# Spindle bearing woes



## Izzy (Sep 27, 2018)

So about a year ago I bought and restored an old McKenzie lathe which the group was great for helping me with the questions I had. At the time I didn't do much with the spindle bearings other than set the oil clearance with shims and plasti-gage. The lathe ran great for the last year and I've made alot of parts with it since I've had it running but just recently I've been getting chatter and it's been getting worse and worse to the point where today I measured .015" play at the end of a 6" part. The chatter was too much I had to do something About it so I tore into it did some investigating. I measured .004" play at the spindle at both the front and back bearings. I also took the spindle out to get a look at things and measure. The spindle measured nice an round everywhere I measured. The bearings not so much... they're pretty scored along with the spindle and the bearings are measurably egg shaped.  The 2 numbers for the bearings where taken 90° apart,  I took a few more measurements that aren't written down. All the measurements are in the pictures Along with pictures of the bearings and spindle itself. What do you guys recommend be the course of action? The bearings where measure with no shims installed and bolts tightened down.


----------



## Izzy (Sep 28, 2018)

I don't know if I'm going about this the right way but I need the machine back up and running and with no advice yet I went out on a whim and stoned and polished up a bearing cap to see where that would get me. Here's what it looks like. Still unsure if I should even be doing this someone out there has got to have a light to shine on this.


----------



## Izzy (Sep 28, 2018)

I had the idea to get some Prussian blue and marking the bearing to the spindle I just don't know if this would be a good idea or not. There's definitely material that can be taken off the spindle doesn't move at all without shims under the caps. Is it possible to scrape them in new like that?


----------



## pontiac428 (Sep 28, 2018)

The usual treatment for a saddle bearing is to skim (grind) a tiny amount of material off the cap where the two mating pieces contact (along the "saw line" of the bushing), and then hone the bearing to size.  It will never be perfectly round, but you can get real close.  If I were to go that route, I would grind the spindle smooth on the bearing contact surfaces, measure it, then grind the cap and torque into place.  Then I would use a hone (if compatible with the bearing material) and hone out the bearing to match the spindle plus an oil clearance.  That's probably the best one can do short of taking the whole project to a better quipped shop.  Edit:  if you can separate the bearing from the saddle and cap, you can do the work on a lathe.


----------



## Izzy (Sep 28, 2018)

This is the exact kinda advice I was looking for I didn't know that was an option. Unfortunately I'm just a home gamer and this is my only lathe. The chatter was getting so bad I had to tear it apart to do something! I the only other machine I have is my Bridgeport. I don't mind brining the head stock and bearings and spindle to a shop and having them do the work but if there's anything I can do to minimize the cost or if I can do something with the Bridgeport? The headstock comes right off this old lathe...


----------



## Izzy (Sep 28, 2018)

She's pretty simple


----------



## pontiac428 (Sep 28, 2018)

Oh, I didn't realize the headstock was easy to remove.  An automotive machine shop should be able to do the job for you for a price that won't give you stomach cramps.  I'd hit the yellow pages and ask around, that should be an easy job to get done.


----------



## Izzy (Sep 28, 2018)

@pontiac428 well that puts me a little more at ease, thank you! So there's nothing that could be done by my hands either on the Bridgeport or with a little elbow grease? If not I'll call around. There's only 2 automotive machine shops in town.


----------



## BaronJ (Sep 28, 2018)

Hi Izzy,

You said the spindle binds up solid when you take the shims out.

Use a pair of feeler gauges on either side of the bearing cap to get an idea of how thick the shims need to be.  
Make quite sure that they go back on the right way round, the way they came off.
The technique is this rub the saddle and bearing on some abrasive paper, just to make sure the mating surfaces are clean.  
Re-assemble the cap and add shims (feeler gauge) until you have the clearance you want.
If necessary get or make some shims of the right thickness.  5 thou brass or steel shim material is quite common.
I wouldn't do anything to the shaft bearing surfaces unless they were really bad, and looking at your pictures they aren't too bad at all.
If anything I would say those bearings have been oil starved at some point.


----------



## Izzy (Sep 28, 2018)

@BaronJ if you look at my measurements for the spindle its got a high spot in the middle of the front bearing surface and I feel like this should be addressed while I have the spindle out. It's hard to see in the pictures but the spindle is pretty badly scored as well, my finger nail catches everywhere on it. I thought of maybe polishing it up with some Emery cloth using the shoe string method. I think I would have issues trying to set oil clearance when the bearings and the shaft aren't quite round, it would be easy to get false measurements.


----------



## BaronJ (Sep 28, 2018)

Hi Izzy,

I don't see a 3 thou high spot as an issue.  You will get that anyway because that is where the oil feed is.


----------



## Izzy (Sep 28, 2018)

So you say I shouldn't try to polish out that 3thou? Or the rest of the bearing surface to smooth it out? Just sand the bearing smooth and hone it to size? I could shave a bit off the caps as suggested by @pontiac428 with my Bridgeport.


