Ideal amateur lathe spindle nose?

[Niels AbildgaardParticipant @nielsabildgaard33719]

>**LINK**

 

Picture show a mutilated Boxford headstock casting.

A very scientific analysis by me (Are You listening Stockholm?) shows tha a spindle with 38 mm hole is possible if one buy two chinese bearings for less than 3 dollars each and can turn a new spindle.

>**LINK**

 

I will make a new picture of nose in mm,but my questio is what kind of nose will be best ?

Camlock,Thread,Kurzkegel,Big flange with three keyholes,ISO30,ER40 or whatever.

My present spindle is over 50 year and is not hardened and somehow still very accurate.

The new front bearing is 72/50/15mm and Box bearing hole is three inch or 76.2mm.

This hole is 30.1mm deep.

 

Edited By Niels Abildgaard on 05/09/2017 16:38:45

Edited By Niels Abildgaard on 05/09/2017 16:44:50

Edited By Niels Abildgaard on 05/09/2017 16:46:34

[Niels AbildgaardParticipant @nielsabildgaard33719]

[larry PhelanParticipant @larryphelan54019]

Camlock.

[Thor 🇳🇴Participant @thor]

Camlock or a DIN 55027 with bayonet ring fixing, this might be easier to manufacture.

Thor

[RainbowsParticipant @rainbows]

Might be worth going for name brand bearings for peace of mind.

A bayonet fixing ( BS4442) or a version of it with a step rather than a taper to directly take common chucks would be in my mind the best that can easily be made. Camlock could be difficult depending on your tooling.

If you are willing to lose 8mm off your bore you could add integral 5c collet nose. I couldn't think of a good way to add ER collets integrally cause you would need to make the spindle threaded for the nut.

[MWParticipant @mw27036]

Posted by Rainbows on 05/09/2017 18:18:09:

Might be worth going for name brand bearings for peace of mind.

I'm sure whilst most people will be able to find a decent branded size, when it comes to which brand in particular, I found it's best not to be too fussy because not all the different companies will make the size you are looking for necessarily.

Having said that, SKF seem to do a gazillion as a good first stop. 

Michael W

Edited By Michael-w on 05/09/2017 18:25:53

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Rainbows on 05/09/2017 18:18:09:

Might be worth going for name brand bearings for peace of mind.

.

Given that Niels is proposing to turn his bearing outers down to size; I suspect that the better the bearing, the more difficult the exercise might prove to be !!

There will, I think, be some interesting trade-offs involved in this job.

MichaelG.

.

See post on 03-September, here:  http://www.model-engineer.co.uk/forums/postings.asp?th=129383&p=3

Edited By Michael Gilligan on 05/09/2017 18:42:28

[Niels AbildgaardParticipant @nielsabildgaard33719]

Posted by Rainbows on 05/09/2017 18:18:09:

Might be worth going for name brand bearings for peace of mind.

A bayonet fixing ( BS4442) or a version of it with a step rather than a taper to directly take common chucks would be in my mind the best that can easily be made. Camlock could be difficult depending on your tooling.

If you are willing to lose 8mm off your bore you could add integral 5c collet nose. I couldn't think of a good way to add ER collets integrally cause you would need to make the spindle threaded for the nut.

I found the bearing in NSK catalouge and name is HR 32910J and am buying from bearingshop.com.

The chinese are sending people to the moon and europeans have trouble with immigration but make better technology?At least it is more expensive..

For the nose I am tempted to use ER inside and then considder the nut thing as a chuck and  screw it on like a any chuck.

A big integral flange is not really fun on a homemade spindle.

Outside like present Boxford but bigger and inside to take ER40?

I will do some sketching.

Edited By Niels Abildgaard on 05/09/2017 18:42:49

Edited By Niels Abildgaard on 05/09/2017 18:46:48

[Clive FosterParticipant @clivefoster55965]

If you can do the short taper accurately DIN 5507 with bayonet ring. Too many parts needing accurate setting up in a camlock system for a one off unless you have unusually good equipment.

L series is probably the easiest of the not direct screw fittings to get right as the basic fitting is simple taper on taper and doesn't come up against a flat face so a few thou endwise length error matters not at all. All the short taper systems theoretically need simultaneous fit on face and taper which is a right pain to achieve. Especially should you desire to buy in backplates as you need to match commercial dimensions and tolerances.

L00 is workable but possibly a little large. Commercial backplates expensive and not that common. But how many backplates does a guy need anyway. In your position I'd probably just roll my own "L-mine" fitting to whatever size seems OK and crank out half a dozen flange style backplates whilst set up to do the tapers and the keyways. That sort of job is basically shelling peas. Glue'n bolt plates to the flanges later to suit whatever you plan to put on them.

