# Standard Modern 11" Series 2000 Lathe Spindle Issue



## Crosche (Mar 30, 2020)

Hey all,

I set up an indicator on a piece of 1 1/2" stock that I was turning and found that it had a high spot that became more pronounced the further out I measured. This lead me to pull off the chuck and measure the spindle nose, which when I did I found a high spot of 0.0005". So, at this point I am at a bit of a loss as to how to correct the problem. I am not sure if I should adjust the spindle bearings or if the spindle is buggered or if it is the D1 collar that is attached to the spindle. Any of you guys with Standard Modern lathes have any suggestions?

Thanks,

Chad


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## RobinHood (Mar 31, 2020)

Hi Chad,

so you were basically turning an “egg shaped” part?

did the high spot on your work match the high spot you measured on the spindle nose? if that were the case, I would look at the bearings. also check the spindle for a bend.

a straight spindle running true in its bearings should give you round work even if the nose had runout.

i believe the D-1 collar is integral to the spindle. at least it is on my SM1120, SM1340 and the Colchester. it looks on my lathes that the noses were cylindrically ground after hardening. I can’t measure any appreciable runout.


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## Crosche (Mar 31, 2020)

RobinHood said:


> Hi Chad,
> 
> so you were basically turning an “egg shaped” part?
> 
> ...



The lathe came from a high school and you can tell that it's seen some crashes. I suspect that it maybe more than a single issue and that my problems could be both the spindle or spindle bearings and the chuck as well.
Is it possible for bearings to cause a high spot at a single, repeatable location on the spindle? The owner's manual says that the spindle bearings can be adjusted, but I am not sure if that's somewhere I want to go right now since I could possibly make things worse.
Any suggestions on how I can check the spindle for straightness? 
In answer to your question, yes, I believe that the part is slightly out of round.


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## Tom Kitta (Mar 31, 2020)

I would re-measure everything and make sure the part is indeed out of round and by how much. 

Are you sure its out of round not a taper? 

See here: https://www.practicalmachinist.com/vb/cnc-machining/parts-out-round-why-185163/


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## RobinHood (Mar 31, 2020)

What Tom said: re-measure your part as best as you can to make sure it is not just a taper. Also, if your chuck has worn (bell mouthed) jaws you may have the part move while you turn it - resulting it the observed problem. One way to see if it gets better would be to use the tailstock with a center to help support the part in the chuck - even if you have little stick out. If your out of round goes away, you need to regrind your chuck jaws. ( I had to do that on a cheap import chuck; it worked so well that I have since reground all 3Js - huge difference, well worth the effort ).



Crosche said:


> Any suggestions on how I can check the spindle for straightness?



As far as I know, the only accurate way to check for bends is to remove the spindle from the headstock. Use a surface plate and known good v-blocks to support the spindle on the bearing journals and a tenths indicator to check for runout while you slowly turn it in the v-blocks by hand.

You can use the same principle to measure for high spots (out of round) on your part that you made.


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## RobinHood (Mar 31, 2020)

Crosche said:


> Is it possible for bearings to cause a high spot at a single, repeatable location on the spindle?



I suppose it is possible. Does the spindle turn nice and freely when rotated by hand? Especially check FWD/REV and feel for any binding as the rollers reverse in their races.

Have you pulled the cover off? Check for proper oil lubrication to the front bearing by the brass wiper arm. How? Put the lathe in neutral gear not with the RH speed selector as usual, but rather with the LH lever by moving it between two gears. You can see if you are between the gears by checking the rear shaft. Select the HI range on the RH lever and turn the spindle by hand. You want to see the bull gear pick up oil and the scraper “peel” it off and it should then flow through the port into the front bearing housing. That should happen in both spindle directions. Some of the oil scrapers are not adjusted correctly and do not direct enough oil into the main bearing, causing it to overheat. This eventually causes the binding described above.

You can also check the rear spindle bearing. If it is bad, you could get a rough running spindle and possibly the runout you have observed.


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## Crosche (Mar 31, 2020)

So here is where I got to tonight. I put my indicator inside the spindle bore and didn't find any significant movement, although I don't have a tenths indicator so I am not sure that my measurement was relevant. The spindle seems to turn smoothly and I can't feel any binding. 





Next I put the indicator on the face of the spindle and rotated it. At the #1 cam lock position I consistently read 0.001" low, so now I am worried since I don't know how a bearing could influence the spindle in only one place. Although, I did place a screwdriver in the gap between the spindle and the headstock and pried VERY gently and the 0.001" would disappear. As the photos show, the spindle is pretty beefy, so it seems unlikely that I was deflecting the spindle? 








At this point I feel like I have to decide between the following:
1) try adjusting the main bearing
2) replace the main bearing
3) use my 4 jaw chuck exclusively 
4) try to skim cut the spindle mount face (yikes!)
5) replace the spindle (YIKES!!!) 

I did not try any tests with the 3 Jaw chuck since I do not trust it. The cam lock studs are worn and damage and until they are replaced I do not see value in performing tests with a suspect piece of equipment. Does this make sound logic or am I missing something? Tomorrow night I will take the cover off the headstock and see if anything seems amiss.







Any insight that you guys can share is appreciated because I am a bit out of my depth on this.

Thanks,

Chad


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## John Conroy (Apr 1, 2020)

I think you are measuring the run out in the wrong place if you are concerned about it affecting chuck runout.  If you look at the back of the chuck you will see that it registers on the outside taper of the spindle, not the inside where the pic shows the measurement being read. The face of the spindle does not have to be dead flat, the main interface between the chuck and spindle is the outside taper of the spindle.
Try measuring the OD of the spindle nose to see if any runout is in the same position as what you measured on the MT taper on the ID of the spindle.


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## Dabbler (Apr 1, 2020)

@John Conroy Are you meaning the face of the spindle adjacent to the spindle nose (the discoloured part in 20200331_171531.jpg, above.  It seems that a very light stoning of the entire face is in order. @Crosche notice the slightly raised area in 20200331_171629.jpg.  that would be the face seat, and is the face contact area.  A very light stoning of the seat on the chuck looks like it would do some good....

--- what I mean by 'light stoning", is to take a FLAT stone, and lightly pass it to feel for any burrs or imperfections.  You won't find them with a test indicator. I use the following stone for this, which has been straightened by hand on a diamond hone.


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## Crosche (Apr 1, 2020)

John Conroy said:


> I think you are measuring the run out in the wrong place if you are concerned about it affecting chuck runout.  If you look at the back of the chuck you will see that it registers on the outside taper of the spindle, not the inside where the pic shows the measurement being read. The face of the spindle does not have to be dead flat, the main interface between the chuck and spindle is the outside taper of the spindle.
> Try measuring the OD of the spindle nose to see if any runout is in the same position as what you measured on the MT taper on the ID of the spindle.



Hi John, 

The nose or cone of the spindle is what I measured initially. From my tests, the nose moved approximately 0.0005" and it seemed to always be in the same location. I will take another reading tonight and report my findings.


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## YotaBota (Apr 1, 2020)

I'm going to guess the lathe is new to you. Did you download the operators manual from the SM website? It will show you all the parts and pieces and an idea of how they go together. Have you changed the oil in the headstock?, coming from a school it could have been well or not maintained. It may sound unlikely but I've read were noises bumps and grinds disappear after a flushing and oil change.