----------



## Izzy (Sep 28, 2018)

It could be nothing but the bearings being so out of round and tapered like they are worries me. Also Due to the thrust face wearing out the high spot on the spindle doesn't spin in the center of the bearing anymore it's pushed back by about a 1/16.


----------



## BaronJ (Sep 28, 2018)

Izzy,  The 3 thou is nothing !  Don't even bother about it.

As far as shaving anything off the caps or bearing for that matter isn't going to improve things.  You have already said that the spindle binds up when you remove the shims !  In that case you need to add shims in order to reduce the effects of any wear.

Assuming your measurements are accurate the variation that you see in the caps is because they probably were not tightened down evenly.  Again the few thou difference could quite easily be due to the bearing cap being slightly twisted when fitted.  They are not doweled so there is no saying that when you replace them, that they won't end up being in a slightly different place.

I wouldn't worry about the bearings being slightly out of round !  They will never be truly round.  Worn thrust faces are another thing altogether.
You may need to make bronze thrust washers to sort that.

But lets do one thing at once.


----------



## BaronJ (Sep 28, 2018)

Izzy, Its my bedtime now !  We can follow up later.


----------



## Izzy (Sep 28, 2018)

@BaronJ thanks I appreciate the help so far! The lathe was restored about a year ago I did it myself and at the time nothing was done to the bearings other than shimming them to get proper oil clearance. I torqued the caps down myself so I know they where done evenly as I used a torque wrench. I measured the step for the bearing cap it seems like the cap itself is what's tapered not the bearing. Looks like this problem is unraveling itself...


----------



## Izzy (Sep 28, 2018)

My thoughts with the spindle binding up without the shims was that I could remove the shims and take out the extra material that causes it to bind. I just need to have this back up and running a bit longer. Then when the time comes, do as Pontiac said and have a shop skim the caps and line bore it back to size.


----------



## BaronJ (Sep 29, 2018)

Hi Izzy,

You need to think very carefully about this, once you remove material, *thats it,* you cannot replace it !

When the lathe was made originally, the bearings and caps were deliberately made with shims, not because they were cut wrongly, but because things wear.  The shims are there so that the spindle clearances can be adjusted to account for the inevitable wear that will take place over time.
The shims are usually, but not always, a stack of very thin ones, often only a thou or so thick, they can seem like one solid shim because they are compressed by the cap and tend to bond together.  

The normal way to adjust the bearings is to remove one or two shims at a time, measuring the spindle rotation as you go.
When the spindle becomes more than hand tight, put one shim back, and check again.  It is not a quick process !  I've seen engineers take days to shim shaft bearings.  This is why I suggested feeler gauges earlier, in case the shim was solid and not a stack.  Even compressing out the surface oil between the shims will affect the clearance.  

Whilst I think about it !  Carefully clean the oil drain hole in the bottom bearing.  The oil must have somewhere to drain.  Remember any dirt that gets into that top oil cup will get into the bearing and cause the scoring that you talk about on the shaft, and lack of oil is even worse because particles of the bearing itself will cause scoring.

When you put it all back together use plenty of clean oil, 10 or 20 SAE motor oil is perfectly fine.  If perchance you use multigrade, oil,  do not mix it or allow it to mix with detergent oils.  It will turn into a paste that won't lubricate anything.

I'll come back later and discuss thrust washers with you.


----------



## Izzy (Sep 29, 2018)

Yes I understand about the shims being there to take up wear over time. This is why I measured without the shims because at that point you've used up all your adjustment and need a more permanent fix per say. The thrust washer I can remake myself once he bearings are good enough I can use the lathe again. I would one day like to do a "real" restoration and get the bearings done properly. I really like this machine and I feel like if I had the bearings done properly the machine would cut much better and last another 100 years. I tried honing the bearings yesterday and i managed to remove alot of the scoring without affecting hole size too much. 
I've been using iso32 hydraulic oil on the bearings.


----------



## Izzy (Sep 29, 2018)

Also that isn't an oil drain hole, I thought the same thing but that's actually a pin I can only image to prevent the bearing from spinning. Oil simple runs out the sides of the bearings and honestly it runs through oil like crazy which is just one more reason I want to get this bearing situation all sorted out


----------



## BaronJ (Sep 29, 2018)

Hi Izzy,

Yes a lot of lathes use a total loss lubrication system.  My Myford is the same, oil comes out all over the place, the chip tray is swimming in the stuff.

I can't offer anything further.  Good luck with your repairs.


----------



## Izzy (Sep 29, 2018)

Well I spent most of the day trying different shims out in different spots. The front bearing has no shim at all now and the back bearing has about .015 in shims left. I got the side to side play down to 2.5 thou and the up and down play to a half thou or less but unfortunately the bearings and shaft are so badly worn that I can't get it any better than that. I'm afraid I'm going to have to get the caps skimmed and the bearings line bored as previously suggested


----------



## Izzy (Sep 29, 2018)

Here's how the bearings and shaft turned out after some light polishing and honing. I put the shims between the cap headstock is that correct or should it be between the bearing halves themselves? Seems like alot of the oil is coming out from the split in the bearings.