Cheap taper bearings won't do for a lathe spindle if you plan to do any decent quality of work. Bit more to a lathe spindle than a fancy tube too. There is reason why all lathes beyond the low cost variety use quality steels for the spindle Again were I to do such project I'd move up into the century of the fruit bat with nice modern plain bearings, independent pump fed lubrication and effective oil seals. Run the pump off a separate motor with a pressure controlled switch in the outlet line so the alter can't start until there is pressure for lubrication feed. Room for a real bore, oil country lathe style, in the spindle then.

Clive.

[Chris GunnParticipant @chrisgunn36534]

+1 for camlock, especially if you change chucks a lot. I remember a thread on one of the forums showing how to do it together with drawings, it may have been ME. Maybe someone else remembers where it was, but it showed that it can be done.

Chris Gunn

[Niels AbildgaardParticipant @nielsabildgaard33719]

Posted by Clive Foster on 05/09/2017 18:43:43:

Cheap taper bearings won't do for a lathe spindle if you plan to do any decent quality of work. Bit more to a lathe spindle than a fancy tube too. There is reason why all lathes beyond the low cost variety use quality steels for the spindle Again were I to do such project I'd move up into the century of the fruit bat with nice modern plain bearings, independent pump fed lubrication and effective oil seals. Run the pump off a separate motor with a pressure controlled switch in the outlet line so the alter can't start until there is pressure for lubrication feed. Room for a real bore, oil country lathe style, in the spindle then.

Clive.

When I got my Boxford I changed the bearings profylactic and utterly unnessecary.The new ones were chineese

and I could mesure no(repeat no ) runout using a swiss TDI? and a test bar from Arceuro.

What suitable steel say 70mm round can mere mortals buy and where?.About 300mm long

The only objection to simple screw on fitting is seizing with time and I have made it routine to remove chucks every evening.

 

Edited By Niels Abildgaard on 05/09/2017 19:01:47

Edited By Niels Abildgaard on 05/09/2017 19:02:32

[Niels AbildgaardParticipant @nielsabildgaard33719]

A picture with an ER40 collet

 

>**LINK**

Edited By Niels Abildgaard on 05/09/2017 19:58:06

[SteveIParticipant @stevei]

Niels,

 

Thanks for posting this interesting project. Now given your constraints and the scope being for the "ideal amateur lathe spindle nose" here are my thoughts:

 

Why have a big spindle and then ruin it with only ER40 collet nose? Why not go for ER50 (max 32mm) if you want ER? Having said that for the hobby user I am a big fan of the cheap 5C collets in round, hex, square and rectangular sizes.

 

I always think its best to use a standard spindle where you can as there is always great tooling about. If you can do it I would go for a D1-3 camlock and bore for MT4.5 and if you can, go for MT5. MT4.5 so you can use a reduction bush and MT3 centers and 5C collets as that is the smallest Morse taper with enough space for a 5C. 5C are cheap and are very nice to use with a draw tube. Now I know that the taper and face is non trivial to get right and in addition making the backplates for it is also not trivial and there are no D1-3 native dividing heads, indexers or rotary tables.

 

One of the advantages to the amateur is to use the same spindle tooling on an indexer, dividing head etc as you do on the lathe. So how about the Hardinge 2 3/16-10 threaded nose with an internal bore for 5C collets? Easy enough to machine yourself and also to make or source backplates. The specs are "published" and the perfect gauge available via commercial tooling. Every type of spindle tooling is available and it is still in production and lots of it is available second hand. It is robust enough to put a 6" 3 or 6 jaw chuck on it. You can put 30mm bar up the spindle. The only downside is running in reverse and I do not know how common it was in Denmark. Not unlike the original boxford nose but on steroids.

 

Good luck with the project.

 

Steve

 

 

 

Edited By SteveI on 05/09/2017 20:39:40

[JasonBModerator @jasonb]

One thing to watch with a collet into the spindle is that unlike say the Hardinge mentioned above where the chuck end bearing of the headstock overhangs the bed by a couple of inches the Boxford has a flat face to the head.

This may make it hard to get the carrage and toolpost close to the end of the spindle without excess tool overhang.

[Niels AbildgaardParticipant @nielsabildgaard33719]

Thank You for interest and sugestions.

I have never used 5C collets and feel uneasy.

If I shall make something outside ER40 I will rather bore soft jaws on a three what do you call it.

The beauty of the scheme is that I can make another spindle when I get wiser

A close up of present Box standard nose.

Are there some who find screw on really disgusting and why?

