# Spindle nose re-grind?



## phaxtris (Aug 21, 2022)

Story goes...a while back I tossed a center in the spindle...and there was a noticeable "wobble" in the center...so I threw an indicator on the outside and inside tapers, .004" runout!

Yea massive, but not noticable, and doesn't seem to affect accuracy much with the chuck mounted, someone must have turned the backing plate with the runout... whattever

I pulled the spindle this weekend to see if it were bearings or a bent spindle, I've attached a pic of my setup to check the spindle, it may not be .0001" accurate but it is enough to see that the internal and external tapers are definitely running out

The lathe can turn accurate enough parts for my use as is, but it bothers me that i 1 have to turn the face place to have it run true, and 2 I would have to turn the center every time I wanted to use the face plate

So the question is...has anyone ground a spindle nose and Morse taper with a tool rest grinder in situ? Or should I just live with it... skim the face plate and turn a center in pos when I want to run faceplate/center ?


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## Susquatch (Aug 21, 2022)

Can you get a new spindle?

I don't follow why you need to faceoff the face plate each time. Can't it be faced once and then indexed on the spindle so it always goes on the way it came off? 

Can you setup a larger female taper right on the face plate instead of using the spindle MT? 

Can you make a spindle center adapter that runs true to the spindle and use that instead of the spindle MT?


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## phaxtris (Aug 21, 2022)

Susquatch said:


> Can you get a new spindle?
> 
> I don't follow why you need to faceoff the face plate each time. Can't it be faced once and then indexed on the spindle so it always goes on the way it came off?
> 
> ...



i would only need to skim the faceplate once, it has a keyway to register location....this is the reason you cant see the runout with the chucks, they mount to backing plates that are turned while mounted and register in a key way, it would be the center that would need to be cut every time as there would be no way to index it ( if i was using the faceplate with the center)

if i just want to run a center i just do the cut a center in the chuck trick and dog off one of the jaws, no big deal there

the only way im getting a new spindle would probably involve a trip to brazil and learning to speak Portuguese, so thats out

the easiest thing i think would be to skim the face plate and cut the center every time, but that brings up the question, do they make non hardened morse taper centers ? i cant seem to find one


just kinda looking for input on what other people might do....im very tempted to just roll with it how it is, i never even knew it was out until that one day i slammed a center in the spindle for no good reason


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## YYCHM (Aug 21, 2022)

Make your own MT centers and true them up with every use.  Do you have a taper attachment?

I guess you could try applying a MT reamer to the current spindle and see if things improve......


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## phaxtris (Aug 21, 2022)

YYCHM said:


> Make your own MT centers and true them up with every use.  Do you have a taper attachment?
> 
> I guess you could try applying a MT reamer to the current spindle and see if things improve......



i thought about an mt reamer, i dont think it would be hard enough to cut the spindle, and it would probabaly just follow the current taper, i dont know that it would remove the runout

i dont have a taper attachment, i think the compound might have enough travel to make an acceptable taper, i also havent actually tried to cut the center i have.....maybe i should give that a go, what do i have to lose really


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## PeterT (Aug 21, 2022)

A little out of my league here but I really wonder how accurate the spindle tube itself is, which is how you have it supported. If it is slightly banana, then the spindle nose will appear out relative to the rollers. But I think the important runout is the spindle nose once bearing is fixed in the headstock. Did you already establish in the lathe that you have spindle nose runout & that's why the spindle is out now?
Assuming the bearing is still in good shape, is it possible to support on the housing or bearing OD & see if you get the same numbers?


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## phaxtris (Aug 21, 2022)

PeterT said:


> A little out of my league here but I really wonder how accurate the spindle tube itself is, which is how you have it supported. If it is slightly banana, then the spindle nose will appear out relative to the rollers. But I think the important runout is the spindle nose once bearing is fixed in the headstock. Did you already establish in the lathe that you have spindle nose runout & that's why the spindle is out now?
> Assuming the bearing is still in good shape, is it possible to support on the housing or bearing OD & see if you get the same numbers?



Yes, it runs out when installed, I just checked it out of the machine like that as a sanity check, I don't take those numbers as the actual runout numbers, just a confirmation that it wasn't bad bearings


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## Susquatch (Aug 22, 2022)

phaxtris said:


> just kinda looking for input on what other people might do....im very tempted to just roll with it how it is, i never even knew it was out until that one day i slammed a center in the spindle for no good reason



Well that answers my next question which was gunna be "Why do you need a center?"