----------



## pontiac428 (Sep 29, 2018)

The shims go between the saddle and cap. What's going on in that last photo? Is that a shim? If it is, I'd make sure to have crazy glue and plenty of sterile suture and gauze really close by. It might be in backwards.

(from mobile)


----------



## BaronJ (Sep 30, 2018)

Hi Izzy,

Now that you have removed material from both the spindle and the bearings, you are going to have to get the cap and maybe the bearing mating surfaces machined to get back the clearance adjustment !  No shims means that you have got to the limit of how tight you can now get the fit.

I would suggest that 10 thou off the cap faces and a few thou off the bearing might get you back to a sane state.  Then add shims in 1 thou steps from 10 down.

The oil escaping from between the bearing split faces is because of the inevitable gap there.


----------



## Izzy (Sep 30, 2018)

@pontiac428 i had pulled the shims out to show where i was putting them. im no machine rebuilder by anymeans i just do this as a hobby so i wanted to make sure im doing things right. on a side note im assuming saddle=headstock? just to make sure we're on the same page here. 
@BaronJ the front bearing spun without shims before i did any honing or polishing its the back bearing that would bind up without any shims. im afraid im going to have to get the caps skimmed and line bored as both you and pontiac have suggested i just need to finish this part before sending my lathe off for repairs. do you reckon i could save a bit of money and skim the caps myself on the bridgeport then just have someone line bore the bearings and grind the shaft?


----------



## Bob Korves (Sep 30, 2018)

Also note that as the spindle moves up or down in relation to the headstock, it also moves in relation to the tailstock.  The tailstock center may end up too high and need work also.


----------



## Izzy (Sep 30, 2018)

yea im not looking forward to the tailstock adjustment after doing all this but the spindle is #1 priority. assuming i get the caps skimmed and the bearing re-bored ill probably have to lower the tailstock correct? how would i even go about doing that?


----------



## BaronJ (Sep 30, 2018)

Hi Izzy, Guys,

OK Izzy, do it the hard way !  

Use some 600-800 grit emery paper on a good flat surface, like a piece of plate glass.  Stick the emery paper down with double sided tape at the top and bottom edges.  Use oil to act as a lubricant between the work and emery paper.  All the oil is intended to do is to stop the emery paper surface from clogging up.  The oil will contain most if not all the material removed.  You must clean the caps/bearings thoroughly before testing.  The thing you don't want is transferring abrasive particles to the lathe spindle.

Rub the bearing cap on the emery paper, wipe it clean test with the bearing in place, and do it again, until you have a fit that you are happy with.
Do the front cap and bearing first.  Leave the rear cap off until you have done the front one.

Then leave the front cap off until you have set the rear one.

At this point you will have a known set of shims for both front and back bearings.  Now you can start to set the spindle clearances as you want them.
Either adding shims or rubbing off material from the caps.

The headstock is the part you are working on !  The saddle is the part that moves up and down the lathe bed.


----------



## pontiac428 (Sep 30, 2018)

When I spoke of the saddle and cap, I was referring to the two halves that enclose the bearing. The portion webbed into the headstock is the saddle, and the bearing cap is the cap. A lathe has its own saddle/carrier, but the conversation was about bearings so I didn't think clarification is necessary. Sorry for muddying the waters.

Sent from my HTC U11 using Tapatalk


----------



## Izzy (Sep 30, 2018)

@pontiac428 no need to apologise that's my bad for not knowing the proper terms I've just never heard it called the saddle before is all I've always known the saddle to be in the bed!
So I got the lathe back together I still have a ridiculous .01 of play at my part  better than the .015 from before but still giving me an uncontrollable amount of chatter. I'll have to go the skimmed caps and grinded shaft route.


----------



## Izzy (Sep 30, 2018)

Here's what I'm getting... The up and down play is next to nothing but the side to side play is what's killing me.


----------



## BaronJ (Oct 1, 2018)

Hi Izzy,

I'm also clarifying !  The picture you posted, I've modified to show exactly where you need to remove bearing material.

The parts that have the bolt hole through will need clearance so carefully just file a few thou off the wide flat faces so that you have space for shims.  The paint on the headstock part where the shim sits should be scraped off, it needs to be flat, otherwise it will tip the cap causing the shaft to be nipped at only one point.

When refitting, this is where your engineers blue helps.


----------



## BaronJ (Oct 1, 2018)

[QUOTE="Izzy,
So I got the lathe back together I still have a ridiculous .01 of play at my part  better than the .015 from before but still giving me an uncontrollable amount of chatter. [/QUOTE]

10 thou is ridiculous !  You need to get that play down to a thou or less.  From looking at the picture you posted of your turned surface, you have a lot of work to do !

You have removed so much material from the spindle bearing surfaces, that you are going to have a hard time getting back to the correct clearances.


----------



## tq60 (Oct 1, 2018)

Time for a beer...

Once finished cut the can to make shims to go under the bearings as this will close them up.

