New lathe arrived today : The ongoing saga

[Brian JohnParticipant @brianjohn93961]

I whole new tailstock assembly will be ordered on Monday…bloody thing ! You never realise how much you need the tailstock until it goes wonky on you. It will probably take 6 months to arrive if past experience with this brand is anything to go buy.

ALWAYS buy a well known and trusted brand of lathe so spare parts are easily obtainable and you do not have to wait.

[SillyOldDufferModerator @sillyoldduffer]

Posted by Hopper on 18/02/2016 07:04:40:

Have you checked for swarf in the moving parts and burrs on the barrel / Pinole (WTH is a pinole anyway?) along the groove where the grubscrew 404 locate?

Pinole is German for barrel or quill. Probably indicates that the manual was translated into English from German.

[Brian JohnParticipant @brianjohn93961]

The tailstock seized up again. I pulled the whole thing apart and put it back together removing all the burrs this time. Things seemed to be going well for a while then I noticed the dead centre wobbling about. I might just order a whole new tailstock ($180) rather than trying to sort this one out. But they do not keep any spare parts in Australia so parts may take months to get here. You do not realise how necessary the tailstock is until it stops working !

Edited By Brian John on 06/03/2016 09:43:51

Edited By Brian John on 06/03/2016 09:44:27

[AjohnwParticipant @ajohnw51620]

Couple of things Brian.

Are you wiping things like the tailstock quill over with oil now and again ? Is there an oiling point and do you use it? If there isn't an oiling point it would probably be best to remove the quill now and again and put a bit of oil on it and the thread in the end of it. Same goes for however the handle is held in place but a bit of grease would be best there between parts that rotate against each other including bores and shouldn't need doing very often.

Your best bet for oil where you are is probably grade 32 hydraulic oil. It needs to be a mineral oil and these are. I can't see any on ebay oz, only stuff for cars etc. The type needed is the sort used in JCB's and fork lift trucks and things like that. You may need to buy 5l so it will last a long time. It's reasonable stuff to use on the lathes slides as well so if you are going to have a lathe it's worth having around which ever one it is.

Then the tailstock itself – I only just looked before more rabbiting

If I had one like this jam up the first thing I would look at is the axial parts from 408 to 413. The end of the handle might be too hard on the 408 bush. The thread in the handle and the nut form a lock nut famous for loosening over time so when you use the handle it screws down hard on the the bush. The same thing can happen on slides made this way. A better option is a keyway. The bush might move under load. 1/2 drills are BIG for this machine. The talstcok quill is only used as a support for a die stock to square it up not to force it on and each time the chip is broken the tailstock has to be moved back from where it was.

Pinch bolts are a bit of a pain. They are only intended to pinch things not clamp them up rock solid. When drilling they should be slackened right off. It's the fit and the length of the bore outside of the pinch area that looks after the alignment. I suspect this area might be your problem looking at the end of the quill in the photo or / lack of oil and or condensation – it looks a touch corroded. I can't see how 404 could get over tightened – that should have a round thread free part on the end which is a nice fit in the slot in the quill. Wouldn't surprise me if all Baby and similar lathes didn't have.

If the pinch bolt needs to be used because the spindle fit in the bore is so so a lot of care is needed. The quill still needs to be able to slide through it fairy easily and the screw feed provides a lot of mechanical advantage. Sound like the fit was pretty good.

If 408 jammed when you were getting it out you probably knocked it out of square. That would cause it to mess up the bush and the area it sits in. If you want to do that sort of thing easily it's best to find something with a square end near the diameter of the bore so it can't knock it out of square.

If they are not hardened the ends of quill can expand out a bit due to the morse fitting. They can anyway if the tapers are slightly out. Either way- something to watch out for – getting slightly stiffer when the quill is fully drawn in. It's less likely to happen on substantial quills. Many lathes have rather low diameter quills.