Ive had a lathe for 40 plus years. I've never used a center in the spindle even once. I don't even have one. My newer lathe has an mt5 taper so that's a honking big taper for a center.

If I need a center, I make one that is chucked not put in the taper, and it's usually just a small piece of bar cut with my compound at 30 degrees to make a 60 degree taper. Since it is cut in a chuck as it will be used, it's always perfectly concentric to my spindle.

Given what you just said, I'd stop worrying about it and just roll with it too.

For that rare time you might actually need one, just get a big bar that is machineable, cut your spindle taper into it using your chuck, flip it, and then make a new 60 each time you use it. An index mark with a punch, or carbide scribe, or even a sharpie might work pretty well too. I frequently use that trick so I can avoid parting off and wasting stock on a bar that is machined full length. It's surprising how well a simple index mark will repeat.


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## Mcgyver (Aug 22, 2022)

I've ground spindle tapers before for collet mounts but don't there is much point for centres imo.  With the three jaw chuck mounted, chuck a piece of steel, turn a 60 degree point on it with the compound....I think most machinists do it that way as it eliminates a source of error.  The dog is driven by a jaw.  The stub in the 3 jaw will be as true to the lathe's axis as the bearings are.


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## 6.5 Fan (Aug 22, 2022)

I agree with what Sasquatch said, for the very few times you need a center, machine one in the three jaw.


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## Susquatch (Aug 22, 2022)

Mcgyver said:


> I've ground spindle tapers before for collet mounts but don't there is much point for centres imo.  With the three jaw chuck mounted, chuck a piece of steel, turn a 60 degree point on it with the compound....I think most machinists do it that way as it eliminates a source of error.  The dog is driven by a jaw.  The stub in the 3 jaw will be as true to the lathe's axis as the bearings are.



@phaxtris - This is what I recommended above too, but @Mcgyver said it better than I did. 

Its also nice to know that this is what most machinists do as I am mostly self taught.


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## Mcgyver (Aug 22, 2022)

Susquatch said:


> @phaxtris - This is what I recommended above too, but @Mcgyver said it better than I did.
> 
> Its also nice to know that this is what most machinists do as I am mostly self taught.


lol, me too.  I don't mean to sound as if puttng on airs, I'm not a machinist and I can't present a comprehensive and statistically accurate polling around my claim of "most" , but over the years I believe I've heard more guys known to be career machinists saying its how they do so than say they don't do it that way.

I'm sure you'll agree, that once you get onto it, you never think mounting a centre in the spindle.


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## Degen (Aug 22, 2022)

Susquatch said:


> Well that answers my next question which was gunna be "Why do you need a center?"
> 
> Ive had a lathe for 40 plus years. I've never used a center in the spindle even once. I don't even have one. My newer lathe has an mt5 taper so that's a honking big taper for a center.
> 
> ...


Depends on how you are doing your work and how you can adjust your work in a lathe.

I've used centers in the spindle on several occasions over 30 years mostly when my spindle is to small for the work to get the best results and there the answer is "turn between centers son"!  The second is turning with inducing external stresses from the chuck on the part during turning (this is a whole other discussion).

With modern smaller lathes spindle dimensions have increased so much so that centers are becoming less used, but having the option is great (but time consuming) option.

I bought my new lathe for one reason only, not to use centers as the solution and save about 15-30 mins per piece of prep and setup time, now its just a chuck it and cut it operation.

Now as to your issue of taper correctness,  start with your lathe setup first before making alterations this drastic though important if required.  There is a whole (heated and very informative ) thread about this. Second test the offending device in the spindle in several orientations to confirm if its the spindle or the device.

Finally if its intrusive enough cut and/or grind away, this is truly how you fix it (there are done good Youtube videos on this).

Remember, check, check, check and check again pause and check again before you cut/grind as worst case could cause you more grief and problems.


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## phaxtris (Aug 22, 2022)

So it sounds like everyone is on the same page, leave it, cut a center in pos when required

That's the way I was leaning, better than chance making it worse


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## historicalarms (Aug 22, 2022)

phaxtris said:


> i thought about an mt reamer, i dont think it would be hard enough to cut the spindle, and it would probabaly just follow the current taper, i dont know that it would remove the runout
> 
> i dont have a taper attachment, i think the compound might have enough travel to make an acceptable taper, i also havent actually tried to cut the center i have.....maybe i should give that a go, what do i have to lose really


  Im with YYC on a simple new taper pocket manuf would be the most expedient "permanent fix" but i also agree withphaxtris that introducind a stationary reamer into a turning spindle will just produce another wonky pocket....my sugestion would be to take the spindle to another shop that has the capability of turning the reamer into a stationary spindle (line up for square & straight would be crucial).