You will need to skim the ends to get vsps to Close

Sent from my SAMSUNG-SM-G930A using Tapatalk


----------



## Izzy (Oct 1, 2018)

@BaronJ  you said I should take about 10 thou off the caps, couldn't I just do that in the Bridgeport? Seems like alot to file off.
There is no paint on the mating surfaces of the bearing cap. You mentioned the cap needs to be flat, it's got about a 20thou taper? the cap itself has pretty bad taper to it on its own should I try to get that out too?


----------



## Izzy (Oct 1, 2018)




----------



## pontiac428 (Oct 1, 2018)

Izzy, you should really stop trying to remove material.  You're on your way to making a mess of the most sensitive part of a lathe.  You won't get what you are after working with abrasive cloth, and certainly not "by eye".  Bearings and spindles are something that require attention to the .0001" in squareness, roundness, thrust, and concentricity.  It takes more than your bench calipers to measure.  If you stop while you are ahead, you can probably still use those bearings and spindle- after they've been re-bored in a shop set up to do the job.  Hopefully you haven't hit the point of no return with it.


----------



## BaronJ (Oct 1, 2018)

Hi Pontiac, Izzy,

I fear that too much material may allready have been removed from both the spindle bearing surfaces and the bearing caps anyway.  Without a gap between the faces that the bolts securing the caps go through, the bearings are not going to be able to collapse enough to grip the spindle.

Unless the headstock itself can be mounted on the mill and guaranteed to be square then taking a few thou off the top with a file is one option. 
Unless you have a gap when the cap is fitted, there is no way that you can reduce the play in the spindle.
Once you have that gap the bearing can be closed up by very carefully rubbing down the cap faces. 

Lapping split bearings using abrasive paper is very much a common way of removing very small amounts of material.  But it takes some skill and a lot of time.  The workpiece has to be kept flat and the downward pressure kept uniform across the work. 

I also doubt that spare bronze bearing shells are available for this lathe, because new shells would be able to be adjusted to suit the spindle.  That is assuming that the spindle is still round after being cleaned up.


----------



## Izzy (Oct 1, 2018)

I mostly just knocked off the tops of the ridges, I removed a thou or less of material I honestly didn't take off much. I did more polishing than anything else. I understand that the spindle is the most important part which is why I'm asking for help but you honestly don't need to be measuring in the tenths to see a 20thou taper. my point is if it's measureable with calipers then it's probably pretty bad considering it should be in the tenths as you said which it's no where near that. I'll take everything apart and get new measurements and report back. I may have found a shop that will be able to line bore the bearings so it's gotta come apart anyways.
@BaronJ  unfortunately this was more or less the condition I got the lathe in a few years ago. When I first got it, all I did was adjust the shims and it ran great for the last 2 years or so the front bearing only had a couple thou of shim stock between the caps when I got it. The head stock does come off and it could be mounted on my mill it's only held in with 4bolts and it mates with the bed of the lathe so I would assume the bottom to be flat.


----------



## BaronJ (Oct 1, 2018)

Hi Izzy,

OK !  Lets stop at this point and do nothing else!

I want to make sure that we are both talking the same language.  Refer to my picture.

If you remove the headstock and place it on your mill table, making sure that everything is clean and there is no rock.  No need to clamp anything down for the moment.  Using a dial gauge in the mill spindle, measure the hight differences on each of the pillar surfaces, at each end of each of the four and in the middle where the bolt hole is.

I am not interested in the hight from the base of the headstock casting.  I'm just wanting to find a datum point.
So if the front left, left side is considered zero.  What is the middle and right edges.  Plus 1 thou, minus 1 thou or nothing.
Without changing the gauge hight, compare the other pillars.

Do a sketch and write the figures down.


----------



## BaronJ (Oct 2, 2018)

Hi Izzy,  Please let me know when you are ready to move on.


----------



## Izzy (Oct 3, 2018)

Ok so here's what I got. First picture is exactly what you asked for I checked it with dial test indicator. The surfaces where no where near flat. They had a taper going into the spindle by about 3thou which I've marked in the paper. Second picture is my new measurements of the spindle and bearings again measured without shims to stay consistent. I used my mitutoyo mic for the spindle and a Lufkin inside mic for the bearings. Last image is of the setup.


----------



## BaronJ (Oct 4, 2018)

Hi Izzy,

Have a look at this and confirm that you have made the "Right Rear" pillar the zero reference !  The lowest point on the pillars.
Are are the figures you have written the differences from the zero reference ?
I'm assuming that this is looking down onto the top of the headstock, and that it is down flat with no rock.


----------



## Izzy (Oct 4, 2018)

@BaronJ yes that's correct it's a birds eye view and all numbers are in reference to the datum as you asked. And no there is no rock from the headstock it's firmly planted on the table


----------



## BaronJ (Oct 4, 2018)

Hi Izzy,

That is some wide range of hight variation !  I would have expected 8 or 10 thou, but 30 thou !  That is some range.
Ok, back to the job in hand.

If I said take a 10 thou cut right across all four pillars on the mill without altering the cutter hight, could you achieve that ?