Don't be afraid of taking the lathe apart, it will give you a better understanding of how things work and how to protect it form damage in the future. I bought a SM9" that was in a school and have had it apart a few times to change parts. You really have to watch for grub screws that are installed from the bottom, under a cover or just hidden from grime. The spindle is about the only thing I have come across that you may need to "persuade", having said that my experience is with my SM9", Logan 400 and an Atlas 618 so we really need someone with first hand experience with your lathe. I just did a quick google and there isn't much out so take it slow and keep asking when you get stuck.


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## RobinHood (Apr 1, 2020)

Hi Chad, good advice from both Johns.



Crosche said:


> The nose or cone of the spindle is what I measured initially. From my tests, the nose moved approximately 0.0005" and it seemed to always be in the same location



That could mean that the actual mounting flange (nose) of the spindle has taken a pretty big bump. The mashed up cam lock stud (circled in red) could mean that the chuck came off the spindle at one time pretty violently.






This is the area Dabbler was suggesting to stone off any burrs. Also check the mating surface inside your chuck body and lightly stone it. You can also run a stone on the face of the spindle to knock off any burrs.






When you attach the chuck, be sure to confirm the cam indicator line ends up between the 3 to 6 o’clock position as shown. If it is outside, you need to adjust the studs in the chuck(s).






1) There should be no spindle endplay; the 1 thou you measured is too much. Adjust the front bearing as per the SM manual - it gives the correct pre-load on the Timken bearing.

2) Replacing the main bearing could be a challenge as on later model lathes they shrunk fit the bull gear bushing onto the spindle. No way to get it off other than cut it. (Heat won’t do it, I tried - at least the amount I was willing to put in did nothing; perhaps I was too chicken?). Then you can get the Timkens off. Bearings are in the $1200 range - 6 months lead time from Timken.

3) If the spindle is not bent between the bearings, using any chuck or even collets in the spindle should give you round parts.

4) Not unless you know for sure where the problem lies. Then I would use a Tool Post Grinder. Or take the spindle out and have it cylindrically reground.

5) New spindle - going to be tough to find one and probably lots of $$$s.


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## Dabbler (Apr 1, 2020)

+1 to wwhat @RobinHood said.  Are you in Calgary?  I could bring my Mit tenths and my Noga arm and we could remeasure everything.... [Respecting social distancing, of course]


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## Crosche (Apr 1, 2020)

RobinHood said:


> Hi Chad, good advice from both Johns.
> 
> 
> 
> ...




Yes, I am quite worried that the spindle has taken "quite" a bump and the 0.001" endplay from light pressure with a screwdriver is concerning too. I would think that the side load from cutting would be greater than the force I generated. 
My manual doesn't have the torque settings or procedure to do it; however the SM 1120 & 1340 manual gives the torque value, so I will use that as a starting point. 
For peace of mind I got a quote for the main bearing assembly; 2 V-cones and a cup; and was quoted $256 + GST. I may purchase the new bearing, but will have to see what I am dealing with once I take the cover off of the headstock tonight.


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## Tom Kitta (Apr 1, 2020)

At least price for the whole assembly is not high and you can buy it!


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## Crosche (Apr 1, 2020)

Dabbler said:


> +1 to wwhat @RobinHood said.  Are you in Calgary?  I could bring my Mit tenths and my Noga arm and we could remeasure everything.... [Respecting social distancing, of course]



Yes, I am in Calgary. I live in Huntington Hills area and I would appreciate the help and a second set of eyes. I believe my shop is large enough to meet the current social distancing requirements and can supply your preferred choice of beverage. Please let me know what your availability is like and we can set a time up.

Regards, 

Chad


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## RobinHood (Apr 1, 2020)

Crosche said:


> For peace of mind I got a quote for the main bearing assembly; 2 V-cones and a cup; and was quoted $256 + GST.



Are you sure the quote was for ABEC 7 or better high precision bearings? If it is, perhaps you could share the vendor with the group, thanks.


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## Crosche (Apr 1, 2020)

RobinHood said:


> Are you sure the quote was for ABEC 7 or better high precision bearings? If it is, perhaps you could share the vendor with the group, thanks.



The quote was for the following as specified by my owner's manual:

Timken type T.D.O. Assy. No. A-4968
Consisting of:
Qty 2 x cone, 387A
Qty 1 x cup, 384ED


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## RobinHood (Apr 1, 2020)

Sorry Chad, but I am pretty sure that was a quote for standard precision C3 clearance cones and cup like they would use in an automotive or general industrial application.

You need #3 precision (or better) for your lathe:










$1534.21 + GST and they are available to order only; when I checked ~ 2 years ago, it was about 5-6 months...

You might get a discount if you can put it through a company name.


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## Brent H (Apr 1, 2020)

Hello.  

Do not forget the back bearing in these lathes.   It is a a normal roller hearing and typically wears out before the front conical ones.  The adjusting nut for the forward conical bearing preload rides on the centre of this bearing.  Could be that This bearing is worn and messing up the preload by the. 0.001”.   Could cause a few other issues...:


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## Crosche (Apr 1, 2020)

RobinHood said:


> Sorry Chad, but I am pretty sure that was a quote for standard precision C3 clearance cones and cup like they would use in an automotive or general industrial application.
> 
> You need #3 precision (or better) for your lathe:
> 
> ...



It's possible that the vendor messed up the quote or I wasn't specific enough; however I did give them the part numbers directly from the manual. Regardless, I think I will pay them a visit and see what the deal is.


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## Tom Kitta (Apr 2, 2020)

I have some Timken bearings - l have cups and actual bearing - they are quite large. I think through they are automotive precision. 
https://cad.timken.com/item/all-pro...d-single-with-flange-imperial/68462-68712-b-2
and
https://cad.timken.com/item/tapered...-roller-bearings---single-cups---imperial/672

I think they are way to large for you.

In case you want specifics size go to eBay - you can find stuff there that is *much cheaper* then from supplier.

You are very lucky you can get bearings for your lathe that are still in production. However ABEC 3 bearings that are not widely available will cost indeed a lot of money - even if still made. 

Sizes in 4inch bore and 6" outside are for under 200 USD on eBay - but I think it is automotive grade ABEC 1 or something like that. Check your size.

Before you buy make sure your bearings are indeed dead - it is not exactly "quick procedure" in many lathes to change bearings. Also pre load frequently is a mystery and determined by how much stuff moves.


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## Dabbler (Apr 2, 2020)

So @Crosche and I spent a while doing all kinds of measurements...  Yes his spindle is bent, but not irretrievably.  the inner taper MT#4, was about a half tenth out, which is fine for lathe that old and used...  the *taper *of the D1-4 is out about .002 and the outer flange consistently clocks at .005 out in axial measurement.  The face seat of the d1-4 is so rough, that a half thou indicator couldn't read it.

None of this is fatal, and a tool post grinder can clean up the axial runout.  The radial runout is still just fine.

His new Shars chuck seats on the area near the taper, so we adjusted it and got it fitting quite nicely.

For the sad news, his 3 jaw chuck, a very high quality Pratt chuck BTW, will probably have to be replaced.  as the taper seat is badly chowdered.


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## Tom O (Apr 3, 2020)

Try transmission supply on 58th i got timkin bearings for my Clausing there it wasn't a bad price either!


