Spindle for Raglan lathe

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Spindle for Raglan lathe

This topic has 17 replies, 12 voices, and was last updated 7 January 2011 at 12:31 by Paul Smitherman.

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2 November 2010 at 19:08 #58012
Ian MILLARD
Participant
@ianmillard76204
Hi

Does anybody know where i can get a spindle remanufactured for a Raglan 5 lathe. Mine has 2 thou of run out on it so i think it is bent. the bearings are tight so i dont think the problem lies with the bearings. If i cant sort it out i fear a may have to scrap the lathe. thanks ian
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2 November 2010 at 19:08 #5271
Ian MILLARD
Participant
@ianmillard76204
2 November 2010 at 20:41 #58019
Steve Garnett
Participant
@stevegarnett62550
I’m intrigued. How exactly have you measured the runout?
2 November 2010 at 21:14 #58023
Ian MILLARD
Participant
@ianmillard76204
hi steve

I have used a dti mounted on a magnetic base, this was clamped to the lathe bed. A centre was fitted to the mandrill, i then rotated the motor pully by hand and measured the run out. I have also done it the same way but on the machined bit where the chuck locates.

IAN
2 November 2010 at 22:06 #58028
Steve Garnett
Participant
@stevegarnett62550
Hmm. If the bearings are tight and the spindle turns smoothly, that seems like a heck of a lot of runout, one way or another – and you have to make quite an effort to bend the spindle behind the front bearing…

I think that before I went to all the trouble and expense of getting a spindle remade – and it would almost certainly be cheaper to purchase another Raglan and cannibalise it, I suspect – I’d do two things. Firstly I’d get an engineer’s level and make damn sure that the lathe was as flat as you could get it in all directions, both ends. Then I’d mount up a chuck and turn a test bar (unsupported at the far end), and see how the diameter varied along the length of it. If the spindle really is bent, there will be no possibility of turning a bar the same diameter all along, and it would rather confirm that something was wrong. You should measure the diameter with a micrometer as well, especially don’t use a dti travelling on the saddle, because that is potentially going to cancel out some of the error you are trying to measure.

When you put the chuck on the lathe, you should be able to measure face runout on it as well, if the spindle is that bent, I would have thought.
2 November 2010 at 22:47 #58031
Steve Garnett
Participant
@stevegarnett62550
Incidentally, Harold Hall has covered the turning of test bars fairly recently in MEW, and there’s also details in Workshop Practice book 34. Really, I should also say in conjunction with truing the lathe bed that the primary objective is that it shouldn’t be twisted – the absolute degree of levelness isn’t anywhere near as important as that. It’s just that generally, it’s easier to use ‘level’ as a reference point for the exercise.
3 November 2010 at 02:38 #58038
John Olsen
Participant
@johnolsen79199
Twist in the bed would not show up as indicator runout on the centre or on the chuck register.

If the spindle is bent and you turn a test piece in the chuck with no support, then it will come out round and parallel, although not parallel to the piece that was held in the jaws of course. (Provided of course the spindle is actually parallel with the ways, if it is not then the job will be tapered one way or the other.) If it is bent then I would think the bend must be in the overhang, eg between the bearing and the chuck register. I don’t think it would be likely to be bent between the bearings without effects showing up, eg binding in the rotation.

There is some informzation on the Raglan lathes at lathes.co.uk , and it sounds like they would be a good place to ask about spares, otherwise you could try Myford since they bought the company towards the end.

regards

John
3 November 2010 at 09:01 #58042
KWIL
Participant
@kwil
Merely putting a centre in the mandrel is not a certain test, afterall if you want to turn “perfectly” between cenres it is often suggest that a soft centre is first trued up. If the Register (machined bit) is displaying that kind of runout, so close to the front bearing, then the mandrel would need to be so bent you probably could not rotate it! What is the diameter of the Register, measured at several different places (say 120 degees apart) ?
3 November 2010 at 09:01 #58043
JDEng
Participant
@jdeng
Ian,

Let me say at the outset that I’m not familiar with Raglan lathes however I would make a few suggestions which would probably apply to lathes in general. Some of it might be obvious and if so I apologise for teaching grandmother to suck eggs!

1) You say you have clocked (used a DTI) on what I presume is the register for the chuck on the spindle nose and on a centre placed in the morse taper of the spindle. There is a danger of introducing error by clocking on a centre in these circumstances; it would be safer to use the clock directly onto the inside of the morse taper if at all possible. If there is any muck or a bruise between the male and female tapers it will throw the centre out and show up as eccentricity.

2) Are both readings of eccentricity in the same place? Mark the spindle nose with a bit of felt tip and make sure.

3) Are there any bruises on either register or the inside of the morse taper?

4) You say the bearings are “tight”. I presume you mean there is no end float along the length of the spindle. Are they bronze bearings or needle rollers/ball races? Are they in good condition? Before you make any decisions I would strip and clean the bearings and make certain that there are no obvious problems with roughness or wear here. Reassemble and try the spindle nose and bore using the clock again.

I cannot see any misalignment of the bed affecting the eccentricity of the spindle nose personally; even if it it was so bad that it was putting a twist into the headstock I cannot see how it could make the spindle run eccentric for the type of checks you’re undertaking.

I undertake machining for a living and agree with what Steve says about cost; it would not be a cheap option to have a new spindle made but it might not amount to that.

Just as an afterthought, I appreciate that 0.002″ run out seems excessive but are you sure that is was not manufactured that way? As an example I’m in the process of altering an old Zyto lathe bed and cross slide to make a grinding rig for a job and the cross-slide was 0.010″ out of square across the bed both vertically and horizontally; there was not a significant amount of wear so it must have been made that way. It’s now been corrected but I was amazed that such low standards could have been deemed as acceptable!