----------



## Izzy (Oct 4, 2018)

The lathe is from 1920 it looks to me as though the tops have been done using a shaper. Those straight across cut marks are easy to tell. I was almost at the limit of my DTI! I was surprised myself. 
Absolutely I could do that so 10 thou from the 0 point? Meaning I'd be taking off 40 on the right front?


----------



## BaronJ (Oct 4, 2018)

Hi Izzy,

No, your are right, Ive got it wrong !  I was using the datum as zero to take a cut off the tops. Which is the wrong direction.
It needs to be using the tallest pillar and then take 10 thou off.

What I'm trying to do is level the tops of the pillars.  I was going to do it in 10 thou steps.


----------



## BaronJ (Oct 4, 2018)

So if you take off 10 thou that would reduce the right front pillar from +30 thou to +20 thou.
And reduce the left front pillar from +23 to +20,  the left rear pillar from +26.5 to +20 thou.
The right rear wouldn't be altered.

I hope I've got it right this time.  I'm glad you queried it.

Only take a single cut and remeasure.


----------



## Izzy (Oct 4, 2018)

Gotcha, I understand what your doing. I can absolutely do that. I'll take the cut and report back. 
Thanks for having the patience to walk me through this, I only wish there was some way I could repay the favor!


----------



## Cadillac (Oct 4, 2018)

I would check the tram on your head and make it as perfect as you can get. Then redo your measurements just to be sure. Don’t look at old numbers start fresh and compare before  your first chip.


----------



## BaronJ (Oct 5, 2018)

Hi Cadillac,

Yes I agree !  These are all things we do without giving any thought to them.  The old adage, measure twice cut once, applies.

With those pillar height's varying like that, it makes me wonder what the bearing caps and shells are like.


----------



## Izzy (Oct 5, 2018)

@BaronJ  I was curious about the caps myself which is why I took a quick measurement with my calipers. I went to KBC today and picked up a spindle square to make sure the head was perfectly trammed. I have some work to do to my vehicle before getting to the head stock but I'll report back as soon as I've taken my cuts.


----------



## BaronJ (Oct 5, 2018)

Hi Izzy,

No worries I'll be around.  I'm as keen to find out as you are.


----------



## Cadillac (Oct 5, 2018)

BaronJ said:


> Hi Cadillac,
> 
> Yes I agree !  These are all things we do without giving any thought to them.  The old adage, measure twice cut once, applies.
> 
> With those pillar height's varying like that, it makes me wonder what the bearing caps and shells are like.




I would bolt the caps down and torque. Then I would put vertical in my BP and take readings with a .0001 indicator. That’s gonna give you some insight as to what’s going on. Then I’d mic the spindle. If it’s tapered that’s gonna dictate what I’d do. 
 If tapered I’d have it ground straight then have the headstock linebored and be done. 
 If spindle is straight I’d either bore it myself and leave a little in case it doesn’t work right and then suck it up and have linebored.
  I would think it can be done with a lot of careful measuring. Remember you can’t redo once you cut so be confident before you start. No room for rushing anything with this. Good luck.


----------



## Izzy (Oct 5, 2018)

@Cadillac I believe that's what we're working towards, just trying to save a bit of money by shaving down caps/headstock myself before dropping if off for line boring. The old mold shop I used to work for said they could do it for me. The measurements for my spindle are a few posts up. It's got a belly in the middle for lack of better words.


----------



## BaronJ (Oct 5, 2018)

Line boring won't help !  Neither will bolting the caps down and measuring them.
If you can get replacement bronze shells then you might get away with doing a line bore job.
Material has already been removed from both the spindle and the bearing shells.  You cannot put that material back.


----------



## Izzy (Oct 5, 2018)

I thought that's what we where working towards. I thought we where removing a bit of material to then get it line bored since the play is in the sides not up and down. I thought line boring would give us a true and straight hole for the spindle?


----------



## BaronJ (Oct 5, 2018)

Hi Izzy,

You have already removed material !  We now need to find out how much we have got left to play with.  Taking 10 thou off the pillars is going to allow you to assess what material you have left and what you can do to start to restore things to a workable state.  That 10 thou may not be enough !
Since based on the measurements that you took, after removing 10 thou the pillars are still going to be high so there is room to do more if needed.

Sorry Cadillac, but your advice is unwise at this point !


----------



## BaronJ (Oct 5, 2018)

Izzy,

You will need feeler gauges, engineers blue and a pair of inside calipers a bit further on.
The belly on the spindle is of little concern at the moment.

I'm going to bed now, but I'll be around tomorrow...


----------



## Izzy (Oct 7, 2018)

So today I got a chance to get my car back together, clean off the mill table, tram the head (good thing I did it was out .01) and took a cut on the head stock.
The left side bearings are now showing an even +10 all around the right front is +13 all around and the right rear didn't get cut But, we knew that going in. 
I've got all that stuff. I used to work at a plastic injection mold shop so I've got a decent amount of 0-12" measuring tools a set of gauge blocks a matched pair of V-blocks. Anything else I might need I don't mind adding to my collection!  
So what's the next step?


----------



## BaronJ (Oct 8, 2018)

Hi Izzy,



> The left side bearings are now showing an even +10 all around the right front is +13 all around and the right rear didn't get cut But, we knew that going in.