John

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[Brian JohnParticipant @brianjohn93961]

I strongly suspect that there are a couple of smaller problems adding up to one big problem. The quill was a bit rusted at the time of the photo but I put it in the lathe chuck a few weeks ago when it first jammed up and gave it a polish with 1500 grit wet and dry. I then gave it a good coat of light machine oil and it fitted nicely. I was surprised when it jammed up again today but I think you may have found the reason : the ends of the quill can expand out due to the morse fitting.

I am sure there is also a problem with the grub screw that fits in the bush and holds it in place. The thread on the grub screw cuts into the bush as it turns thus preventing the handle from turning smoothly. This really should be a smooth pin/grub screw combination rather than just a grub screw ie. the pin part should sit neatly in the slot on the bush. The slot on the bush is also a V shape ; I don't really think that is helpful either.

My first attempts to rectify the situation may have made things worse so now I have a bit of a mess on my hands. I will have a look at it again tomorrow after re-reading all that you have written above.

NOTE : there are no oiling points that I can see.

Edited By Brian John on 06/03/2016 16:52:40

[HopperParticipant @hopper]

Good point on the tailstock quill possibly expanding outwards under pressure from the morse taper up its spout.

A bit of careful measurement and experimentation should confirm/disprove this. Probably the only easy remedy would be to chuck up the quill and machine or sand down the diameter to parallel all along the full length.

You could make a new quill out of tougher steel such as EN8 (aka 1040) or an old shock absorber piston rod out of a large 4WD or small truck might be about the right diameter. Scrounge around Pedders or Fulcrum suspension shops down Scott St way and you might find a dumped shockie that could donate the right material.

[Brian JohnParticipant @brianjohn93961]

I do not think that is the only problem. The main problem now is the bush and the screw that hold it in place ; rough as guts. The bush is also hard up against the handle and I cannot move it after taking everything apart.

[Brian JohnParticipant @brianjohn93961]

The bush (408) has ''cemented'' itself onto the hand wheel (410). Does anybody have any suggestions as to how to get them apart and why should this happen in the first place ie. how to avoid it happening again ?

[AjohnwParticipant @ajohnw51620]

That oil I mentioned earlier Brian, a little maybe every few weeks. That area would have been the first thing I would have looked at.

There is bound to be some one around that sells hydraulic oil but you may have to buy 5L. If you are going to have a lathe or other machines you will always need some around. They are straight mineral oils which is what you need. All the bright parts need lightly coating with it periodically especially it seems where you live. It might even need doing daily.

I take it you have undone the nut in the middle of the hand wheel? And then unscrewed the lead screw. A rap with a mallet should get it off then but don't do that with the leadscrew passing through it.

Edit Actually around the bush a bit of grease would probably last longer. Maybe on the lead screw as well but do use oil on the barrel now and again.

John

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Edited By Ajohnw on 19/03/2016 11:14:54

[Brian JohnParticipant @brianjohn93961]

I took the tailstock apart again today but I have had no luck shifting that stuck bush. I wrapped it in some thin brass to protect the bush and placed it in a vice to grip it but it will not move. Any suggestions ?

[AjohnwParticipant @ajohnw51620]

You may well find the handles has a screw thread in it so needs "screwing" off.

John

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[HopperParticipant @hopper]

Yes, I would think you might need to unscrew the main handwheel first then unscrew the sleeve.

Or look for a way to clean up the bushing without removing it, eg spin the whole assembly in the lathe with a fixed steady (did you get one yet?) etc.

If you want to get hydraulic oil in small quantities,get a litre of compressor oil from Bunnings. Or synthetic engine oil works just as well too. It does not go gummy like dino oil.

[Brian JohnParticipant @brianjohn93961]

Nothing will move…that includes the wheel/handle.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Ajohnw on 20/03/2016 08:50:32:

You may well find the handles has a screw thread in it so needs "screwing" off.

.

Brian,

John is quite obviously correct ^^^

The internal thread is shown clearly on the exploded diagram.

You will need to find a way of gripping the large screw-thread, and the knurled handwheel, without damaging them.

