Which chuck to buy for first lathe ?

[JasonBModerator @jasonb]

Posted by roy entwistle on 07/12/2014 11:54:53:

Hi All Did anyone ever make a three jaw independant chuck?

Roy

A Combination chuck is probably closer than a Grip-True as each of the 3 jaws can be independantly adjusted with the key but they then also have a scroll so that all three will then open equally and return to the same shape when tightened. Handy if you have a batch of eggs to hold or multiple parts that are eccentric

[Chris TriceParticipant @christrice43267]

I'm genuinely surprised this even being debated to the degree it is. The three jaw self centring chuck is the obvious choice which again I reiterate is why all lathe manufacturers supply a three jaw as standard. If something needs holding to the nth degree of accuracy and someone feels their personal three jaw chuck is lacking, then you can always add cigarette paper or brass shims under the appropriate jaws to make it hold concentrically. Most three jaw chucks of reasonable quality hold acceptably well for the bulk of turning operations.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Ian S C on 07/12/2014 10:16:31:

I'd like a little 3 jaw chuck for my Super Adept, the 4 jaw chuck is quite fiddly to work with at this size.

.

Ian,

Have a look at the Bergeon set [third item on this page]

… Then get buying Lotto tickets !!

MichaelG.

.

[Chris: Please feel free not to look.]

[Neil WyattModerator @neilwyatt]

Considering the prices, the finish on a few of those accessories (tailstock and toolpost, for example) looks a bit less than perfect!

Neil

[john jennings 1Participant @johnjennings1]

Judging by the prices this gear is made of platinum!

Is this a first?

John

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Neil Wyatt on 07/12/2014 15:13:33:

Considering the prices, the finish on a few of those accessories (tailstock and toolpost, for example) looks a bit less than perfect!

.

Agreed … But unfortunately that appears to be the standard finish for the Model 50.

[from lathes.co.uk] … "Unfortunately, the model 50 model not only looked rather prosaic but was finished in a "hammered" paint finish quite out of scale with the size of the machine. However, the superb Bergeon quality remained unchanged and the lathe was every bit as good as it predecessors."

Previous models did look much smarter !!

MichaelG.

 

Edited By Michael Gilligan on 07/12/2014 16:56:21

[NJHParticipant @njh]

Good grief Michael !!

Many years ago I picked up, for not much money, a secondhand watchmakers lathe which came with a set of collets 0.4mm to 4.8mm in 0.2mm steps and, as I like the smaller end of things, this has been of use from time to time. I will certainly treat it with greater respect in future – indeed maybe a nice polished mahogany base and pride of place in the wife's display cabinet is more appropriate than the workshop!

Norman

( Sadly though it's not a Bergeon )

Edited By NJH on 07/12/2014 17:37:12

[Michael HornerParticipant @michaelhorner54327]

Posted by Michael Gilligan on 07/12/2014 11:01:57:

Posted by Michael Horner on 07/12/2014 09:27:20:

Posted by Michael Gilligan on 07/12/2014 04:14:43:

Posted by Brian John on 07/12/2014 02:54:29:

NOTE 1 : I have ruled out buying the 4 jaw independent chuck.

.

In that case, Brian … The choice between 3-jaw and 4-jaw self centering chucks is fairly simple.

• The 3-jaw will easily and securely hold round and hexagonal material.
• The 4-jaw will easiily an securely hold square material.

Yes, the 4-jaw will probably hold round material, but less reliably than the 3-jaw.

… holding most other sections will require some initiative.

MichaelG.

Hi Michael

Why won't a 4 jaw chuck hold round material as well as a 3 jaw?

I seem to rememeber that clever chap in the US who made the laser centering device for the mill spindle has a website, someone posted a link and I had a look. One of the things he said was that he preferred a 4 jaw independant over the 3 jaw indepandent because it would grip round, hex and square bar.

Grey matter could be off, it's not doing very well at the moment

Cheers Michael.

.