We now need to find out how much we have left !
Don't put the spindle back in.  Place the caps on the headstock and see what the gap is between the bearing shells if any.  Both at the chuck end and at the tail end.  Measure with a feeler gauge at both ends of the bearing shells.

I'm working towards reducing any gap to zero and looking to have a gap between the top of the pillar and the cap, however small.


----------



## Cadillac (Oct 8, 2018)

Assemble the caps and check the bore now? Torque caps to get a consistent reading. See if you’ve changed the taper. 
 I’d get some dykem or canode to blue your surface to check contact.


----------



## Izzy (Oct 8, 2018)

I put the caps back on and the bearing halves are now contacting and there's a gap between the "pillars" and the caps albeit not even what so ever but, there is a gap there. The Gap is tapered enough that it can be seen by eye though. I didn't torque the caps down in fear of cracking them with the Gap that was there. Here's what I measured with feeler gauges and caps not torqued down. I can re-measure with the caps torqued down if necessary just didn't want to risk it without asking first. I don't want to screw anything up.


----------



## BaronJ (Oct 8, 2018)

Hi Izzy,

Thats good !  I'm glad that you didn't risk cracking the caps, it would have been game over.
The measurements with the feeler gauge, is that the gap between the bearing shells along the line of the joint.


----------



## Cadillac (Oct 8, 2018)

I would not torque them down yet. I would think you need to now correct the caps straight surface. Trying to shim a taper on 4 corners that arnt equal is gonna be a nightmare. 
 I’m thinking of this as connecting rods and crankshaft main caps which I’m very familiar with. Those caps need a flat and parallel surface to mate too. With the cap being taper you will never get even load on the bearing causing premature familiar. 
 As for how to get those surfaces parallel with the bottom. I would try putting the assembly on a flatest surface you have. While having caps on I would use a height gauge and go around the assembly finding the highest point on caps. Then scribe the others to match that height. Then align on mill and level them out. 
 Then you will be able to use know shimstock and make up the difference not worrying about front to rear being off. Just a idea.


----------



## BaronJ (Oct 8, 2018)

Cadillac said:


> I would not torque them down yet. I would think you need to now correct the caps straight surface. Trying to shim a taper on 4 corners that aren't equal is gonna be a nightmare.



I agree, its going to be an issue to be sorted, when we get to it !



> As for how to get those surfaces parallel with the bottom. I would try putting the assembly on a flatest surface you have. While having caps on I would use a height gauge and go around the assembly finding the highest point on caps. Then scribe the others to match that height. Then align on mill and level them out.



The problem with doing that is we don't know how the shells have worn !  At some time in its life the caps have been assembled using those surfaces, we need to find out if the shell wear is even or canted crooked.  All we have at the moment is some surfaces that we know are flat.



> Then you will be able to use known shimstock and make up the difference not worrying about front to rear being off. Just a idea.



Down the line the use of shims will probably be required, and parallel surfaces would be an advantage.


----------



## Izzy (Oct 8, 2018)

The gap was measured between the bearing cap and the "pillars" of the head stock as you called them before. The bronze bushings themselves dont have a gap anymore they are touching.
@Cadillac I'm a licensed mechanic and almost went through for my general machinist license as well and i view the spindle vary similaryily like you do, just like a crank shaft. Both have caps and journal bearings and require extreme accuracy for a long life. Either way I'm ready and eagerly awaiting the next steps!


----------



## BaronJ (Oct 8, 2018)

Hi Izzy,

Good, I just needed to confirm that the bearing shells were meeting without any gap, and that the gap was between the top of the pillar and the cap.

Use calipers to measure down the inside of the bearings at 90 degrees to the shell joint faces.  Whilst the actual diameter isn't important at the moment how parallel the bearing is, is.  If you can get an accurate diameter then all well and good.    

As Cadilac mentioned we are going to have to sort out the taper on the faces of those caps.  Can you post a couple of pictures of them, top, front and sides please.


----------



## Izzy (Oct 9, 2018)

Alright so I took a bunch of measurements today and I got the pictures you wanted. Just to verify the first picture is the measurement you where looking for? If so the next pictures have all my measurements I also measured the bearing caps with a mic out of curiosity. I think we can gather from this that it's the step in the caps that are tapered. Let me know what you think and what my next step is.


----------



## BaronJ (Oct 10, 2018)

Thanks Izzy,  That's brilliant.

Remeasure the tops of the pillars please !  I want to make sure that I'm right.

I'll assume that the bearings themselves are parallel to the line of the spindle.

Earlier you said that the tail bearing would bind up the spindle when you took the shims out.  So lets correct that end first.
You can do this two ways.  You can use a feeler gauge to determine how much out of parallel the cap and top of the pillar are or you can use plastigauge to do the same thing.  Either way you need to correct the tail pillar and cap surfaces, so that you can make up new shims.

Now I know that we only took a 10 thou swipe off the top of the pillars, and that they are not flat all the way across, but if the bulk of the top of the pillar is flat I wouldn't remove any more material.

