to close up the distance and with a board or plate use the tailstock to press the spindle in place. Then replace the threaded collar, not forgetting the bearing shim. Tighten it very tight and then back it off until just slightly loose. You may need to use a punch to loosen after tightening. Punch against the excess threads on the side of the hole away from the securing screw head. This is a slightly fiddly adjustment because it tightens slightly when the screw is tightened. It should not produce any additional friction but it also shouldn't be loose.

Now is the time to replace the shims if necessary. There should be no perceptible looseness to the spindle at either end when a bar is installed in the chuck and used to lever it in every direction with the shims clamped down tight. However, the spindle should also turn freely at least a full turn when spun by hand.

http://ixian.ca/pics8/spindle3.jpg


I should mention, don't forget to put the belt in place before installing the spindle. If you are also changing the belt you will need to remove the back gear assembly too. It has a holding/engagement adjusting screw under the left end casting that must be removed. There is also a grub screw under the right end casting that must be loosened. The next is the only part where I ran into some slight difficulty. There is a tapered pin on the right end that holds an eccentric cam in place on the back gear shaft. I wasn't able to drive it out so I drilled it and replaced it with a roll pin. It isn't hardened and drills very easily.

All said and done except for replacing the left end parts. This is an easy job if the spindle is in good shape.

http://ixian.ca/pics8/spindle4.jpg


If the spindle has some slight damage then the cast iron bores will too. They can be cleaned up with a brake cylinder hone and the spindle polished with some emery if the damage isn't great. It isn't the optimum solution but it will prevent further damage and the lathe will be very usable as long as the shims are properly adjusted.

As a last test of the shims and clearance, oil up the spindle and run it for several minutes at high speed. There should be no perceptible temperature rise at either headstock bearing. If there is then add a couple of thou to the shim stack and test again.

topct
05-26-2011, 03:19 PM
That little hole above the oiler is where to stick the wire to hold the felts down while installing the spindle.

Evan
05-26-2011, 03:27 PM
Thanks. Why didn't I think of that?

RussZHC
05-26-2011, 05:34 PM
Evan:
if you would be so kind, can you please post the manufacturer of the belt and any number/letter coding?
I'm starting to look for a similar sized Sheldon but the mention of
"poly V" belts seems to confuse some...I've no clue how long a one I will end up needing and sort of hoping the code is as simple as regular "V" belts to "crack"...thanks.

garyphansen
05-26-2011, 05:45 PM
Evan:

Did you replace the fiber washer with two hardened washers and a roller bearing? I did that several years ago with mine and I would highly recommend it. Then you can tighten up the take up nut to remove all in and out play in the spindle. The parts cost me about $5 US at the time and I can look up the part numbers if you want. Gary P. Hansen

aboard_epsilon
05-26-2011, 06:23 PM
somewhere else ..is mentioned greasing the spindle with synthetic grease ..instead of using the oil hole in the pulleys.

every so often you want to pull the oilers out ..let the oil out and replenish with new stuff.perhaps tip the lathe forward to aid this...pump new stuff into the spring holder holes to flush out

mine is a bit noisy in back gear ..no matter how i adjust it ..the gears look unworn.....is this normal or are there more tips on getting it running quieter in back gear...it's whisper quite out of back gear.

i did the serpentine belt conversion on mine .when Evan first brought it up ..works well ..i also stuck one on the motor to countershaft ..

i also did the roller bearing conversion instead of the red washer ..just to add ..there is just barely enough room to screw the nut on the end of the lead screw after this conversion

when taking the spindle out of one that hasnt been taken out in years ..its not so easier a job than what it looks ./.the bull gear will be very tight on the spindle ..you may need a puller.

all the best.markj

Evan
05-26-2011, 06:55 PM
I replaced the fibre washer with a hardened metal one many years ago. I do have some extra thrust bearings though. I will check and see how that works. The spindle was tight on the bull gear but a good whack with a lead hammer solved that.

Russ,

The belt is a regular automotive serpentine belt. The length on the SB is entirely uncritical as it has lots of adjustement. The one I used is 46 inches but that depends on how far back the motor assembly is mounted. For a Sheldon just measure with a loop of string what you need.

Mark,

Spur gears are always noisy. Nothing will change that.

Chester
05-26-2011, 08:38 PM
Nice job Evan. I did mine last winter and used a length of 1/2-20 threaded rod to draw the spindle out into a length of tubing. Never liked that "hammering" procedure.

Evan
05-26-2011, 09:13 PM
A lead hammer is not at all like using a steel hammer on something. Also, when removing the spindle it isn't going to hurt anything. Lead hammers are the ultimate dead blow hammer.