Michael,

I think Neil has probably answered most of this on my behalf, but here goes …

• Brian has already ruled out the 4-jaw independent
• I was therefore talking explicitly about 3-jaw vs 4-jaw self-centering.
• For your homework, today read about kinematics …
• why do photographers and surveyors use Tripods?, and why does a milking stool have three legs?
• Extrude that point contact in the Z-axis and you have three lines
• At the limiting condition; when real surfaces meet, there is only ever three point contact … anything more will involve [perhaps microscopic] distortion of surface[s].

Now, translating all of this to the self-centering chuck question: The 4-jaw will grip round stock less reliably for the same reason that a four-legged chair might wobble on a floor [whereas the three-legged stool will never do so].

The independent 4-jaw is, of course, a different matter.

And, by the way; the 3-jaw self-centering will grip any shape … provided that it has constant cross section along the length … it's just that the centre will be wherever it falls naturally.

Hope that makes sense … happy to discuss further, either here or by P.M.

MichaelG.

Hi MichaelG and Neil. Apologies to the OP.

Dan Gelbart was the name of the US guy I was thinking of, this links you to one of his youtube videos. **LINK**

About 3/4 of the way through he talks about using a self centering 4 jaw chuck. He has a bit of an accent so I may have miss heard him. Hearing gone south as well

I think I hear him say 4 jaw independant is a boon for R&D and precision work.

I shall cross him off my christmas card list and thanks for saving me £80

Mind you his lathe probably cost more than my house

Cheers Michael

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Michael Horner on 07/12/2014 19:16:05:

Hi MichaelG and Neil. Apologies to the OP.

Dan Gelbart was the name of the US guy I was thinking of, this links you to one of his youtube videos. **LINK**

About 3/4 of the way through he talks about using a self centering 4 jaw chuck. He has a bit of an accent so I may have miss heard him. Hearing gone south as well.

.

Michael,

Thanks for the reminder about Dan Gelbart's remark … Very interesting !

I have just checked his video, and I think he's recommending a self-centering 4-jaw.

It's very brief, but he does appear to show a self-centering 4-jaw gripping a hexagon at four points [lines]. … I must admit, that's counter-intuitive; but it's food for thought.

That said; I do stand by my opinion on the kinematics.

MichaelG.

.

Edited, and hopefully clarified.

Edited By Michael Gilligan on 07/12/2014 19:53:46

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Michael Gilligan on 07/12/2014 19:42:41:

… It's very brief, but he does appear to show a self-centering 4-jaw gripping a hexagon at four points [lines]. … I must admit, that's counter-intuitive; but it's food for thought.

.

Well … I thought, and I browsed and: Yes, it does work geometrically.

Look here, at the diagram for the largest square within the hexagon. The four intersection points prescribe the locations at which the external chuck jaws would need to act.

The practical usefulness may depend on the shape of the chuck jaws, but the theory is good.

The day is not wasted … I have learned something.

MichaelG.

[Neil WyattModerator @neilwyatt]

[Steve WithnellParticipant @stevewithnell34426]

I hope you are not suggesting one of those six jaw self centring chucks?

What are they for anyway?

[MuzzerParticipant @muzzer]

Thinwall tubing mainly.

[Brian JohnParticipant @brianjohn93961]

Well, I have waited patiently for 4 months for the Sieg C0 lathe to come back into stock but still no luck. Today I found this lathe (OPTIMUM) on the internet. I have not considered this machine before ; it looks like a much better option and it only weighs 24 KG. Has anybody had any experience with these lathes ? They may use a different brand name in the UK.

**LINK**

[VicParticipant @vic]

Is this a suitable size?

**LINK**

[Brian JohnParticipant @brianjohn93961]

Yes it is but I do not think that lathe is available in Australia. I have not seen it before.

[Ian S CParticipant @iansc]

Brian, that looks a quite serviceable little lathe, if you can go along with a hand full of cash, and see if they will throw in a 4 jaw chuck. When I bought my lathe, I bargained between 3 different places for a couple of months, and got about $NZ1500 off the price, about 50%. A good Chinese lathe should come with a 3 & 4jaw chuck, a face plate, fixed & travelling steadies, 2 centres.