Sorry if I’ve waffled but I hope this helps.

John.
3 November 2010 at 10:19 #58049
Chris Trice
Participant
@christrice43267
Oh, don’t say that. I’m restoring a Zyto as we speak. Having said that, the tailstock has been shimmed at some point because it was slightly too low in relation to the headstock. Ugh!

Edited By Chris Trice on 03/11/2010 10:20:38
3 November 2010 at 20:29 #58082
Steve Garnett
Participant
@stevegarnett62550
Posted by John Olsen on 03/11/2010 02:38:49:

Twist in the bed would not show up as indicator runout on the centre or on the chuck register.

If the spindle is bent and you turn a test piece in the chuck with no support, then it will come out round and parallel, although not parallel to the piece that was held in the jaws of course. (Provided of course the spindle is actually parallel with the ways, if it is not then the job will be tapered one way or the other.) If it is bent then I would think the bend must be in the overhang, eg between the bearing and the chuck register. I don’t think it would be likely to be bent between the bearings without effects showing up, eg binding in the rotation.

The only point in setting the lathe up carefully first was to remove other errors as best possible so that they didn’t interfere with the measurement that was actually sought. I wasn’t suggesting that bed twist would affect the headstock directly – sorry if you got that impression, because it wasn’t what I intended. John’s suggestion of clocking directly from the headstock morse taper itself rather than the centre sounds like an eminently sensible suggestion. And if it’s not used regularly, then giving it a good clean first also does!

But if there is a twist in the spindle behind the headstock, it will misalign the chuck, because it will make it run in the same way a bent drill will, so it will wobble about an axis somewhere in the front bearing. And if you turn a test piece, then the further you get from the chuck itself, the greater the manifested error. But if the bearings feel tight, and there appears to be no axial or radial play, the whole scenario sounds extremely unlikely, I must say. I’ve checked runout on two lathes recently, and I’d say that a value of about 1/10th of what Ian has measured would be a bit more like what I’d expect.
3 November 2010 at 20:32 #58083
Sub Mandrel
Participant
@submandrel
The one measureable error on my mini lathe is that the cross-slide is slightly out of line so the lathe faces slightly convex, instead of the normal concave. Only a couple of thou over 3 1/2″. I understand one early batch was ‘rogue’ and mine was one of them. I did plan to either remachine the ways or replace the carriage casting, but in ten years it’s only made a material difference to a handful of jobs.

Still it’s really annoying when everything else seems to be accurate to a much higher standard.

Neil
4 November 2010 at 09:38 #58120
Steve Garnett
Participant
@stevegarnett62550
Just as a matter of slightly more than idle curiosity, I just checked the runout on the newly-arrived (but needs work) Kerry’s 4MT headstock inner taper directly. With a Mercer dial indicator that indicates in 0.0005″ steps, I can’t see any runout at all – not the slightest flicker on the dial, after several times round. And yes, it’s working properly. So that’s probably good enough…!
20 November 2010 at 14:46 #58993
John Burridge
Participant
@johnburridge26484
ai run the Raglan Machine Tool web site on the Yahoo group web site,I am not sure but i may have a spare spindle for the Raglan lathes,both the Little John’s and the Raglan 5 inch uses the same spindle.

You could also post a request for a spare spindle there are quite a few members that have spares that maybe another port of call.

How are you checking for the spindle run out ?

yours for now

John Burridge

P.S. the website address is

http://groups.yahoo.com/group/RaglanMachineTools/
20 November 2010 at 15:40 #58994
Steamer
Participant
@steamer
If the bearings are “good”, you could also grind the taper with the spindle running on its own bearings. That would correct the run out. If the spindle is soft, you could even bore it.

You must get the angle corrcet and get the cutter on exact center, but it is attainable.

Dave
20 November 2010 at 16:44 #58998
colin hawes
Participant
@colinhawes85982
Hello Ian, I would be very surprised if the spindle is bent only 2 thou.It seems more likely to be the bearing fit. Are both bearings tight? or is one slack allowing the spindle to move as you rotate it? You should test the spindle for accuracy by removing it and laying its bearing surfaces on vee blocks and testing both its nose and bearing surfaces by rotating it under a dti.
20 November 2010 at 21:17 #59016
John Coates
Participant
@johncoates48577
There’s one on ebay as well

Raglan spindle
7 January 2011 at 12:31 #61916
Paul Smitherman
Participant
@paulsmitherman86321
Ian , Regards your Raglan Spindle , years back a friend of mine used to service all workshop equipment for the local county council , and when I told him I had purchased a Raglan Little John he said you know they have a weakness in the spindle , it is prone to bending .Especially if it has been in a college, The students run the saddle into the chuck

under power Result bent spindle , I asked him what the cure is and got the following reply

       Using the same chuck   fit a twelve inch long by one inch dia bar in and using the DTI rotate so the high spot is uppermost and with a No4 copperhide mallet give a smart whack downwards, I said sounds a bit brutal Yes he agreed but it works , when you have hit and re measured you can get a feel as to just how hard to hit in order to get back to zero   . I much later purchased an Ex college 5″ Raglan with just that problem and can now vouch that the chuck , and indeed the collets rotate without so much as a flicker from the DTI

        All in all I have found the Raglans to be very good , Have over the years made verious attachments and just recently found on the internet an Australian a chap who’es father was the agent for Raglans and aquired lots of parts some of which are surples to requirments   Hope this is of some help

Paul Smitherman
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