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## mickeyf (Aug 22, 2022)

The one case that comes to mind in which you  might want to put a center directly into the spindle rather than in a chuck is if you have a work piece that is so long that you need that extra few inches of length that the chuck consumes. Rare, but can happen. I wouldn't go out of my way to worry about that until it actually came up, which might be "never".


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## Susquatch (Aug 22, 2022)

mickeyf said:


> The one case that comes to mind in which you  might want to put a center directly into the spindle rather than in a chuck is if you have a work piece that is so long that you need that extra few inches of length that the chuck consumes. Rare, but can happen. I wouldn't go out of my way to worry about that until it actually came up, which might be "never".



True, but then what do you attach the drive dog to? LOL! 

I'm in the camp that says that @phaxtris will never use it.... LOL! 

In my mind, the only time that spindle taper will get used will be for a spindle mounted collet holder or a test bar. The latter is probably a moot case now that we know how wonderful those test bars are.....


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## phaxtris (Aug 22, 2022)

Susquatch said:


> True, but then what do you attach the drive dog to? LOL!
> 
> I'm in the camp that says that @phaxtris will never use it.... LOL!
> 
> In my mind, the only time that spindle taper will get used will be for a spindle mounted collet holder or a test bar. The latter is probably a moot case now that we know how wonderful those test bars are.....



You would drive the dog off the faceplate, it mounts flush to the spindle nose, err flush with the spindle nose


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## Susquatch (Aug 22, 2022)

phaxtris said:


> You would drive the dog off the faceplate, it mounts flush to the spindle nose, err flush with the spindle nose



I meant without the faceplate.... 

We already talked about the faceplate method before so I assumed this is without that and hence my question....


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## phaxtris (Aug 22, 2022)

Susquatch said:


> I meant without the faceplate....
> 
> We already talked about the faceplate method before so I assumed this is without that and hence my question....



Without the faceplate method loses you the 6-8" for the chuck, that's the point of the center in the spindle...center in the spindle dog driven from the faceplate


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## PeterT (Aug 22, 2022)

phaxtris said:


> Story goes...a while back I tossed a center in the spindle...and there was a noticeable "wobble" in the center...so I threw an indicator on the outside and inside tapers, .004" runout!



OK now I'm kind of confused. I assumed from your first post & pic showing DTI on outside surface of spindle nose, that it indicates 0.004" runout relative to bearing/shaft. I assumed it was a type-L  (not that it really matters) & so the inside taper was going along for the ride & have similar runout. Are you saying the DTI reading between outside & inside surface is different to each other on the same test setup & that will adversely affect turning between centers with a center arbor in place?


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## phaxtris (Aug 22, 2022)

PeterT said:


> OK now I'm kind of confused. I assumed from your first post & pic showing DTI on outside surface of spindle nose, that it indicates 0.004" runout relative to bearing/shaft. I assumed it was a type-L  (not that it really matters) & so the inside taper was going along for the ride & have similar runout. Are you saying the DTI reading between outside & inside surface is different to each other on the same test setup & that will adversely affect turning between centers with a center arbor in place?



You are correct, the inside taper is going along for the ride, same runout as far as I can tell as the outside taper

One can just true up the faceplate, and then a soft  center would need to be made and trued up each time (although like mentioned a whiteness mark on the center and the spindle nose would make it much less)


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## PeterT (Aug 22, 2022)

Trueing up the faceplate & turning a new center in-situ kind of works for centered turning (only). But assuming I understand the L spindle correctly, isn't the bigger issue that the other 99% of the time, whenever you mount a chuck or anything referencing off the spindle OD, it's going to have corresponding (actually exaggerated) runout for stock holding?


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## Tom Kitta (Aug 22, 2022)

Susquatch said:


> Well that answers my next question which was gunna be "Why do you need a center?"
> 
> Ive had a lathe for 40 plus years. I've never used a center in the spindle even once. I don't even have one. My newer lathe has an mt5 taper so that's a honking big taper for a center.
> 
> ...