Ian S C

[AjohnwParticipant @ajohnw51620]

Some how I doubt if it's been mentioned and probably mostly of no interest at the smaller end but the 4 jaw independent will hold work far more securely than any of the self centring chucks.

This can be of interest where people have fitted a far more powerful motor so that they can drill larger holes in one go and in cases where there isn't much to hold on to. Might be of some interest in training establishments too because there isn't much chance of work being gripped unevenly. as it can be in a 3 jaw particularly short and or heavier pieces of material. Or any piece of material in some cases.

When the 4 jaw chuck is used like this there isn't any need to centre precisely. That only usually happens when work can not be done in one setting and the 3 jaw isn't accurate enough.

John

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[Nitai LeviParticipant @nitailevi73768]

Maybe I missed a post where you changed your mind about the Sherline lathe…?

I had a Sherline lathe for years and in most of that time used only the Sherline 3-jaw chuck. It is pretty accurate and I didn't need higher accuracy than I could have with it during that time. The main reasons I changed were that I needed more swing and using a compound was a bit uncomfortable (needing a setup). For its size I thought it was really excellent.

The "sticks" for tightening are less convinient than a chuck key on a standard lathe but it was a little more convinient to get the chuck almost tightened with my hands and only then use the sticks. I only dropped one a few times during all those years, not a big deal.

I had a piece slip a couple of times, but that was mostly because I was really pushing the lathe and needed a larger one. I've never had a problem otherwise.

I wish my Sieg had the same out of the box quality as my Sherline…….

[Brian JohnParticipant @brianjohn93961]

The Sherline lathes cost twice as much. A few people did say that they were not all that good but I think they were biased towards the Sieg machines.

[MadMikeParticipant @madmike]

Brian, I don't know where you are located but ArcEurotrade show the Sieg CO as in stock today. Their ad is on the right.

[MadMikeParticipant @madmike]

Brian Ausee, ad also on the right, are in Australia and show the Sieg CO in stock with an accessory pack. HTH.

[Brian JohnParticipant @brianjohn93961]

I bought TWO Sieg C0's from Ausee last year and both arrived damaged. They had to be sent back for a full refund. I do not blame Ausee for this ; it was caused by careless freight handlers. Ausee will not sell me another C0 and I am not surprised !

Melbourne Tool Shop had one Sieg C0 in the shop a few months ago and I bought it online. But a few days later I saw that I had been given a full refund to my paypal account. Upon inquiring they said that the machine would not work when they tested it prior to sending. They never did get any more in stock.

I was not meant to own a Sieg C0 ! I bought three of them and ended up with none

[martyn nutlandParticipant @martynnutland79495]

Brian

If this is your first lathe and experience of latheing don't, please don't, land yourself with a four jaw independent as your only chuck.

Whatever you're told, whatever you see on internet videos and YouTube, setting it up will drive you absolutely stark raving bonkers and most likely put you off your hobby for life. Centring an independent is hell, unless you're a trained, operator, and have been doing it since you were an apprentice. It takes me, someone, I guess like yourself, for ever and is still slightly off.

Also, a dial indicator is absolutely essential. My humble suggestion, as a relative beginner myself, is get a three-jaw self centring chuck and you will be latheing away virtually from the moment you get your Sherline. Learn to use the dial indicator on work in the self centring type, then get your independent chuck. But then be prepared to be very, very patient.

Good luck.

Martyn

[NJHParticipant @njh]

OK Brian – back to your original question!

So,as to chucks!

You will eventually need both 3-jaw self centring and 4-Jaw independent chucks. Sure it is possible to manage with just the 4-jaw but, if you are new to this game, what you need now is to use your new machine, cut some metal and gain experience! The best way to achieve this is with the self centring chuck so get that and then start saving your pennies for the 4-jaw.

I don't know about other forum members but my lathe lives with a standard 3 jaw in place. (I do also have a 3-jaw GripTru, a 4-jaw self centring, a 4-jaw independent plus a set of ER collets!) The chucks are changed according to the work at hand but the standard 3-Jaw S/C gets most use.

Norman

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