It doesn't quite look like this any more but it still weighs the same. It's about time to recast the head.

http://ixian.ca/pics8/hammer1.jpg

macona
05-26-2011, 09:40 PM
Mark,

Spur gears are always noisy. Nothing will change that.

There are things that can help though. We have some lead filled open gear grease. Its amazing how much of a difference it makes. I think it is called Leadkote.

-Jerry

PeteF
05-26-2011, 11:11 PM
Evan:

Did you replace the fiber washer with two hardened washers and a roller bearing? I did that several years ago with mine and I would highly recommend it. Then you can tighten up the take up nut to remove all in and out play in the spindle. The parts cost me about $5 US at the time and I can look up the part numbers if you want. Gary P. Hansen

You beat me to it Gary, I was also going to suggest this as a very valuable and simple mod, I bought the bearing/washers from Enco IIRC, they just about paid me to take them off their hands! Replacement doesn't require spindle removal and takes about 5 minutes allowing a good 4 mins to turn the spindle after fitting the bearing and go "ewww" and "ahhh" a lot when you see how easily and smoothly it now turns!

Not sure about the wisdom of grease being placed anywhere there. As far as I know all the areas were designed for oil lubrication, and I can't see any good reason to start shoving grease in places it was never intended. It simply be washed out by the subsequent oil anyway.

Pete

Evan
05-27-2011, 12:06 AM
I knew somebody would comment on the grease. It is a long standing controversy if grease should be used in such bearings. I am of the opinion that a thrust bearing benefits from grease as the loads can be very high, especially when drilling. It won't wash out that easily as the bearing cage shields the races quite well.

1200rpm
05-27-2011, 05:26 AM
hi, i`m pretty new here so this might be a question that has been covered- your headstock has side oilers yet has what looks to be tapped holes on top of the bearings. what is the purpose of the holes? just curious, :)

aboard_epsilon
05-27-2011, 07:20 AM
Evans put a different picture up there ..than his actual head stock ..me thinks

well it didnt have them holes in it in 2006

http://bbs.homeshopmachinist.net/showthread.php?t=15209&highlight=south+bend

The Teflon grease idea (in the spindle area instead of oil through the lube point in the pulleys) is direct from the south bends literature.

Can be found on Steve wells south bend site..somewhere.

BTW ..there should be little horse shoe shaped clips in the headstock oil cavity, either side of the felt oilers, four in total....I know, these are fitted to the cast iron segmented bearing type lathes ..Evans is earlier type i think, has plain non segmented, before 1938 or there abouts,,,i don't know weather these lathes have the clips.

all the best.markj

PeteF
05-27-2011, 08:07 AM
Mark, I believe SB specifies grease for the spindle cone on an annual basis, yet their "oiling the lathe" bulletin says to oil the same points daily. No comments on the thrust bearing that I can find however. I guess at the end of the day as long as it has lubrication of some description it probably doesn't matter what's used. Fortunately your comments reminded me that I'd been forgetting about this point :eek: I rarely use the back-gear, but it's still something I just went out and gave a squirt. Cheers!

Pete

Edit: just to illustrate what happens if you don't oil these points, Hercus did a lathe as a clone of the SB9, and from that developed a mill that was pretty much just a lathe turned on end. They fitted it with zerk fittings for oil, however the fitting on the back gear cone pulleys was recessed and a standard gun couldn't get in there. The answer by the previous owner was to simply ignore it. When I stripped the mill there was signs of significant galling on the back gear spindle. It cleaned up just fine, and now properly lubricated (I replaced that fitting with a longer one) it doesn't affect the operation. But I can only imagine the commotion it must have been making when it was galling!!!

Evan
05-27-2011, 08:41 AM
hi, i`m pretty new here so this might be a question that has been covered- your headstock has side oilers yet has what looks to be tapped holes on top of the bearings. what is the purpose of the holes? just curious,

I drilled the holes during the maintenance because I am going to install top oil cups. I don't completely trust the felts to distribute enough oil. If you look at the drawing it has top oilers. That is the older model in the drawing. The only problem with the top oilers working alone is that they must be oiled every time the lathe is used. That isn't a problem for me, I am fanatic about keeping things oiled.

My lathe is a 1937 model. I suspect that the spindle has never been pulled before. The previous owner bought it new and used it a few times per year. I picked it up about 27 years ago. I sure would like to find a quick change box and lead screw for it. The bed already is drilled for installation.

I found a bearing for the tail of the spindle and installed it last night. Heck of a good idea. By itself that makes posting this worthwhile.

Failure to oil the cone pulley will eventually cause it to sieze to the spindle. That can make it near impossible to fix.

topct
05-27-2011, 09:16 AM
Is there a number for that bearing and the washers that go with it? At first glance at my SB9, there isn't much room for anything but a needle thrust type. The forward reverse tumbler looks to be in the way.