At least you have standard MT. My British machine is MT4.5 Yep, 4 and a half. There is a big jump from 4 to 5 and smaller machines would have hard time getting to MT5. But MT4 is small and too small for collet systems... so MT4.5 was born. Good luck finding it for sale - you got to roll your own... BUT even that is not easy as pp do not agree as to what dimensions 4.5 has - many say its same as MT4 taper just bigger....

I actually never missed not having MT4.5. To really "feel it" I would need a special case where part is so long that I cannot just put in a center inside of 4 jaw chuck! With 4 Jaw (or collet chuck) I can re-use the center not cut it every time. Also my ER40 collet chuck looses maybe 3". 

So realistically its not an issue 99.9% of the time. And for rare times it would be an issue I have a bigger lathe...


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## phaxtris (Aug 22, 2022)

PeterT said:


> Trueing up the faceplate & turning a new center in-situ kind of works for centered turning (only). But assuming I understand the L spindle correctly, isn't the bigger issue that the other 99% of the time, whenever you mount a chuck or anything referencing off the spindle OD, it's going to have corresponding (actually exaggerated) runout for stock holding?



All the chucks for L ( that I have at least) are mounted to a backing plate that is turned in situ, and indexed with a keyway on the spindle nose, so the only runout induced from the spindle taper is whattever slight slop is in the keyway allowing the backing plate to mount not in the *exact* same location every time. I'm sure there is at least .001 or more of clearance there, Wich by the time you figure the rotation on the nose that allows, probabaly give some amount of runout (to a 3j Wich runs out anyways, or a 4j Wich you have to dial in)


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## phaxtris (Aug 22, 2022)

Tom Kitta said:


> At least you have standard MT. My British machine is MT4.5 Yep, 4 and a half. There is a big jump from 4 to 5 and smaller machines would have hard time getting to MT5. But MT4 is small and too small for collet systems... so MT4.5 was born. Good luck finding it for sale - you got to roll your own... BUT even that is not easy as pp do not agree as to what dimensions 4.5 has - many say its same as MT4 taper just bigger....
> 
> I actually never missed not having MT4.5. To really "feel it" I would need a special case where part is so long that I cannot just put in a center inside of 4 jaw chuck! With 4 Jaw (or collet chuck) I can re-use the center not cut it every time. Also my ER40 collet chuck looses maybe 3".
> 
> So realistically its not an issue 99.9% of the time. And for rare times it would be an issue I have a bigger lathe...


 So what your saying is, come to your house when I need something to long for a center in the chuck right


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## Susquatch (Aug 22, 2022)

phaxtris said:


> Without the faceplate method loses you the 6-8" for the chuck, that's the point of the center in the spindle...center in the spindle dog driven from the faceplate



OK, so let's just drop this part of the conversation. I was only trying to point out that you need to drive the dog with something. I thought somebody said you just needed the centre to get the most length. But a faceplate loses some of that. So I was asking how you would drive the part without the faceplate.

But all that just got everyone confused. You are not planning to use the centre anyway.

It's all good. Just forget about the spindle center. Make one for your 3-jaw chuck and start makin stuff!


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## phaxtris (Aug 22, 2022)

Susquatch said:


> OK, so let's just drop this part of the conversation. I was only trying to point out that you need to drive the dog with something. I thought somebody said you just needed the centre to get the most length. But a faceplate loses some of that. So I was asking how you would drive the part without the faceplate.
> 
> But all that just got everyone confused. You are not planning to use the centre anyway.
> 
> It's all good. Just forget about the spindle center. Make one for your 3-jaw chuck and start makin stuff!



Yea there is a lot of going back and forth, and confusion, but I don't lose any length with the faceplate, do you lose length on a camlock with a faceplate ? I'm guessing that's what you have ?


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## Susquatch (Aug 22, 2022)

phaxtris said:


> Yea there is a lot of going back and forth, and confusion, but I don't lose any length with the faceplate, do you lose length on a camlock with a faceplate ? I'm guessing that's what you have ?



Yes, I do. And yes I do! LOL! 

But it is a zero problem for me. I have a 40" bed.

Let me put that a bit differently. One of my chucks (one I made myself) has an integrated set of three spiders. It is over a foot long! 

I don't have a machine length problem at all for anything I do.


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## Mcgyver (Aug 22, 2022)

Tom Kitta said:


> At least you have standard MT. My British machine is MT4.5 Yep, 4 and a half.