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## John Conroy (Apr 3, 2020)

Thanks for bringing us up to date Dabbler. It was very nice of you to help out a fellow hobbiest. Are you guys going to grind the face of the spindle? That would make a great video for those of us who have never seen it done.


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## Crosche (Apr 3, 2020)

Firstly, Dabbler, you have my sincerest gratitude for taking the time to inspect my lathe and educate me at the same time; especially in light of the current pandemic situation. My shop, my equipment and my skills; as modest as they may be; are at your service and in your debt. 

As far as the lathe is concerned, I am not sure whether to be happy that it's not the bearings that are the problem or not, but I will have to correct the problem at hand and I see post grinding the D1-4 spindle nose in my near future. I will try to get video footage or at least good pictures of the set-up and process when it happens. 

With respect to the bearings, @RobinHood and others who may be interested. I contacted Standard Modern for a quote for the main bearings for my lathe and specifically asked for the bearings that they use and I was quoted $300 for the assembly, so I can only assume that the bearings they use are C-2's and the same as quoted by TPL. In my research regarding the bearings I did stumble across C-3 bearings in stock for $770 USD ($1100 CDN) which is slightly more palatable than $1500 CDN and 6 month lead time provided by Motion Canada. https://3bgsupply.com/bearings/roller-bearing/387a-3-timken

Lastly, I want to thank all of you who offered up advice, observations and encouragement. I was very concerned that I made a poor purchase and was going to be stuck with a lemon who's cost to repair would far outweigh it's actual value but with your help I have a clear path forward to grind / polish this "turd" into something I can be proud of.


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## RobinHood (Apr 3, 2020)

Hi Chad,

Glad to hear that you were able to identify/verify your spindle runout measurements with the help of Dabbler.

I owe you an apology for suggesting that your lathe needs #3 precision bearings; evidently that seems to be one of the changes / upgrades from a 11” series 2000 Utilathe, like yours, to a 1120.

Did you adjust the endplay of your spindle?

Have you had a chance to turn a part using your Shars chuck to see if you still get a high spot?

One thing that still puzzles me a bit: how come the spindle bore has almost 0 TIR and the other reference surfaces have 2 to 5 thou? Its almost as if there was a problem during the grinding of the spindle nose from factory.
My reason for this observation: if the spindle is indeed bent ahead of the main bearing, the bore should also show a significant TIR - like 1 to 1.5 thou - because the wall surface you are measuring is a good 3/4” out from the spindle center line. So the further from center you go, the more the runout (as confirmed by measurement on the nose and flange face).
Just thinking out loud... maybe I am missing something.


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## PeterT (Apr 3, 2020)

Was just typing when Rudy posted. That's what I was wondering too.

Maybe my understanding of D-spindles is flawed. I thought that tooling had to fit simultaneously to the taper cone (red) and the back face (green). The orange has clearance to the adapter plate so doesn't really factor. So if you grind either 'fit' faces, I'm not sure how it can mate the adapter/chuck properly. ie. if its eccentric right now (as opposed to cleaning up a raised burr superimposed on a otherwise good circle) then by the time you have ground the cone smaller, it would now have resultant radial clearance relative to the female plate 'socket' side, no?

I had an issue on a wonky face plate where the taper angle was correct but it was shallow to the extent it wasn't mating the back face. That caused the plate to be sucked in at varying angles when the camlock pins were tightened. Hence my understanding that the back face being simultaneously flush was critical too.


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## Crosche (Apr 3, 2020)

RobinHood said:


> Hi Chad,
> 
> Glad to hear that you were able to identify/verify your spindle runout measurements with the help of Dabbler.
> 
> ...



No apology required. You taught me something about bearing tolerances that I didn't know, so thank you. Hopefully the link I posted for the slightly less expensive bearings proves useful. 

I am curious too about the vast differences in wear between the bore of the spindle and the spindle nose/chuck mount. Dabbler offered a few possibilities to explain the anomaly. Perhaps the chuck mount is press fit onto the shaft and was mounted crooked. Or the mount is cast iron and relaxed in an unusual way. 
My thought is that it may have occurred when a student slammed a loose chuck into the carriage and distorted the spindle nose. Any thoughts on this?

I haven't turned anything in the new chuck yet. Since it is a 4 jaw chuck will it yield any useful information because I should be able to adjust out most of the error, is this correct?


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## Tom Kitta (Apr 3, 2020)

As someone whom made now two back plates for D1-3 the proper fit is on the red surface and touch the green surface. They yellow surface is not touched as the back-plate / chuck usually has lots of air space for swarf or dirt. 

The trick is in 1 setting angle correctly and 2 in making the size of the taper very precise. My primitive method is to bore to within about two or three thou and then finish the rest with sand paper & constant re-check against spindle. 

Given that setup I have no clue as to how anyone wants to grind red surface on the spindle - size here is very precise. Any change and chuck on it will be loose. Unless you also grind precisely green surface and calculate precisely how much you need. I.e. you need to grind green first and then extend red taper. If lots is removed you may need to shorten yellow.


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## PeterT (Apr 3, 2020)

The spindle nose must be dealt with first before introducing the chuck / back plate marriage into the equation. Sounds like you guys have made some good headway but a few more points to ponder. If the chuck taper is egged or abused or otherwise not fitting, that creates a new secondary issue. Hopefully sketch shows what I was referring to. The cones are not mating axially for whatever reason so even a perfect spindle cannot make a part held in chuck run correctly. The simplest check is to borrow a known 'good' matching backplate fixture or chuck & check that way. Even so you would be measuring relative to a gripped dowel pin or similar so jaw/collet grip enters the picture. But it might help you diagnose if you have a spindle issue or chuck issue or both. For example of someone gripped a pin with his chuck & says it dials in within 0.001" no matter how I bolt it on my D1 spindle and you bolt that same undisturbed chuck/dowel in your spindle and get the same, then we are hinting the spindle may be ok & your chuck is defective. But if your numbers are vary significantly then the spindle is the focus point. Its not scientific but it might be easiest at this stage.


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## Crosche (Apr 3, 2020)

PeterT said:


> Was just typing when Rudy posted. That's what I was wondering too.
> 
> Maybe my understanding of D-spindles is flawed. I thought that tooling had to fit simultaneously to the taper cone (red) and the back face (green). The orange has clearance to the adapter plate so doesn't really factor. So if you grind either 'fit' faces, I'm not sure how it can mate the adapter/chuck properly. ie. if its eccentric right now (as opposed to cleaning up a raised burr superimposed on a otherwise good circle) then by the time you have ground the cone smaller, it would now have resultant radial clearance relative to the female plate 'socket' side, no?
> 
> I had an issue on a wonky face plate where the taper angle was correct but it was shallow to the extent it wasn't mating the back face. That caused the plate to be sucked in at varying angles when the camlock pins were tightened. Hence my understanding that the back face being simultaneously flush was critical too.




Hi Peter,

My takeaway from last night and subsequent tests is that the mount has a high spot of 0.005" that is repeatable in the same location. I see your point about the taper not fitting correctly if the plate is ground. Dabbler said that grinding the taper on the cone is a tricky bit of business.
So, I wonder if I will have to order a new spindle nose from Standard Modern and press fit it if that's possible? Or will I be stuck having to shim my chuck to take the slop out? Or remove the spindle completely and send it out to a shop to have it professionally ground?


