Chucks

And lets face it a new Myford comes with a 3-jaw as standard, no 4-jaw. They can't be wrong

As a wee bit of an aside, wood turners use more or less identical 4 jaw self centering chucks to metal turners. To produce an off-centre turned piece of wood, the jaws and be put in the chuck in the "wrong" order, eg 3412, 4123, etc rather than 1234. Not for the beginner or the faint-hearted but it's effective (ideally needs tailstock support etc). I don't suppose this technique is used much for metal ....

I think it's got something to do with how quick it is to let a potential customer try out a lathe on a demonstration, you wouldn't want a showroom full of myfords on 4 jaw chucks.

In fact, why don't we ask warco, chester, sherline, axminster, Clarke, taig etc, to reconsider their age old wisdom of selling 3 jaws with the machine,

explain to them that they'd be doing their customer a favour with good habits regarding to accuracy and component diversity, and see if they buy it. 

A lot of people know about 4 jaw self centering chucks, but come to think of it, I've only seen a 3 jaw independent chuck just once in my life. 

Michael W

Edited By Michael-w on 23/05/2017 13:00:20

I trained professionally and never came across this silliness. Both in the apprentice training centre at the car factory and the toolroom machine shop, and at tech college, three jaw chucks were the norm. Four jaw was only used for something special, either high precision concentricity of an existing diameter, or gripping an odd shape. Insisting that apprentices use a four jaw for all jobs may be a good learning exercise but is a big waste of time really.

Only time it could be an advantage is on large lathes where a chuck change involves using a block and tackle etc so you tend to leave the four jaw on the lathe and get adept at quickly truing up round jobs but usually the material is sufficeintly oversized that rough truing with the tool bit or a bit of chalk rather than a clock suffices. Or a smaller three jaw chuck was gripped in the four jaw for general jobbing work. So not relevant to mini lathes etc.

I'd be a bit cautious about those aluminium jaws on the three-jaw though. Never come across that, other than special soft jaws, for everyday use.

I think it starts to become a bit scary with the larger chucks to think that the ally jaws probably don't have a very good grip on it. (and therefore more liable to fly out!).

Michael W

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3 jaw / 4 Jaw. It all depends on what you intend to make.

For me :-

1st project was a James Coombes engine. - Used a 4 jaw quite a bit on that.
2nd project was a No.4 - Used the 4 jaw a bit but not as much as for the JC
3rd project was a Hoglet - Used the 4 jaw very little.
4th project (98% finished) Hit and miss engine. - The only thing from memory I used a 4 jaw for was to drill and tap the valve push rod and some work on the cylinder head that could have been really done on the mill.

I have 2 4 jaw chucks. A 100mm and a 150mm. There have been times away from model making when I have used the 150mm as my 125mm 3 jaw was not quite big enough.

As I said previously if I were to buy a 'mini lathe' I would probably have an ER32 chuck fitted to it most of the time. Or if I wanted to be really posh like that Jason bloke I would buy a set of 5C collets with a morse taper to fit straight into the spindle. But he has a larger machine so uses a chuck not the spindle taper. 

Nick

Edited By Nick_G on 23/05/2017 13:31:51

Although I'm quite happy and capable of using my 4-jaw when needed I'd be interested to know what sort of accuracy those that can set their 4-jaw "in a minute" with a bit of chalk, fag paper, end of tool, etc can get. I'm assuming its is less that 0.0005" TIR as that is what my 3-jaw gives which you are all saying is inaccurate.

You're a lucky man indeed, and that chuck is worth treasuring. I've got mine set up to where it is within .002" most of the time and reckon that is pretty good going. Seems to suffice for almost everything I do. I would say I use the three jaw for at least 75 per cent of jobs. No need for repeatability - I just machine everything in one set up . If needed, I can screw the chuck off with job in situ, but can only think of once that I did that to check a fit of the job into a part too big to lift up on to th elathe.

.

And I happen to know he paid only £100 for that 125mm chuck brand new.

Nick

And its mounted straight onto the old Warco backplate that teh supplied chuck was originally on that ran quite well too!

Can't beat a good Chinese

I'll confess, it's marginally more accurate than my £100 Indian 3-Jaw

Neil

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Do they have Chinese takeaways in Poland.?

Nick

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On the subject of 4 jaws.

While not for the OP but for the Myford user this looks like a very good buy. **LINK**

Nick

Removes the bother of machining a back plate, I suppose, and we all know how awkward that can be. That alone has to be worth it for £40.

Which is exactly what I have to do for my 4" 4 jaw slim zither chuck! which set me back about £90. probably more like £110, If I include the cost of a 5" RDG backplate casting. 

Michael W

Edited By Michael-w on 23/05/2017 18:26:04

Horses for courses. 3 jaw is fine for non precision work and precision work if you can complete all operations without removing the job from the chuck. I use both. I got a lightweight Burnerd 4 jaw from the Harrogate show a few years back for £90 and it is superb. I did a technical apprenticeship and had 3 weeks of turning and rarely used the 4 jaw. I will say though that if the OP is concerned over the cost of a second chuck, he is in the wrong hobby. Tooling will soon empty your pockets

I realise that its not a cheap hobby but I would rather not empty my pockets before I have even started if I can get away with one chuck instead of two. The consensus appears to be in favour of a 3-jaw, it will at least get me started. I don't know yet what I shall be making but it will obviously be something small, I am looking forward to finding out. Iwould like to thank all those who commented, there was certainly a lot of info that I will try to take in.

Hey Brian - you've learned one of the most important lessons in Model Engineering Forum.

The easier the question seems to the uninitiated the more steam and posts it generates!

A while back I asked what size pilot drill for an M8 bolt ..... 300 argumentative posts later ..... I had 300 answers.....

Iain

The way I look at it at least you can get on with turning something on a self centre, you could learn the hard way, just go for the 4 jaw and see how frustrating it is to get right when you've never used it before (especially on a round bar, as it's harder to judge which jaw is out). Let alone the turning, you'd just be throwing an unnecessary obstacle in your way.

Obviously there is always going to be a preference but for a beginner in mind, I would definitely advise against it and it's easy to see why.

Michael W

Edited By Michael-w on 23/05/2017 20:54:06

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It's sold. - So fess up now. .............. Who bought it.?

Nick

On the subject of the Taig 3 jaw chuck.

The chuck is 31/4" diameter so definitely in the small category. It is available with either aluminium or steel jaws. For a new starter, ordering the chuck with steel jaws may be the better option.

The description of the aluminium jaws (ex Australian website but probably taken from the Taig US website) is that they are to be treated as typical soft jaws, i.e. set up (machined) for each activity.

When I last purchased a set (in Australia - land of the falling dollar) they were quite cheap and could pretty much be regarded as a throw away (machine away) item.

As an aside, it is well worth browsing through the Taig US website to see just what is available in the way of options and accessories for the Taig lathe (and milling machines). Probably almost as many as for the Myford

Pero