 

Where can I eventually se a Hardinge nose?Will bring some class to a Boxford I would say and it is not a mile of dimensionwise

Edited By Niels Abildgaard on 05/09/2017 21:23:25

Edited By Niels Abildgaard on 05/09/2017 21:25:28

Edited By Niels Abildgaard on 05/09/2017 21:26:43

Edited By Niels Abildgaard on 05/09/2017 21:27:48

Edited By Niels Abildgaard on 05/09/2017 21:28:23

[Neil WyattModerator @neilwyatt]

Screw on is simple to use and the cheapest option for the manufacturer (which is why it was so popular) but has some disadvantages:

• It can jam.
• It can unscrew in reverse.
• It is (even more) vulnerable to swarf in the thread or damage to thread or register (than other types) leading to or inaccuracies.
• Virtually all chucks will need a backplate.

Camlock is probably ideal for a production environment or if you can afford it. It's only disadvantages are cost and the need for a dedicated backplate for all chucks. It does take a modicum of understanding and care to use properly.

But you specifically asked about the best for the amateur. To me this means you need a secure, safe, simple and relatively inexpensive solution.

A bolt-on flange is simple enough for anyone to understand and therefore safe. Flange mount chucks are cheaper, a consideration for beginners. It's prime disadvantage is that it takes longer to use than camlock, but not much if you are used to it.

Another advantage, if you choose your flange dimensions wisely, is that you can choose a standard that allows you fit your commonly used chucks without the need for the extra cost, machining, weight and overhang of a back plate. This does not preclude you using backplates for other chucks.

So to reiterate, I think screw-on is an idea past its time, camlock is for jobbing shops where time is money and for more experienced hobbyists willing to pay the extra cost for added convenience. For ordinary amateurs, a straightforward flange is best.

I suspect camlock will be right for you, but if you choose a flanged spindle, use six, not three or four, holes so you can fit chucks with either three or four bolts!

Neil

[Niels AbildgaardParticipant @nielsabildgaard33719]

Thank You Neil for analysis.

I have never tried flanges but will.

It gives an awfull lot of swarf if spindle is made from round raw material but both Neil and Jason seems to like Flanges.

The mass producers in China probably forge or upset the raw flange.

The number of lathes with flanges to amateurs indicates that it is a tolerable system.

A friend has a WM280 machine like Jason and I will g and try chuck changing there.

Edited By Niels Abildgaard on 05/09/2017 22:00:17

[Nick HulmeParticipant @nickhulme30114]

Neils,
ER40 is very nice on the front of a lathe with a 30.5mm through capacity as collets are available up to 30mm for ER40, you might find it limiting with a larger through capacity, Collets are available to at least 34mm for ER50 though.

– Nick

[SteveIParticipant @stevei]

Neil, are these flange designs not short taper and face like the camlock?

Nick, where do you source 30mm ER40 collets? The largest I've seen are 1-1/8" and 27mm and these are special oversized with reduce wall thickness and lower clamping, not that I need the max clamping force.

Steve

[Thor 🇳🇴Participant @thor]

Hi Niels,

Unfortunately I don't have a Hardinge lathe, but here is a photo of the pindle nose. Better photos here.

Thor

Edited By Thor on 06/09/2017 06:25:33

[JasonBModerator @jasonb]

Neils, I can live with my flange mount as it is a cost effective method for home machines. Better with very little more effort to make is the keyhole DIN fixing

D1-3 or D1-4 would be nice but a lot harder to make the spindle.

J

[SteveIParticipant @stevei]

Posted by Thor on 06/09/2017 06:18:34:

Hi Niels,

Unfortunately I don't have a Hardinge lathe, but here is a photo of the pindle nose. Better photos here.

Thor

Edited By Thor on 06/09/2017 06:25:33

Those are photos of the No.5 4° taper nose, not the No. 5 threaded nose. They have over the years offered both types. I would not recommend to Niels to use that taper nose type at all.

I only suggested the No.5 threaded nose because it and chuck backplates are easy enough to make at home and it is very common on indexers, both old and cutting edge new. As I said a little bit like the original Boxford nose but approximately the right size for Niels planned spindle.

Steve

[JasonBModerator @jasonb]

Steve, any reason why not to use the taper nose, the couple of Hardinge owners that I know both rate the taper over the threaded version. They have made their own backplates without a problem.

[Thor 🇳🇴Participant @thor]

Sorry Steve, I missed the threaded part in your post, guess my old brain was having a senior moment.

Thor

[SteveIParticipant @stevei]

Jason,

I was thinking about the "amateurs" workshop comments and putting this into context in that Niels is taking on a job at home whereas others may have used their wallet to solve the problem. So with that in mind he needs an affordable solution. I.e. able to use the same spindle tooling in the home workshop on the mill. Second hand the threaded nose indexers and dividing heads are cheaper than the taper, as are the step chuck closers and faceplates. The are also easier to make. New, cheap Asian origin indexers are only available in the threaded nose type. Also if he has deeper pockets the servo/stepper motor indexers are also all threaded nose.

Steve

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