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## Crosche (Apr 3, 2020)

PeterT said:


> The spindle nose must be dealt with first before introducing the chuck / back plate marriage into the equation. Sounds like you guys have made some good headway but a few more points to ponder. If the chuck taper is egged or abused or otherwise not fitting, that creates a new secondary issue. Hopefully sketch shows what I was referring to. The cones are not mating axially for whatever reason so even a perfect spindle cannot make a part held in chuck run correctly. The simplest check is to borrow a known 'good' matching backplate fixture or chuck & check that way. Even so now you are holding a reference pin & jaw grip enters the picture. But it might help you diagnose if you have a spindle issue or chuck issue or both.



Are you suggesting that the spindle nose taper needs to be ground first or should I buy a new 3 jaw chuck before getting too carried away?


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## PeterT (Apr 3, 2020)

Your question is slightly higher than my pay grade (hence me wondering out loud if I understand spindles in general). There are more qualified guys on the forum. But reducing an egged spindle cone by grinding sounds like one of those 'I cut it 3 times and its still to short' syndrome.

The starting point for rotating tool interchangeability is spindle nose dimensions & tolerances have to be within spec. You could (maybe) bastardize a chuck to fit but now what - every time you want to change to a different chuck you have no reliable reference because now the 'standard' female socket on back plate will always be slightly larger than the re-ground spindle cone. The camlocks just provide axial pull, not axial or radial alignment.


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## RobinHood (Apr 3, 2020)

Here is a chart with the acceptable tolerances for D1 spindles. Yes, the mounted item has to seat on the nose and back up against the face at the same time.


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## PeterT (Apr 3, 2020)

Crosche said:


> Hi Peter, My takeaway from last night and subsequent tests is that the mount has a high spot of 0.005" that is repeatable in the same location.?



Yup, and I'm suggesting there could be more to the story. Defect on the left is a somewhat isolated raised bump but the other 99% of section remains circular. For example when you hit a surface with a chisel, there is a resultant negative indentation but typically also a positive raised surface on either side just based on material flow. For example resultant from a deep scratch or better yet an embedded chip. Anyways this type of defect could be stoned off & you are back in business because you are back to mating on the good 99%. So if the DTI needle jumped within a few rotation degrees it would indicate this type of distortion.

But if its more like right sketch where the circle is actually eccentric, that's a different issue. DTI test should show a gradual climb to the max runout. Grinding this shape to the mean minimum circle will result in a smaller circle. Now, was it this way to begin with & you actually have some excess meat to grind to a dimensional spec spindle?. Rudy is one step ahead by providing the spec dimensions. But OTOH if it was circular & good to begin with and now its distorted, that's a more difficult problem because the re-grind would have to be smaller than spec.


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## Crosche (Apr 3, 2020)

According to the chart, I am screwed. The tolerances given on the chart are so tight that any corrective measures that I need to take would exceed them several times over and the D1-4 spindle nose is integral to the spindle so it cannot be replaced.


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## Crosche (Apr 3, 2020)

PeterT said:


> Yup, and I'm suggesting there could be more to the story. Defect on the left is a somewhat isolated raised bump but the other 99% of section remains circular. For example when you hit a surface with a chisel, there is a resultant negative indentation but typically also a positive raised surface on either side just based on material flow. For example resultant from a deep scratch or better yet an embedded chip. Anyways this type of defect could be stoned off & you are back in business. So if the DTI needle jumped within a few rotation degrees it would indicate this type of distortion.
> 
> But if its more like right sketch where the circle is eccentric, that's a different issue. DTI should show a gradual climb to the max runout. Grinding this shape to the mean minimum circle will result in a smaller circle. Now, was it this way to begin with & you actually have some excess meat to grind to a dimensional spec spindle?. Rudy is one step ahead by providing the spec dimensions. But OTOH if it was circular & good to begin with and now its distorted, that's a more difficult problem.



I would describe the bump on the spindle taper to be like the first diagram, a rather pronounced change, but the face of the chuck mounting surface to be like the second diagram.


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## PeterT (Apr 3, 2020)

Is there any visible difference in the spindle where the DTI change is, like axial scratches or gouge? Or does it look smooth everywhere & the DTI just reads this bump?

Another advantage of mating a known 'good' taper fixture is you can blue the spindle with felt pen, gingerly mate the good fixture & see what kind of shiny pattern you get. This gets a bit tricky because it could be rubbing on both sides of the raised dimension. But a shallow stripe or more isolated interference rub off would be good news over a broader area.


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## Crosche (Apr 3, 2020)

PeterT said:


> Is there any visible difference in the spindle where the DTI change is, like axial scratches or gouge? Or does it look smooth everywhere & the DTI just reads this bump?
> 
> Another advantage of mating a known 'good' taper fixture is you can blue the spindle with felt pen, gingerly mate the good fixture & see what kind of shiny pattern you get. This gets a bit tricky because it could be rubbing on both sides of the raised dimension. But a shallow stripe or more isolated interference rub off would be good news over a broader area.



The taper and face of the spindle feel smooth to the touch, no significant scratches, dents or dings.


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## RobinHood (Apr 3, 2020)

I do not know how they make these spindles - from solid or in pieces. The 3 spindles I have had out from my 3 different lathes did not seem to be made from components, rather from solid. Hence my questioning of how can a flange bend without the tube it is part of not distorting? Those are pretty serious junks of steel requiring serious forces to bend. I saw that you have a lantern post - presumably original - it would move out of the way long before any appreciable damage would be done to the spindle. OTOH, that stud on that chuck does really look beat up...

I have a number of known good D1-4 items we could try on your spindle. My problem is this raging pandemic. I am around high risk people and should not take any chances. I would be out in a flash to help you out.

I know you want to make things right and get your lathe in decent shape, but if it were me, replacing the spindle would be my last resort. I would want to make absolutely sure that there is not any other way.

Even if as PeterT just posted, and you have measured, there is a high spot on the spindle nose, your parts should still turn out cylindrical if the spindle runs true in its bearings.

I would mount the 4J and turn a decent size of metal, say 2” diameter by 5” long with about 3” stickout. Turn off about 25 - 50 thou and measure the cylinder. I would not be surprised if that works out. It would indicate that your 3J needs work. I am suspecting it is bell mouthed and the work piece actually moves in the jaws.


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## PeterT (Apr 3, 2020)

Getting back to possibly what Rudy & I were wondering if this was the scenario. If the spindle section outboard of the bearing got bent in an unfortunate encounter, then the the DTI test should show a max runout spot which you have. But the confirmation would be to mark that spot, reset the DTI 180-deg to different position, say underside, rotate & the same spot should repeat. But if I understood correct you detected a bump on the outer cone but not on inner surface? This is aspect I wasn't clear on


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## Crosche (Apr 3, 2020)

RobinHood said:


> I do not know how they make these spindles - from solid or in pieces. The 3 spindles I have had out from my 3 different lathes did not seem to be made from components, rather from solid. Hence my questioning of how can a flange bend without the tube it is part of not distorting? Those are pretty serious junks of steel requiring serious forces to bend. I saw that you have a lantern post - presumably original - it would move out of the way long before any appreciable damage would be done to the spindle. OTOH, that stud on that chuck does really look beat up...
> 
> I have a number of known good D1-4 items we could try on your spindle. My problem is this raging pandemic. I am around high risk people and should not take any chances. I would be out in a flash to help you out.
> 
> ...