Rex
05-27-2011, 10:45 AM
Evan:
if you would be so kind, can you please post the manufacturer of the belt and any number/letter coding?
I'm starting to look for a similar sized Sheldon but the mention of
"poly V" belts seems to confuse some...I've no clue how long a one I will end up needing and sort of hoping the code is as simple as regular "V" belts to "crack"...thanks.

Russ, the Gates numbering system has the width and length built into the number. I can't find the "code" in the materials available to me here, but any parts store with an old-fashioned numerical listing will have a page devoted to the part-number code.

I measured the leather belt that came off mine and got a Gates serpentine as close as possible.

K060470 is 13/16 x 47.12

Note that the 470 indicates 47.0 inches (none seem to be exact) I think the 6 indicates the number of vees or ribs.

This is for a 9A with horizontal drive built in the 1950s. I have no idea if the mounting points are to "spec".

Right now I am using a segmented leather belt, one of those that you change the length by adding or removing segments. Works quite well, but I'll still probably pull the spindle and install the serpentine.

aboard_epsilon
05-27-2011, 12:21 PM
Is there a number for that bearing and the washers that go with it? At first glance at my SB9, there isn't much room for anything but a needle thrust type. The forward reverse tumbler looks to be in the way.
i just lifted this from the pm south bend forum

The bearing dimensions are 1 3/8" ID, 2 1/16" OD 5/64 thick.
the INA numbers on the bearing/washer are
TC2233 5988187
TWA 2233 6093850.

you need two washers

i could not find those ones in the uk..as im no wood worker :) ..so i took the head stock and spindle to my local bearing place they .measured and ordered .

all the best.markj

Rex
05-27-2011, 12:30 PM
Mark, I tried to cross those numbers to Timken with no luck.
Is the first number the bearing?
Is the washer specific to that bearing, like a race?

aboard_epsilon
05-27-2011, 01:02 PM
yep first number the bearing

washer is the race

all the best.markj

DICKEYBIRD
05-27-2011, 01:14 PM
Take a look here: http://www.use-enco.com/CGI/INPDFF?PMPAGE=1083&PMITEM=327-8039 bottom of the page.


Item #327-8040 and 2 of #327-8049 made by INA Bearing, good stuff! I bought some smaller ones for my CNC lathe project and a large assortment of the races just to have them around for fixit projects. Thin, hard washers come in handy 'round here!

topct
05-27-2011, 01:48 PM
The Enco bearings are too thick. The collar would not clear the tumbler.

RussZHC
05-27-2011, 03:36 PM
Thanks, Rex. Sort of info I was wondering about...

From what I can tell from Goodyear (Gatorback Serpentine) the coding is similar with the last 3 digits being the inch code (imperial) first 2 of 3 full inch, last of three fraction if applicable; with metric it looks to be just a direct length in mm (so 4PK0815 is 4 rib, effective length of 815mm).

Which leads to another general question, relative to the pulley width, how wide should said belt be? I seem to remember something like
4/5ths?

Asked as once you get to a certain length, belts can be found with 3, 4, 5 or 6 ribs and I assume getting wider (as opposed to smaller ribs in same overall width).

Oddly (?) Goodyear occasionally lists a belt on the chart I found with no ribs.

topct
05-27-2011, 04:14 PM
I'm running a Gatorback on my SB9. It is a 6 rib and measures about .850 wide. On all of the belts listed the the ribs are all the same size they just change the number of them. The SB pulleys are just a bit over 1 inch wide. 4/5ths the width of the pulley should be okay.

I ordered mine through Summit Racing.

http://www.goodyearep.com/productsdetail.aspx?id=3128

1200rpm
05-27-2011, 06:56 PM
i put the needle roller set up on my SB- can`t beat it for $6 -the MSC part #s are-
roller cage-# 03380979 (mfg # TC2233)
washer races #03381159 (mfg#TWA2233)
the manufacturer is INA

PeteF
05-27-2011, 09:29 PM
The Enco bearings are too thick. The collar would not clear the tumbler.

That's where mine came from and they work perfectly.

PeteF
05-27-2011, 09:44 PM
Just to confirm for those who may be left a little confused, the Enco part numbers are:
327-8040, "cage assembly" #TC2233 ID 1.375 OD 2.063; 1 Off @ $3.83 ea
327-8049, "flat race", #TWA2233 ID 1.375 OD 2.062; 2 Off @ $1.46 ea

Even if you don't order from Enco, that should be enough information to order from elsewhere. Total cost $6.75. Bargain!

Pete

topct
05-28-2011, 11:03 AM
The resident idiot has struck again. After measuring again, without the factory washer in place, that bearing will fit just fine. :o