Plastic Chuck

[bjk896Participant @bjk896]

I have had a Unimat 3 for past 30 or so years used for a wide variety of projects and working with many materials.

I had always wanted an independent 4 jaw chuck to facilitate making bits from irregular stock as well as offset jobs

Naturally (!) I left it too late in life to get a "proper" one.

Following a very bad experience with an Indian supplier I came across an ad for a plastic 4 jaw independent. I have no idea what sort of plastic it might be made from.

Now, I've washed my mouth out and swallowed my pride and removed any concept of rip off from my mind as well as acknowledging that I would often use it to turn projects in PVC and Polypropelene and pose the question —

Would I be out of my brain to get one ?

Anyone with experiences with them and what materials have you used in them?

Comments please

[bjk896Participant @bjk896]

[Michael GilliganParticipant @michaelgilligan61133]

Very interesting concept … and potentially useful for the appropriate work.

If you can do so without breaching the ‘Code of Conduct’ …
could you please post a link [or at least a good hint] to the Seller.

MichaelG.

.

Ref. https://www.model-engineer.co.uk/conduct/

Edited By Michael Gilligan on 13/10/2021 13:26:36

[Jeff DaymanParticipant @jeffdayman43397]

I've worked in industry with plastics almost 40 years , doing tool design then product design and lots of home shop plastics work. Any plastic I have ever come across, even some exotic ones like PPS, PEEK, PSU, or metal filled epoxies, will not have anywhere near the rigidity of a steel or iron chuck. A plastic chuck MIGHT hold for very light cuts, but might not. If the work comes out while turning you could be injured and the chuck or lathe could be damaged. These risks outweigh any cost savings of a plastic chuck vs a steel or iron one. I'd say not recommended. in my opinion.

Just a thought re an alternate to iffy Asian chuck purchase – there have been a number of published designs over the years for home shop built chucks of various kinds. Some have been machined from massive blocks of steel with complicated ways and dovetails and fancy screws, by master machinists – but there have been a few made with basic steel weldments or screwed assemblies of simple gibs made of blocks and plates with commercial setscrews / grubscrews to tighten the jaws.

What diameter chuck were you thinking you need? What is the max swing diameter of your Unimat?

[Adam MaraParticipant @adammara]

Looks like its a part for the modern Unimat 1 Cool Tool 6 in 1, the question is, will It fit an old Unimat?

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Jeff Dayman on 13/10/2021 15:26:13:

I've worked in industry with plastics almost 40 years , doing tool design then product design and lots of home shop plastics work. Any plastic I have ever come across, even some exotic ones like PPS, PEEK, PSU, or metal filled epoxies, will not have anywhere near the rigidity of a steel or iron chuck. A plastic chuck MIGHT hold for very light cuts, but might not. If the work comes out while turning you could be injured and the chuck or lathe could be damaged. These risks outweigh any cost savings of a plastic chuck vs a steel or iron one. I'd say not recommended. in my opinion.

[…]

What diameter chuck were you thinking you need? What is the max swing diameter of your Unimat?

.

They have 1.79” centre height, Jeff :

**LINK**

http://www.lathes.co.uk/emco-unimat-3-and-4/

MichaelG.

[JasonBModerator @jasonb]

The Unimat 1 is an M12 thread so it won't fit a U3's M14 thread

I think Chronos and RDG do metal 4-jaws with a M14 x 1 thread and ARC sell backplates with this thread so you can fit chucks to those.

 

Edited By JasonB on 13/10/2021 16:37:13

[Howard LewisParticipant @howardlewis46836]

A chuck made of composite materialm is an interesting concept and could have its uses.

But being heavy handed, I would prefer steel or cast iron chuck.

And backplates are available for a variety of chucks, so that you can arrive at a combination that suits your needs

I am sure that Arc Euro will help with advice as to what you need

Howard.

[old martParticipant @oldmart]

Welcome, bjk, I personally think that you would be better off avoiding a plastic chuck, there will be plenty of common old cast iron ones available foro the suppliers advertising on this forum, not to mention ebay.

[Bill Davies 2Participant @billdavies2]

And I've been somewhat dubious about those diecast zinc chucks (google zinc lathe chuck). But they are cheap – is that their only virtue?

Bill

[bjk896Participant @bjk896]

Interesting comments thanks fellas

Apart from India do you know of a source for a 50mm (maybe 65mm OK) independent 4 jaw ?

I found it on ebay Australia website. It was a "Cool Tool" from Model Hobbies UK for $50AUD

[JasonBModerator @jasonb]

If you want a quality one without the stick out associated with a backplate and separate chuck then Sherline do their's with M14 x 1. Millhill Supplies are the UK agents.

Or you could buy an Emco one.

Other option is something like this backplate and a reasonable quality Indian chuck like this which may be a better make than the one you tried. Several members here have been happy with the Zither brand chucks.

[bjk896Participant @bjk896]

Just to clarify – My Indian experience was with the dealer not the chuck and resulted in a PayPal refund after 5 months, Begs the question – is there only one Indian manufacturer or several ?

For the lathe work I do, I'm quite happy to go India if I could be certain of the experience and the product.

JasonB – Thanks -the backplate option might be the way to go although setting it up might be a problem I shall look at resolving

[Mick B1Participant @mickb1]

I had a Unimat 3 for about 20 years, and the Emco 4-jaw was the only headstock chuck I had – couldn't justify buying the 3-jaw for the type and quantity of work I did. Occasionally I could use the drill chuck fitted on the headstock, but only on small work that obviously didn't need drilling.

The 4-jaw's a bit expensive for its size, but it does work properly – it's up to any job the lathe can reasonably handle, and, even if you can fit a plastic chuck, I suspect you'll be haunted for ever by its potential weakness and inadequacy if you ever want to machine metal. Just my 2p's worth.

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