I am going to chuck up a piece of material in the 4J and see what the results are; there is no doubt that the 3J was badly abused and probably destined to become a rotary welding fixture. 

For chuckles I sent a quote request to Standard Modern for a new spindle, but I am all but certain that the price will make the C-3 bearings look like a bargain.  

Where are you working with the high risk patients? I am an instrument technician with AHS down at South Health Campus.


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## RobinHood (Apr 3, 2020)

Crosche said:


> Where are you working with the high risk patients? I am an instrument technician with AHS down at South Health Campus



Actually it is family member with an immune deficiency. Other than getting food twice and dropping off a tool I made for my brother so he can work on a homogenizer, I have not left my property for 3 weeks.


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## Crosche (Apr 3, 2020)

PeterT said:


> Getting back to possibly what Rudy & I were wondering if this was the scenario. If the spindle section outboard of the bearing got bent in an unfortunate encounter, then the the DTI test should show a max runout spot which you have. But the confirmation would be to mark that spot, reset the DTI 180-deg to different position, say underside, rotate & the same spot should repeat. But if I understood correct you detected a bump on the outer cone but not on inner surface? This is aspect I wasn't clear on




You are correct. There appears to be a small bump on the cone but not in the bore. I will check to see if the bump on the cone corresponds to the bump on the flat mounting surface on the nose. What I can't seem to wrap my head around is HOW anyone could possibly cause the spindle nose to deflect so much as to distort it? You would have to stress the metal beyond it's plastic limit and there just doesn't seem like there is enough clearance between the back of the spindle nose and the body of the headstock to permit that kind of deformation, but hey I didn't think that the corona virus would shut down the planet either, so what do I know? 
OTOH, I don't understand how a bearing would cause a repeatable deflection at the exact same spot on the spindle nose and face? Dabbler spun the shaft several times and the bearing appeared to be fine. However, maybe it's worth pulling the spindle out and checking the bearings? At this point I am not sure what I have to loose.


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## Tom Kitta (Apr 3, 2020)

Yeah, you may want to disassemble the whole spindle and then put it back together also inspecting the bearings and how are they placed in.

About two years ago on my rather beaten lathe I had it run in my garage not well leveled - it was supposed to move to my new garage so I did not "take care" of the beaten up beast. I was making a small part at its top speed of around 1500 rpm (plus 20% or so for 10Hz extra) so around 1800 rpm machining a longer thin shaft (maybe 10 inches so not outrageous). I heard the spindle make whine noises... I stopped the lathe - the spindle was making a noise and grunt and single spot during turning. I think I fried the bearings. Turns out getting large Gamet (UK made) bearings is next to impossible.

My dad helped me dissemble the spindle. I removed and cleaned the bearings. Little cylinders were not scarred and there was just a little smudge on the cup. Re-assembled and this time leveled the lathe. Works fine - at least the bearings. The nose still has some stoned damage on it and bed looks like it went through both world wars.


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## RobinHood (Apr 3, 2020)

Looking into headstock and (possibly) removing the spindle, etc, and giving it a thorough cleaning can not hurt. As Brent mentioned above, check that SKF 6009-2RS rear bearing. Excellent point on inspecting the main bearing Tom. It takes next to nothing to cause things to go out of tolerance. Gives you the chance to set the endplay as well on re-assembly. You have nothing to loose.


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## Crosche (Apr 3, 2020)

Tom Kitta said:


> Yeah, you may want to disassemble the whole spindle and then put it back together also inspecting the bearings and how are they placed in.
> 
> About two years ago on my rather beaten lathe I had it run in my garage not well leveled - it was supposed to move to my new garage so I did not "take care" of the beaten up beast. I was making a small part at its top speed of around 1500 rpm (plus 20% or so for 10Hz extra) so around 1800 rpm machining a longer thin shaft (maybe 10 inches so not outrageous). I heard the spindle make whine noises... I stopped the lathe - the spindle was making a noise and grunt and single spot during turning. I think I fried the bearings. Turns out getting large Gamet (UK made) bearings is next to impossible.
> 
> My dad helped me dissemble the spindle. I removed and cleaned the bearings. Little cylinders were not scarred and there was just a little smudge on the cup. Re-assembled and this time leveled the lathe. Works fine - at least the bearings. The nose still has some stoned damage on it and bed looks like it went through both world wars.




Believing that this lathe was going to be my perfect one true love, I broke down and purchased a precision level and made sure that the ways are level.


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## Crosche (Apr 3, 2020)

RobinHood said:


> Looking into headstock and (possibly) removing the spindle, etc, and giving it a thorough cleaning can not hurt. As Brent mentioned above, check that SKF 6009-2RS rear bearing. Excellent point on inspecting the main bearing Tom. It takes next to nothing to cause things to go out of tolerance. Gives you the chance to set the endplay as well on re-assembly. You have nothing to loose.



I just purchased some Prussian blue to map out how the 4J chuck is fitting. Also, I called a friend who believes that he has a 3J D1-4 chuck that I could borrow for some test pieces. After that, tearing the lathe apart seems like the next course of action.


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## Brent H (Apr 3, 2020)

@Crosche - stay with it. - -  there is not enough “shaft” to bend on the end. -  

Could be a matter of some clean up and a few new D1-4 components.  

if you need links to manuals and drawings @RobinHood or myself and some others can supply. It is not difficult to pop out the shaft and even turn it between centres on a larger lathe the see what is the issue.   Check that bugger back bearing - see if your adjustment collar is tight - I can set you up with the Timkin conical bearing adjustment if you need.


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## Dabbler (Apr 3, 2020)

wow - I'm sorry I've been offline most of the day...  I took a lot of measurements and for me there is no mystery.  A chuck was crashed causing a .003 thou deflection int the D1-4 mating outer ring.  That bend caused a .0015 deflection on the opposite side, causing a .005 difference in the whole rotation. (don't worry about the ,0005 difference - long story.

On the centre cone:  It is not an ovoid or radially displaced.  it is deflected almost .002.  since the face of the seat is very rough, no reasonable measurements could be taken to verify, but I'm 90% sure.

The tiny deflection on the MT4 bore of the spindle is simple geometry.  Assume  you make a bend in the tube of the spindle, measuring .003 axial at the flange over 3" from the centre line. by using sin law, the angle of deflection is a little under .0525 of a degree. guessing that the bend, at worst case, is 2"inboard from the measuring point, you get 2 tenths deflection, which is what it was reading, more or less.

Even though I was using a tenths indicator, I wasn't calibrating, and conditions weren't optimal.  So all these things should be taken +/- a little - I'm comfortable that the measurements back up the 'bent spindle' theory.

--------------------------------------

Now for the mitigation.  The lathe can be used as-is, and will do 'okay' work, if things are done in a single setup.  For re-registration and to get the best out of the lathe, some toolpost grinding is in order.  I would leave the MT4 as is, as 2 tenths is just fine.

The back flange has to be trued to a maximum axial runout of .0005 wich will require just over .003 grinding  No you do NOT need to try to make it totally flat. if you have 2/3 of the backplate perpendicular to the centre line, it will work just fine.

Now to the centre cone.  Since a properly fitting chuck won't 'reach' the back plate any more, and since it still has a 'bend' artifact, it will have to be ground as well.  you'd be surprised to find that by the calcs, it will need less than a thou of grinding, possibly in the order of .00075  again, 2/3 seating rule.