The way to get the caps flat is to put them into the mill vise and use the bearing shell edges to get the cap level in both directions.  The fact that the caps are rectangular is nice insomuch as you have flat surfaces to grip in the mill vice.  Do not take any material off the bronze bearing shell or the supporting edge,  That shell edge is the only reference surface that you have.

Note that all this is without putting the spindle back in the headstock.  Measuring with the spindle in place comes later.

The aim is to have the bearing cap supported on the edges of the bronze shell and the gap on top of the pillar supported with a shim in between.  Ideally without any rocking of the cap.  If you need to use the hold down bolts only make them finger tight.

Next we will sort the front bearing out.

I'll be around later on.


----------



## Izzy (Oct 10, 2018)

So I'm gonna be taking a cut off the caps mating surface?
The rear cap itself is pretty square though, it measured 1.550-552 all around it was the shell edges that had taper to them, all of them had 10thou or more.
I measured the pillars as carefully as I could with calipers anyways. I'm pretty confident in those numbers I can get a depth Gage if it needs to be more accurate. 
the front bronze bearing sits slightly above the cast iron surface I measured to the bronze surface. Not sure if that's correct.


----------



## Cadillac (Oct 10, 2018)

Looks like some progress. I would definately get a depth gauge. The more accurate your measurements the better the outcome. You want to measure in tenths if possible. 
 The ledge on the inside of caps where bearings sits flush with would be a good reference point to level the caps. I’d put a parallel spanning the gap and then dial it leveling to mill. Obviously don’t put in vise in direction of bearings it will distort cap. I’d make both caps the same or at least that would be the goal. Good luck


----------



## BaronJ (Oct 10, 2018)

Hi Guys,

Yes the bronze shell edges are the only reference point on there.  So getting a parallel mating surface would be good.
I can't suggest anything for the front rear pillar other than that is going to need a thicker shim on one side.

Cadillac: Yes a piece that sat across the edges of the shell that was like a parallel would be a great help in getting everything square.  Then squaring up the mating faces.

If we can get the pillars and the cap mating surfaces square then we are on the way to being able to start and align the bearings to the spindle.
Basically we are going back to the condition when the lathe was first made.

In this case the tail bearing has much less wear than the chuck end and should be the easiest to setup.  The chuck end is going to be difficult because of the badly fitted cap and how much the bearing shell is tapered.

I'm being very cautious about removing material, it would be easy to screw it up.

With regard to the "Primary" shims, primary for want of a better word. Are there only to provide the starting point for bearing adjustment.  I would suggest thin aluminum plate, rubbed down to fit the gap, with steel shim material for fine adjustment.  If I'm right it will be a matter of adding just a few thou of shim.


----------



## Izzy (Oct 10, 2018)

Ok so let me make sure I understand, it doesn't matter if the caps mating surface has a taper in it as long as the mating surface is parallel with the shell edge?


----------



## BaronJ (Oct 11, 2018)

Hi Izzy,

All the edges ideally should be parallel to each other.  When you come to fit the caps with the spindle in place the shells, with the shims, need to come together square even if they don't actually meet.  You want to avoid having the bearing shells lifted at the front or the back when the cap is in place.

This is why I said that if the bulk of the top of the pillar is flat.  

Now if there is only a small area that is flat, you will need to take a few thou more off to get that greater area.  At this point the fixed shell edge and the top of the pillar should be parallel.  So if you now put the cap in position it will rest on the shell edges and the gap for the shim can be assessed.

When the spindle is in place you will need to blue up and discover where you need to scrape.  The tail bearing should be easy to set, its the front one, chuck end, that is going to be difficult.


----------



## Cadillac (Oct 11, 2018)

Just thinking here. What if you took the caps and removed the bearings. Then take gauge blocks or set up blocks and mount caps to mill table. Machined side down so reference ledges are on set up blocks. Bolt them down lightly. Then take a woodruff key cutter or slit saw and cut the taper surface flat. That should bring all them surfaces parallel to each other. Then you should have a good starting point to check fitment of bearings to spindle.


----------



## BaronJ (Oct 13, 2018)

Hi Cadillac,

Really the aim of the whole exercise is to be able to scrape the top shell in to suit the spindle, without altering the spindle center hight.  The rear bearing seems to still have some adjustment in it, whilst the front bearing is badly worn.  The sloping surfaces on the bearing caps don't help ! Making the gap between them larger will allow the bearing shell to come down and contact the spindle, which can then be blued and scraped to suit. Properly shimmed and done carefully would restore the lathe to a good working condition.

I did have a natter with an old time friend of mine, to whom I was discussing this thread, and he commented that in his day, you would have had the shells white metaled and scraped to suit.  But no one does white metaling anymore.


----------



## Cadillac (Oct 13, 2018)

So I understand this correctly. The bearings do mate together parrallel and flush with each other? It's the caps of the bearings that have a taper to the horizontal surfaces that mate to the headstock. Hope I described that clearly? Then work can begin on bearing fitment to spindle by means of scraping.