MichaelG.

 

Edited By Michael Gilligan on 20/03/2016 09:29:37

[JasonBModerator @jasonb]

As Michael says try gripping the long thread in your vice with a piece of wood either side to protect it from the jaws. Wrap something around the handwheel to protect it and then a pair of gland pliers or similar to undo it.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by JasonB on 20/03/2016 10:10:11:

…and then a pair of gland pliers or similar to undo it.

.

or maybe even one of those 'strap wrench' gadgets, made for opening difficult jars.

MichaelG.

[AjohnwParticipant @ajohnw51620]

When you put it back together screw the handle on to set the free play / amount the bush can be moved, Then lock the handle in pace with the nut. This is a pretty general way the Chinese lathes hold the handles in place and set the free play. That's why I would look at this and the same on other feed handles if things changed.

Bush movement back and forth – few thou but do grease it up first. I'd look for a gp long life /low maintainance grease. You'll probably find a small tube of synthetic on ebay or local motor factors etc.

Personally I'd stick with hydraulic oil of the grade I mentioned. You may be able to get 1L of that too. Engine oils stinks fume and will also probably take up water. Doesn't matter in an engine as they run hot.

John

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[Brian JohnParticipant @brianjohn93961]

I tried the timber in the vice to hold the long thread but no matter how tight I screw the vice, the thread still slips against the timber. It is really stuck on there. The odd thing is that the scale wheel which is between the bush and the hand wheel still moves freely. I would have thought this should be jammed too.

Any suggestions as I am out of ideas at the moment ? I could try the blow torch on the bushing to see if that will expand it slightly but I want to run it past a few people first.

[JasonBModerator @jasonb]

Your little drill vice is probably not upto it, really needs a decent size bench vice.

The scale wheel is only a friction wheel so it can be reset to zero so one would hope that it does rotate.

I doubt heat will help without getting it very hot and that will possibly damage the soft handwheel, if some galling has taken place then heat won't help much either.

[Michael GilliganParticipant @michaelgilligan61133]

Brian,

One detail that worries me a little …

The exploded diagram that John copied [from p69 of the manual] has a "bubble" numbered (414) which is poorly positioned but, according to the list on p70, the item is a Spring.

… With the benefit of having the assembly on your bench; are you comfortable that you understand where (414) is, and what it does ?

MichaelG.

.

P.S. The number is barely legible on John's jpg crop, but is reasonably clear in the pdf.

[Brian JohnParticipant @brianjohn93961]

I do not have any spring 414 : maybe this is the cause of all my problems ! Where is it supposed to go ? There is nothing at all marked on the tailstock exploded diagram..is there ?

On page 67 there is something (a spring or clip ?) marked as 527…I think. It is supposed to fit over the bush. I do not have this item at all and I have never seen this before. Considering the dickhead way they assembled the clutch mechanism it would not surprise me if they left this thing out altogether !

Thank you very much for drawing this to my attention.

Edited By Brian John on 23/03/2016 09:18:31

[JasonBModerator @jasonb]

Probably a small spring to impart friction on the scale so it does not turn on its own but can be set to zero with hand pressure. Even if missing I don't think it would jam things up.

Is there a hole in the back face of the handwheel Brian? that the spring could fit into?

[Brian JohnParticipant @brianjohn93961]

Do you mean the outside of the hand wheel ? I can see no hole there. If you mean the inside somewhere then I will have to remove the hand wheel from the main screw which is something I cannot do at the moment.

[JasonBModerator @jasonb]

Yes on the inside face where it meets the scale, thought you may have noticed it last time you had things apart.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Brian John on 23/03/2016 09:17:38:

I do not have any spring 414 : maybe this is the cause of all my problems ! Where is it supposed to go ? There is nothing at all marked on the tailstock exploded diagram..is there ?

.

Look carefully at the exploded view:

(414) is cunningly camouflaged by the knurling on the handwheel.

MichaelG.

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