I had a SM once that had the 4.5.  Ideal for collets as you say.  It was big enough to fit the most common collet size, 5Cs.  With the factory adapter (very well made and hardened) it was like a really big watchmakers lathe.  So nice, I miss that lathe.  I've now got a Swiss Habbeger  with a (somewhat rare?) 5C spindle nose, not parting with that one!

I have seen dimensions for 4.5 published in MT tables, but no idea if most/all/few manufactures followed it.


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## Susquatch (Aug 22, 2022)

Mcgyver said:


> I've now got a Swiss Habbeger with a (somewhat rare?) 5C spindle nose, not parting with that one!



While not nearly as nice as having an integral 5C spindle nose like yours, I have a bison 5C Collet chuck for my D1-5 Camlock Spindle. *I LOVE IT. *It is the chuck that lives on my lathe the vast majority of time. 

It's easy to see why you love yours.


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## Mcgyver (Aug 22, 2022)

PeterT said:


> rueing up the faceplate & turning a new center in-situ kind of works for centered turning



kind of works?  imo its the preferred approach to setting up to turn between centres.  It eliminates the  sources of error at the headstock centre and creates a centre perfectly aligned to the lathes bearings, i.e. zero runout.  (concentric taper bore, dings or bumps or debris in headstock/adapter mount, eccentricity in the taper adapter, eccentricity in the centre, dings or bumps or debris in between centre/adapter).

Not sure how the faceplate entered into?   How do you hold the centre you turning in situ, and what does the faceplate to?  Below is a typical setup I'd use - this roughing out a new spindle shaft for a small mill on my DSG.  Quick, easy and imo the most accurate set up.


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## Mcgyver (Aug 22, 2022)

Susquatch said:


> While not nearly as nice as having an integral 5C spindle nose like yours, I have a bison 5C Collet chuck for my D1-5 Camlock Spindle. *I LOVE IT. *It is the chuck that lives on my lathe the vast majority of time.
> 
> It's easy to see why you love yours.



Direct mounting dude....next level . I bought that lathe last year for well under 2k with a full (by 64ths) set of 5C hardinge collets....and not like it was a secret or a hot deal. I do know the seller, but it sat on kjiji for weeks and nobody called him. I've got a Schaublin 102 i'm going to sell, W20, so smaller, but it is the same idea. direct mount and has a few schaublin collets.   Busy Bee on speed dial and the Swiss lathes don't sell lol.  Probably thats not 100% fair as they are not threading, but it does amaze me that it sat on kijiji and wasn't snapped up instantly.

I'd posted a bunch of the Habegger photos here, toward the end....There is also a video of showing not a tenth runout with a collet....Busy Bee's on speed dial and the Swiss lathes don't sell lol.









						Schucks, now the shop is even more crowded shop - collets and a Habegger
					

you are welcome and apolgies for the the verbosity...been thinking about it so long it refreshing to share it with someone who might benefit from some of it




					canadianhobbymetalworkers.com
				




 .


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## PeterT (Aug 22, 2022)

Mcgyver said:


> kind of works?  imo its the preferred approach to setting up to turn between centres.  It eliminates the  sources of error at the headstock centre and creates a centre perfectly aligned to the lathes bearings, i.e. zero runout.  (concentric taper bore, dings or bumps or debris in headstock/adapter mount, eccentricity in the taper adapter, eccentricity in the centre, dings or bumps or debris in between centre/adapter).
> 
> Not sure how the faceplate entered into?   How do you hold the centre you turning in situ, and what does the faceplate to?  Below is a typical setup I'd use - this roughing out a new spindle shaft for a small mill on my DSG.  Quick, easy and imo the most accurate set up.



@Mcgyver I'm not disputing that turning a sacrificial center in-situ will make it run true relative to the rotation axis. I'm reconfirming what I think OP is collectively saying:
- the spindle nose OD has 0.004" runout as measured by DTI while rotating in the lathe environment (that's a problem)
- the spindle socket ID has similar runout when measured at the same time (so I'm inferring the spindle nose as a unit is somehow off axis, relative to the bearing axis)
- the spindle nose runout measures similarly with spindle removed from lathe & supported on roller test apparatus (not quite sure this distinguished where the source of distortion is occurring but interesting nonetheless)

So then the conversation went to how to accurately support stock between centers. And I'm agreeing with you, about the only viable option is to insert a sacrificial center & turn it in-situ. The mention of face plate comes from OP, not me, post #1
_So the question is...has anyone ground a spindle nose and Morse taper with a tool rest grinder in situ? Or should I just live with it... *skim the face plate* and turn a center in pos when I want to run faceplate/center?_

And, presuming the face plate mounts to the spindle nose OD like a chuck, skimming it doesn't do a lot of good because presumably its only purpose is to offer a slot for the lathe dog?