----------



## Izzy (Oct 13, 2018)

Sorry guys been busy lately but I think I better understand what's going on. So my next step would be to mill the slope off the bearing caps then blue up the spindle and scrape to size? 
I thought about Babbitting the bearings but I think ultimately after this I'll probably make new ones the way things have been going for me I'll probably be working for the ole mold shop again then I'll have all sorts of machines at my disposal  they allow you to use any machine you want when you're off hours so long as it's not being used for a job.


----------



## BaronJ (Oct 14, 2018)

Cadillac said:


> So I understand this correctly. The bearings do mate together parrallel and flush with each other? It's the caps of the bearings that have a taper to the horizontal surfaces that mate to the headstock. Hope I described that clearly? Then work can begin on bearing fitment to spindle by means of scraping.



Hi Cadillac,  Thats about the size of it.  You're never going to get the bearing shell truly round, and really very carefully scraping in is about the only real way of getting a good shaft to shell fit.  Without the ability to close up the shells, you won't be able to discover where to scrape.

If the shells meet without grabbing the spindle shaft, then the only place you can remove any material, is from the mating edges of the top shell.


----------



## BaronJ (Oct 14, 2018)

Izzy said:


> Sorry guys been busy lately but I think I better understand what's going on. So my next step would be to mill the slope off the bearing caps then blue up the spindle and scrape to size?
> I thought about Babbitting the bearings but I think ultimately after this I'll probably make new ones the way things have been going for me I'll probably be working for the ole mold shop again then I'll have all sorts of machines at my disposal  they allow you to use any machine you want when you're off hours so long as it's not being used for a job.



Hi Izzy,  

Yes you have got it !  But don't forget the shims !
If you really wanted you could actually fit roller bearings, it might be easier than trying to reproduce those bronze shells.
Nice about getting back into the mold shop, its good that you have the use of the machinery there.  I do miss being able to use some old friends, now departed, workshops !  Working alone can be a bit soul destroying.


----------



## Izzy (Oct 14, 2018)

@BaronJ I know exactly what you mean I work alone alot! And usually when I want to learn something i try to teach myself as best I can by watching videos and reading articles and such. Part of the reason I'm here asking for help is cuz I dont really have anyone else to turn to for advice this was sorta my last chance at trying to learn something new so I could fix the thing. I wouldn't mind going the roller bearing route although I don't think I'd have a problem producing those shells so long as I have a machine to do it on. Some of the jobs we used to get had half thou tolerances and i could make it happen. 
So as far as scraping goes I've never done that, I've heard I could grind and hardned an old file to do the job? I'm gonna need a crash course on scraping before I get there. I understand the blueing and marking process, its the actual motions and mechanics of it that I'm unsure of. And how to shape my scraper?


----------



## BaronJ (Oct 14, 2018)

Hi Izzy,

Thank you for your nice words.  As you have probably gathered by now, I'm getting a bit long in the tooth, so hands on is becoming hard work.

If I can find my scrapers, I'll take a picture and post it.  They are quite straight forward to make, but you are going to need a curved one with a fairly long narrow end.  My scrapers are Starret ones, passed down from my Grandfather.  He was a mining engineer.

When you get around to bluing up take some pictures.  You probably won't need to take very much material off and it will primarily be in the center part of the shell.

Don't even think about taking any material out of the bottom half's at all.  Doing so will alter the lathe spindle center hight, which you definitely don't want.


----------



## Izzy (Oct 14, 2018)

Absolutely not touching the bottom bearings, just the tops! My sister is getting married in the next couple weeks so things have been hectic for me but, I'll report back when I'm at the blueing process.
Just out of curiosity how would I go abouts converting it to roller bearings?


----------



## BaronJ (Oct 14, 2018)

Hi Izzy,

Seriously !  I wouldn't.  You would have a major machining job on both the spindle and the housings.  Plus you could easily be talking several hundred dollars for a single bearing, never mind two of them.  You would still need a pair for the tail end of the spindle.

It was a little naughty of me to throw that into the mix.  My apologies.

Congratulations on your sister getting married.  Best thing that ever happened to me.  Coming up nearly 50 years.  How time flies.

As far as your lathe is concerned, think about what you are doing, what you need to do and how you are going to do it, and it will work out just fine.


----------



## Izzy (Oct 14, 2018)

@BaronJ I just did some reading on converting a plain bearing lathe to roller bearings and I'd have to agree! I think  when the time comes I'll stick to just making new bronze bearings  I'd like to keep this lathe tho it's a real piece of Canadian history I've only ever talked to one other person who has one of these and he's in Quebec!


----------



## BaronJ (Oct 15, 2018)

Hi Izzy,

Pictures of one of my curved scrapers, as promised !



As you can see the blade is 5.5" inches long plus the handle.  Its only the end 1.5" inches or so that is used.
I believe these scrapers to be over a 100 years or so old.  I think there were six in the set, but I was only able to locate four of them this morning.
I think it is the large and small triangular section ones that have gone missing.  There is one large and one small curved one, this one and a large and a small square ended ones.  I also have a Sandvic one which takes carbide tips.


----------