This won't make a 'perfect' lathe, but chucks will seat properly, and work will be good and repeatable.  taking any more will introduce the possiblility of ruining the D1-4, I should stress that none of this should be done in one go. and final fitting will still require honing and/or polishing with diamond grit - but the spindle is salvageable with work.

Now if SM offers a spindle at, say 500 bucks, it's a no-brainer.  The lathe will be like new again.  I seriously suspect it will be about $1700 instead, hence my mitigation plan.


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## Brent H (Apr 3, 2020)

Hey Dabbler, is it worth pulling the shaft assembly out and checking it all on a true lathe between centres?


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## Crosche (Apr 3, 2020)

Brent H said:


> @Crosche - stay with it. - -  there is not enough “shaft” to bend on the end. -
> 
> Could be a matter of some clean up and a few new D1-4 components.
> 
> if you need links to manuals and drawings @RobinHood or myself and some others can supply. It is not difficult to pop out the shaft and even turn it between centres on a larger lathe the see what is the issue.   Check that bugger back bearing - see if your adjustment collar is tight - I can set you up with the Timkin conical bearing adjustment if you need.



Thanks


Dabbler said:


> wow - I'm sorry I've been offline most of the day...  I took a lot of measurements and for me there is no mystery.  A chuck was crashed causing a .003 thou deflection int the D1-4 mating outer ring.  That bend caused a .0015 deflection on the opposite side, causing a .005 difference in the whole rotation. (don't worry about the ,0005 difference - long story.
> 
> On the centre cone:  It is not an ovoid or radially displaced.  it is deflected almost .002.  since the face of the seat is very rough, no reasonable measurements could be taken to verify, but I'm 90% sure.
> 
> ...





Dabbler said:


> wow - I'm sorry I've been offline most of the day...  I took a lot of measurements and for me there is no mystery.  A chuck was crashed causing a .003 thou deflection int the D1-4 mating outer ring.  That bend caused a .0015 deflection on the opposite side, causing a .005 difference in the whole rotation. (don't worry about the ,0005 difference - long story.
> 
> On the centre cone:  It is not an ovoid or radially displaced.  it is deflected almost .002.  since the face of the seat is very rough, no reasonable measurements could be taken to verify, but I'm 90% sure.
> 
> ...




Wow John! I couldn't articulate any of our findings nearly as accurately; not in a million years.

Working backwards from your post. I contacted Standard Modern and they do not have the part number in their system and could not locate a drawing; although that's not a complete surprise since they are working from home. Regardless, getting a new spindle seems like a long shot.

As for your advice last night on tool post grinding the spindle nose, I purchased some plans for a tool post grinder and have been studying DIY grinders on YouTube & Pintrest in preparation of what seems inevitable because it was not my intention to buy a so-so lathe, but rather a good machine able to perform well.

With respect to disassembling the headstock, it's not a task that I relish, but I can't help wonder that if some idiot crashed the lathe so hard as to affect the spindle that the bearings escaped completely unharmed. I am no expert in this matter by any means and if you don't think that energy put into disassembling the headstock is wasted energy then I will focus my efforts on more useful tasks. 

I think that I will be able to borrow a 3J chuck from a friend, so I should be able to conduct some further tests. Additionally, I procured some Prussian blue to try and map the contact area of the chuck.


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## Brent H (Apr 3, 2020)

http://vintagemachinery.org/pubs/detail.aspx?id=6935


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## Dabbler (Apr 3, 2020)

Thanks Brent!  the drawings were very helpful!

We'll try a few things when you get your loaned 3J in, @Crosche...  It will help pinpoint the error better.  (I suppoe we should have taken you 4J jaws out and do a few more things!


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## Tom Kitta (Apr 3, 2020)

Unless spindle is very weak in the machine a crash - even hard one seems to do little to it - https://www.practicalmachinist.com/vb/general/curious-what-heck-can-bend-lathe-spindle-162942/

Here is a long read about another D1-4 having issues:
https://www.practicalmachinist.com/...rested-any-approaches-git-er-straight-279738/

On page two they have videos and the spindle clearly is out in both X and Y direction.

Verdict is that problem is not bent spindle but loose bearings that either need replacement or adjustment. 

Apparently if spindle is well designed the only way to kill it is place a shaft in the spindle chuck, make sure your lathe is attached to the floor with some bolts and then lift by the bar using a fork lift.  I don't know how well you machine is designed through - apparently some home grade machines are so weak you can bend the spindle by looking at it.


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## PeterT (Apr 3, 2020)

Crosche> ..._the taper and face of the spindle *feel smooth* to the touch, no significant scratches, dents or dings._
Dabbler> ...i_t is deflected almost .002. since the face of the seat is *very rough*, no reasonable measurements could be taken to verify, but I'm 90% sure_

LOL. are we all talking about the same thing here? - the conical spindle surface?


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## PeterT (Apr 3, 2020)

_Additionally, I procured some Prussian blue to try and map the contact area of the chuck._

Give it a go but I've actually had better luck with a Sharpie felt pen mark in this particular application. Prussian is kind of a oil based creamy substance, it kind of needs some displacement of the 2 surfaces to show shiny. You might have enough discrepancy gap that either will stand out. As long as they give the same message use either/or but don't do anything drastic just based on Prussian, To remove Sharpie (or Dykem btw) methyl hydrate works great.


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## PeterT (Apr 3, 2020)

This discussion motivated me to measured my Taiwan 14x40 lathe spindle tonight. With a 10-ths DTI I measured 0.0003-0.0004 'oblong-ish' runout on the OD regardless of where I place the DTI ball along the chord. I marked the max deviation line and I have exactly the same thing on the inner MT5 taper. I'm pretty sue this is what I measured on the lathe when new-ish, or more probably when I finally acquired a tenths reading DTI.

Interesting thing, with DTI ball on the surface & lathe under the lowest rpm I get the same min/max needle reading of say 0.0004" but the whole deviation center drifts back & forth maybe 1-2 tenths. I'm not sure if this is vibration, or bearings warming up, or bearing influence...?

Another interesting thing is the rotating spindle back face surface is dead nuts, like not even an honest tenth deviation out. OK, So I guess if the spindle cone was a bit off, but basically tight enough that its making contact, that would allow for some minor amount of off-axis displacement. But if the vertical faces are true & coincident the axis will be parallel to one another & there is a lot more contact area on that surface.

I know this isn't helping the Standard Modern mystery but just providing a data point. Mine isn't perfect either but I'm going to guess this is maybe about right for reasonably used lathe? Did you guys measure the back face as well?


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## Crosche (Apr 4, 2020)

Brent H said:


> @Crosche - stay with it. - -  there is not enough “shaft” to bend on the end. -
> 
> Could be a matter of some clean up and a few new D1-4 components.
> 
> if you need links to manuals and drawings @RobinHood or myself and some others can supply. It is not difficult to pop out the shaft and even turn it between centres on a larger lathe the see what is the issue.   Check that bugger back bearing - see if your adjustment collar is tight - I can set you up with the Timkin conical bearing adjustment if you need.