And what I'm now asking is: ok now you have a method to turn between centers. As most people expressed, that turning mode probably only represents a small percentage of lathe work holding where say a chuck would be mounted on the spindle nose & thus go along for the ride with spindle nose run-out.

If I'm still missing the picture, I'll come back in a few days & maybe the fog will have lifted. (It may well be confined to my brain LOL).


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## Susquatch (Aug 22, 2022)

PeterT said:


> @Mcgyver I'm not disputing that turning a sacrificial center in-situ will make it run true relative to the rotation axis. I'm reconfirming what I think OP is collectively saying:
> - the spindle nose OD has 0.004" runout as measured by DTI while rotating in the lathe environment (that's a problem)
> - the spindle socket ID has similar runout when measured at the same time (so I'm inferring the spindle nose as a unit is somehow off axis, relative to the bearing axis)
> - the spindle nose runout measures similarly with spindle removed from lathe & supported on roller test apparatus (not quite sure this distinguished where the source of distortion is occurring but interesting nonetheless)
> ...



Nah, both you guys (@Mcgyver & @PeterT ) did what I did. The thread jumped around a bit with all kinds of input without reference to source. Poop happens.

I just gave up because I was only making it worse. We are ALL on the same page and so is the OP (@phaxtris ) now. 

It's all good.


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## Mcgyver (Aug 23, 2022)

Peter thanks for the full account, I was slow on the uptake but am with you now.


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## Dabbler (Aug 23, 2022)

@phaxtris Here's a solution for what it is worth.  make a MT bar out of soft material that will fit your wonky spindle -- wait for it -- and then 'turn in place' your 60 degree centre, just as *if* it was held in a 3 jaw chuck.  You will gain the precious 4  inches or so.  the cost is that every time you remove it, you will have to recut it.  Run your dog in the faceplate as usual.

I reread the thread several times, but I didn't get that this was the agreed solution.  If it is, chalk it up to my advancing years.


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## Susquatch (Aug 23, 2022)

Dabbler said:


> @phaxtris Here's a solution for what it is worth.  make a MT bar out of soft material that will fit your wonky spindle -- wait for it -- and then 'turn in place' your 60 degree centre, just as *if* it was held in a 3 jaw chuck.  You will gain the precious 4  inches or so.  the cost is that every time you remove it, you will have to recut it.  Run your dog in the faceplate as usual.
> 
> I reread the thread several times, but I didn't get that this was the agreed solution.  If it is, chalk it up to my advancing years.



I believe your solution is indeed new.  And its a good one too.  Your advanced years brain is still working great!

That said, @phaxtris has indicated that he has no immediate need for the extra 4 inches.  (Lucky guy)  It was more of a "what if I ever did need" question. As such, using the chuck is just plain easier to make the sacrificial center because there is no need to make the MT taper to go with it.


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## RobinHood (Aug 23, 2022)

Here is how Standard Modern made sure there is maximum distance between centers available on their lathes:

They use a special “dog plate” to drive the dog. Looks like a face plate, but it is not. The center is held in a precision ground (and hardened) spindle bore adapter.






This is where the OPs problem would lie since there is a good amount of runout inside his spindle bore.

The solution as suggested by @Dabbler using a “soft“, machinable center (which needs turning before each use) will give max distance between centres. If max distance is not crucial, just do as others have suggested and true up a piece of steel held in either the 3J or 4J and use a chuck jaw as a drive point.


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## jcdammeyer (Aug 23, 2022)

So I have no opinion on how anyone else should do this.  Perhaps it's my Gingery Lathe building background but I like turning stuff between centers.  And way way back when I bought my lathe one of the people on the South Bend group was making the special SB Taper to MT3 taper adapters.  So I bought one.  My only complaint is that the MT3 center doesn't recess deep enough.





And it takes very little time to spin off the the current chuck or remove the 5C collet holder and insert the Center and spin on the drive plate.

After that it's just a matter of turning whatever needs to be done between centers.  In this case to do the pulleys the arbor was swapped end for end a few times.  





When done, tap out the insert and un-thread the drive plate and replace with whatever.  
I really like this approach.  And one day I'll turn a new MT3 center that is recessed closer to the drive plate.  One day...


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