Standard Modern 11" Series 2000 Lathe Spindle Issue

Crosche

Super User
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.
 

Crosche

Super User
Crosche> ...the taper and face of the spindle feel smooth to the touch, no significant scratches, dents or dings.
Dabbler> ...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

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

Ultra Member
Premium Member
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.
 

kevin.decelles

Jack of all trades -- Master of none
Premium Member
@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
 

RobinHood

Ultra Member
Premium Member
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.

C3A4262F-EA11-4B69-86AE-795FDAE55D53.jpeg

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

ersatz engineer
@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.
 

PeterT

Ultra Member
Premium Member
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

Ultra Member
Premium Member
@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.
 

Dabbler

ersatz engineer
@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.
 

PeterT

Ultra Member
Premium Member
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

ersatz engineer
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.

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

Ultra Member
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.
 

PeterT

Ultra Member
Premium Member
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

Ultra Member
Premium Member
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.
 

Crosche

Super User
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.
 

Tom Kitta

Ultra Member
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.
 

Crosche

Super User
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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