Thanks very much for the info Brent, I will check the back bearing as you suggest and may even replace it considering it is not very expensive to do so. With respect to the conical bearing adjustment ,are you referring to a tool, a work procedure or preload specifications?
That being said, @RobinHood , you were as precise as the bearings that are used in the machine. According the the drawings provided by @Brent H , they are C-3 bearings which makes sense - precision bearings = precision lathe. I do not know why Standard Modern quoted me the C-2 bearings, but I will certainly be following up with them to ask why. Thank you again for imparting that knowledge upon me.


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## Crosche (Apr 4, 2020)

Dabbler said:


> Thanks Brent!  the drawings were very helpful!
> 
> We'll try a few things when you get your loaned 3J in, @Crosche...  It will help pinpoint the error better.  (I suppoe we should have taken you 4J jaws out and do a few more things!



@Dabbler I will let you know when I get the 3J and we can strategize from there.


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## Crosche (Apr 4, 2020)

PeterT said:


> Crosche> ..._the taper and face of the spindle *feel smooth* to the touch, no significant scratches, dents or dings._
> Dabbler> ...i_t is deflected almost .002. since the face of the seat is *very rough*, no reasonable measurements could be taken to verify, but I'm 90% sure_
> 
> LOL. are we all talking about the same thing here? - the conical spindle surface?


 

Hi Peter,

Maybe surface finish is relative like beauty or more likely it was late and I wasn't picking up everything @Dabbler was laying down. For clarity and my own piece of mind I took some detailed pictures of the spindle nose and the back of the 3J. In comparison to your spindle nose or a tenths indicator, mine is less than perfect, but in comparison to the chuck the spindle nose is a work of art.


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## RobinHood (Apr 4, 2020)

Hi Chad,

Looking at the pictures, things do not appear too bad - but that means nothing.

When you have time, I would recommend that you rebuild your 3J. Take *everything* apart. Clean thoroughly, deburr the backplate ( you can use wet/dry 800-1000 grit paper on a surface plate if you have; otherwise a piece of flat glass will work too; use WD40 or kerosene as wetting agent). Deburr everything else too - you can use files and sanding sticks on the non-critical surfaces. Reassemble with light oil or grease. Chucks need regular (tear down) maintenance to operate properly. Cleaning just the outside only goes so far...

Looks like you may have some rust on your spindle nose - at least that is what the discolouration looks like. Use a rag soaked in Evaporust (not affiliated) and dab the spindle nose for about 10-15 min to keep the area wet. You will see if the stain (rust?) starts to rub off. Keep going using some white paper towels until there is no more dirt coming off the spindle. Dry off. Lightly oil it (WD40 mixed with a light oil works well) as the spindle will flash rust immediately after cleaning. Stone all the surfaces; if you have no stone, you can glue some fine grit wet/dry paper to a very flat piece of metal or hardwood. You will feel any burrs. You can then polish everything up with paper towel soaked in WD40.

Here is a link to Timken Taper Roller Bearings Catalogue - the front section (first 60 pages or so) has some “light engineering” reading...
http://catalog.timken.com/Tapered-Roller-Bearing-Catalog/C/

Based on the SM 11” Series 2000 Utilathe Manual (link here... http://www.standardmodernlathes.com/docs/manuals/standard-modern-utilathe-11-13-inch-manual.pdf) they in fact *do not specifically call* for #3 precision bearings. So maybe on that model lathe, they did not use them yet and the quote you got is in fact correct. You would have to pull the spindle to see what type bearing you have.

Keep working methodically, one step at a time, starting with the easy stuff first. You will get there.


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## kevin.decelles (Apr 4, 2020)

@RobinHood Can you post a link to a picture/reference to the type of “stone” you would use? I see lots of references to stoning machinery but don’t fully understand the type of stones being referenced


Sent from my iPad using Tapatalk


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## RobinHood (Apr 4, 2020)

Here you go Kevin. An example of a source - there are many more.
https://www.gessweincanada.com/category-s/11299.htm

Basically google “Arkansas Stone” or “India Stone”

If you want the ultimate in precision, you can surface grind them; Stephan Gotteswinter and Robin Renzetti have videos (there are others of course)

Here is my Japanese water stone: red side is 1000 grit, yellow is 6000. I keep it in a Tupperware container full of water so it is ready to use right away.






I need to surface grind it to make it perfectly flat again. Project #156...


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## Dabbler (Apr 4, 2020)

@kevin.decelles I use a small aluminum oxide triangular hard die stone for much of my working on machine tools, and  a small 1" X 4" 3000/10,000 combo stone for touching up tapers and flat surfaces like the back of chucks, etc.

The 1 X4 was bought on amazon.com for about 6 bucks.  the die  stone is a 1/2 X 4  and cost me 30 bucks in the 80s.  I think bigger than 1X4 is unwieldy for working everything but mill tables.  

@RobinHood  The discolouration  if the spindle is mostly contaminated grease.  I did not observe any rust on the chucks or spindle.  The 3J taper has been worn out by chips and misuse.  It is VERY rough.  When mounted, the 3J just falls off when the cams are released, instead of needing a little thump from a soft hammer.  The Shars 4J chuck needs an authoritative thump to remove it.  Another reason I think the taper on the lathe is in good shape.


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## RobinHood (Apr 4, 2020)

Thanks for clarifying @Dabbler, appreciate it. So maybe not worth playing around with the 3J at this time then...


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## PeterT (Apr 4, 2020)

Did you guys have a DTI running along the vertical face? (red arrow). How did that measure?

Also, kind of secondary but did you have a dial on the outer boss OD (orange arrow). I'm curious if runs different or maybe the same as where the max runout bump is on spindle cone.

Your chuck back plate looks a bit chowdered up. If it has protrusions like bumps or rust or embedded chips it might have fitting problems of its own even on an otherwise perfect spindle. That's why I was saying, for now focus on the spindle  so you can divide the problem. As others have said, it wouldn't hurt to lightly stone your your spindle area, just don't go crazy on it. Paint it with a Sharpie marker first, then the stoning will show you what surfaces are coming off. I would do the back face (red arrow surface), again very lightly. Look for raised burrs around the pin holes where it may have hit the edge while mounting or whatever. If you ended up getting that Dykem you could paint the lathe back face, mount the chuck I see what kind of impression you get. I'm not sure that a direct perpendicular mate like that will transfer (it kind of works best when slid laterally which you cant do) but no real harm in trying. It might show something. If you end up borrowing a good known chuck, repeat & see what you get. 

Also you could remove the pins in the chuck back & use the Dymen to check for flatness. A glass plat will work well enough for now.


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## PeterT (Apr 4, 2020)

Dabbler said:


> @kevin.decelles The Shars 4J chuck needs an authoritative thump to remove it.  Another reason I think the taper on the lathe is in good shape.


That's a very good sign. Now it could be from oblonged spindle cone effect too, but put it this way - if the chuck goes on & off similarly to another known 'good' chuck then fingers are pointing to the rough chuck vs. the spindle.


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## Dabbler (Apr 4, 2020)

@PeterT The 3J is seriously toast.  I'd love to restore it, it is a nice Pratt chuck, but years of abuse have destroyed it.

Yes the vertical face is the 'axial' runout, which has a highest-to lowest difference of 5 thousandths. As I explained above, if the spindle was bent nearly 3 thousandths, it would give you an axial runout of 5 thou.

Yes as I explained above, every surface was stoned with a  precision stone.  there were no burrs or High spots.

The 'outer boss' is not a ground surface: so indicating it will not tell anything.  What you want to measure is the Radial runout, which is is about 2 tenths. That is why it is measured inside the spindle on the MT4 surface. 

I hope this clears it up.


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## PeterT (Apr 4, 2020)

_Yes the vertical face is the 'axial' runout, which has a highest-to lowest difference of 5 thousandths._
So you are saying a DTI on this face is moving in & out 0.005" as the spindle rotates?

_The 'outer boss' is not a ground surface: so indicating it will not tell anything._
Ya that's why I said secondary. I don't really know but would assume they would grind this boss at same time as face & cone. I forgot to check mine but will now. Anyways what I was wondering out loud is if it was deviated at same clock position as the face & cone, that would maybe further indicate a shaft deviation bend as opposed to a localized blemish


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## Dabbler (Apr 4, 2020)

PeterT said:


> So you are saying a DTI on this face is moving in & out 0.005" as the spindle rotates?



There is ,005 axial movement total from the lowest point to the highest point, on that face. not .005 in and .005 out - that would be a total runout of .010.



PeterT said:


> grind this boss



I assumed you were talking about the clearance behind the taper, which was my best interpretation of your yellow lines. so by that comment I now think you are talking about the _taper._  The taper is ground is very smooth and in good condition, but it deviates from the centre of rotation with a total runout of .002. 

- I was confused by your term 'boss' which I have never heard in conjunction with a spindle - it is also sometimes referred to as the 'nose'...


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## Brent H (Apr 5, 2020)

Looking at the pics the D1-4 is in great condition - mine looks like crap compared - LOL.  I would pull the shaft and check it for runout on a bigger lathe.  Might even find a few bits of steel or bad bearings or mal adjustments causing the issue.  

I ended up chucking the chuck my lathe came with as the jaws were NFG after years of someone spinning things out.


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## Dabbler (Apr 5, 2020)

@Brent H I'm sorry to hear about your chuck/lathe.

The runout issues on @Crosche lathe are fixable, and the rest of the lathe is  pretty good overall.


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## PeterT (Apr 5, 2020)

Dabbler said:


> I was confused by your term 'boss' which I have never heard in conjunction with a spindle - it is also sometimes referred to as the 'nose'...



Sorry for confusion, I'm probably not using the right terminology. Here is my cave man drawing. Kind of hard to convey in 3d perspective. The curve is the DTI ball trace path when rotating the spindle. The double head arrow is example orientation of DTI  deflection measurement. Green = 'boss' or outer ring thingy, Orange = vertical face, Red = external nose taper cone (like a D1-4 spec), Grey = internal taper cone (like an MT5 spec)


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## RobinHood (Apr 5, 2020)

Maybe time to summarize?

OP had problem making cylindrical parts using a 3J chuck.
Measurements were taken on spindle. Runout was detected inside the bore [white arc/arrow - in picture above] (low Total Indicator Runout - TIR); on the D1 nose taper [red arc/arrow] (more TIR); on the face [yellow arc/arrow] (even more TIR); and presumed most TIR on the circumference [green arc/arrow] (not measured because it is not a reference surface).
Critical surfaces were stoned to eliminate existing burrs.
Inside of headstock was inspected - nothing out of the ordinary.
Spindle turns smoothly in its bearings.
Evidence of previous owner(s) crashing the lathe is visible (chuck, compound, etc.)
3J the OP used is a poor fit to the D1 mount (it falls off when cams are released).
Good quality 4J is available and a decent 3J is being borrowed.

Conclusion: 

Spindle most probably is slightly bent ahead of the main bearing.
Poor fitting / worn out original 3J most likely  allowed the work to move around as it was being turned - resulting in the out of round part.

Good News:

The lathe is fully usable with good chucks (both 3J & 4J).
It will turn round parts - so ongoing / future projects  could be completed.

Long Term:

Purchase a good 3J. Always mount it in the same orientation to the spindle (should be standard shop practice anyway). Mark that orientation. Properly grind the jaws in situ - *that now takes out the runout of the spindle*; do to both inside and outside jaws.
With lots of time and very careful work, it might be possible to restore the original 3J: first get it to fit properly to the D1 mount, then grind the jaws as above.
Remove spindle for full blown bench inspection.
Regrind as last resort - any mistakes will ruin it.

Anecdotally: the Rohm manual specifically tells you to grind any replacement jaws you purchase from them - even with their very high German standards of manufacture, one matches the jaws to the body to eliminate runout.


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## Crosche (Apr 5, 2020)

Serious thanks to all of you for your recommendations and brainstorming. Once we put this nasty covid-19 business behind us I'd love to have you guys over for some beverages, snacks and maybe hit some hot metal.


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## Tom Kitta (Apr 6, 2020)

I did red only surface on both of my lathes. One is D1-3 and one is D1-6. The first one has taper in excellent shape. Spindle bearings are advertised as "Gamet Micron precision" and TIR is not detectable down to 1 micron. I.e. 1/2 tenth indicator does not indicate any runout.

On my beaten destroyed D1-6 the indicator jumps around on all sort of dings but total runout is around 2 tenths - maybe 3. Bearings are advertised as "Gamet Micro precision". Note that this lathe was beaten, wet and left out to dry. 

I have a video if I fix it I post it.


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## Crosche (Apr 8, 2020)

Out of interest I checked on the price of a new spindle for the lathe and was quoted $3300 CDN; good thing I was sitting down when I opened the quote!


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## Tom Kitta (Apr 8, 2020)

Here is the video of the runout on both of my lathes.


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## Crosche (Apr 8, 2020)

Tom Kitta said:


> Here is the video of the runout on both of my lathes.




Thanks for posting that Tom. The Colchester is in splendid condition, but the poor Empire has definitely seen better days.


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## Tom Kitta (Apr 8, 2020)

Crosche said:


> Thanks for posting that Tom. The Colchester is in splendid condition, but the poor Empire has definitely seen better days.



I scare pp with the condition of the front of the ways. When almost locked at front the saddle goes only half way through. Despite so much wear and general abuse especially small parts come up not too bad - actually you can get some good results. With some tweaking you can even get longer parts OK.

Main difference between worn out machine and in great shape machine is that with worn out machine you have to account for the wear and things may not come out bang on the very first time - this is a bit frustrating at times. With tight machine you can concentrate on just the part - with worn out you have to deal with the machine far more. You need less skill / time to make a good part on a tight machine. This is for parts where tolerances that are "tight" matter - for 90% of home shop stuff tolerances are loose. For example if you are cutting off some metal to make space for a weld - you don't care - you use lathe b/c its faster then a grinder. Or when making a handle for another machine - its not critical it is .75 inch. Or my recent project making an adapter for a die (so smaller die 2" can fit in 2.5" handle) - my actual result worries me I made it too exact - the 2.5" handle has at least .020 slop - I made it around .010 smaller - even total beater without any effort should be able to do it.

Hence why some pp make their own lathe on YouTube and claim they can make good parts - for many things they are right.


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## PeterT (Apr 8, 2020)

Good video Tom. I'm going to have to get myself set up on YouTube one day. 

On your good lathe, is that original spindle assembly or did you do some bearing work yourself?
I was going to ask how your back face (lateral in & out run out) compared but I'll bet a beer its dead nuts.

Goes to show, don't judge a machine by chipped or new paint! LOL


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