Faceplate or Independent Chuck?

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Likewise

The Myford 'screwed body' 6" 4-jaw is very useful in the gap ... but decidedly limited over the bed.

MichaelG.

Yes, agreed Michael - but much of my work is fairly small, so we are back (as usual) to what sort of work the user will be doing?

I don't think the question is (or at least should be) really whether to get a 4-Jaw or a Faceplate - but simply which one should you get first (assuming nothing has been supplied in the first place). And the answer to that question (to my mind at least) is the 4-Jaw - but you will (eventually) need both...

Regards,

IanT

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No argument with that logic Ian, I just wanted to highlight that Myford's 6" 4-jaw is rather 'special purpose' and a smaller diameter might prove more useful.

That said [and very much dependent upon the work envisaged] it might be worth Colin looking at the use of 'dogs' on a faceplate ... (evolutionary ancestor of the 4-jaw)

MichaelG.

Not in my workshop.

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Could you elaborate please, Michael

MichaelG.

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Edit:

When I wrote 'but decidedly limited over the bed'  I should have said 'but a 6" would be decidedly limited over the bed'

Apologies if that caused any confusion.

Edited By Michael Gilligan on 22/10/2017 23:06:46

Had to nip out to take a quick photograph. The 6 inch four jaw is very useful to me :

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Thanks, Michael

It's fine because the jaws are running in the gap

... hopefully you have seen my edit, and we're in agreement.

... clumsy wording in my original post

MichaelG.

No problem at all, regards, Michael.

Good to see all the useful insight into this topic. I'd just like to take up Neil Wyatt's point about chuck weights. Surely the 4.5 kg mass of the 6" chuck, especially if compounded by an off-centre workpiece adding to the centrifugal forces, be more than the headstock bearings and motor power are designed for and would put great strain on these items. The C3 mini-lathe is probably not designed to take anything bigger than the 100mm (4" chucks.

Faceplates are relatively inexpensive. Get the more useful four jaw chuck first, then get a faceplate as well. The faceplate is the kind of thing you don't use very often, but when you do you it, you really need it.

Just a thought ... If you have a fairly big 4-jaw chuck, remove the jaws, and replace them with (home made) clamps, and you have the makings of a faceplate. If the chuck is front-mounted, use extended mounting screws (studding and extra nuts) and these are the basics for the clamps.

Cheers, Tim

I have both a 4" and 6" four jaw for my Super 7. They're both useful depending on the size of the work you're doing. If money is tight, a 5" four jaw would be a good compromise on a Super 7. I also have both the 7" and 10" faceplate and can say like someone else has, that I use the chucks at least ten times more than the faceplates, however, they are still useful and worth getting.

Surely the 4.5 kg mass of the 6" chuck, especially if compounded by an off-centre workpiece adding to the centrifugal forces, be more than the headstock bearings and motor power are designed for and would put great strain on these items. The C3 mini-lathe is probably not designed to take anything bigger than the 100mm (4" chucks.

A standard mini lathe appears to use 6206 deep groove ball bearings fpr the spindle. If you have a look at the ratings for a 6206 bearing, you will see that you will not have an issue with overloading them. A heavier, larger diameter chuck will be advantageous when doing interrupted cuts - it is a large flywheel & will help both the gearbox & the (relatively weak at low revs) motor under such conditions - mini lathe owners on other forums have fitted 5kg 5" 3 jaw chucks without problems & report better finishes using these..The heavier chuck does take longer to accelerate & decelerate, though. But if you feel happier with the smaller chuck, go with your feelings (just watch your digits if you run it with the jaws protruding !).

Not sure what MG means with regard to MB's picture - as the jaws are inboard of the 6" chuck body OD, the jaws are not running in the gap - a Myford will swing 7" over the bed after all. The jaws are running over the gap area, but not in gap.. That configuration would run without fouling on a C3, which also swings 7" over the bed.

Is that a tumbler, MB ?

Nigel B

That is what slim body chucks are made for, not only thinner so less distance from the bearings but also hollowed out at the back to keep the weight down. Neil's argument also fails if you ask him the weight of that lump of cast iron on his faceplate

Nigel , I think Michael was suggesting that a 6" on a Myford can be run with the jaws well extended beyond the body due to the gap.

Edited By JasonB on 23/10/2017 20:42:33

Edited By JasonB on 23/10/2017 20:47:27

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Mere semantics, Nigel

Longitudinally ... The jaws are running within the gap

and could if necessary [albeit not illustrated by MB] be opened beyond the diameter of the chuck.

A conventional Burnerd 6" 4-Jaw on a backplate does not permit such flexibility of use.

... and I am of the belief that either type of 6" chuck would be inconvenient on a C3

MichaelG.

I really can't see the point of a 6" 4-jaw on a 3 1/2" centre lathe without a gap bed.

Compare capacities on internal and external jaws, using the jaws at least 50% engaged for the Zither slim body chucks (p.s. the 4.5kg was for a slim body chuck):

6" - 3" on internal jaws, 5.5" on external jaws.

5" - 3" on internal jaws, 5.5" on external jaws.

4" - 2.6" on internal jaws, 3.5" on internal jaws.

So while a 5" chuck offers a gain over the 4", the 6" offers no benefit over the 5".

If you accept the 'minimum two threads engaged' rule the capacity of the 4" on its internal jaws becomes a bit over 3", that's MORE than the 4"or 5" chucks!

On this basis the capacity of the 4" chuck's external jaws is about 4.2".

So if you want maximum capacity, get the 5" not the 6". The extra cost of the 6" gains you absolutely nothing.

If you want almost all the capacity and the benefit of holding larger work securely in the inside jaws, get the 4".

THIS DOES NOT APPLY TO A GAP BED MYFORD BUT THE OP HAS A NON-GAP-BED LATHE!

Neil, are the zither slim chucks hollow at the back like the Bison and Burned?

If you accept the 'minimum two threads engaged' rule

I work to the " jaws fully engaged in the body with no overhang" rule wherever possible - "two threads engaged" is a new one on me & way outside my comfort zone.

How would your capacity calculations work out for full jaw engagement, Neil ?

Nigel B

OK you guys - I've gone out and bought a 100mm 4-jaw Independent chuck AND a 160mm faceplate for my CJ18A from those nice people at Amadeal - so I know they will both fit. It's an example of being between a rock and a hard place - and buying both creates a soft cushion to land on.

Does anyone have any thoughts on the new Arceurotrade Original Stevenson's ER collet blocks (square for 4-jaw and 6-sided for 3-jaw chucks. Seems to sort of turn my lathe into a horizontal milling machine - but I already have a vertical milling machine - so can't really see where I'd use these.

You can probably tell that I've now gained a mechanical version of GAS (Guitar Acquisition Symdrome) - I have 15 guitars (5 I made myself), 4 amps, and numerous effect pedals and other playing/recording paraphenalia - which my wife tells me is quite enough - but she doesn't go into the workshop so I can start again mechanically. I'm told there is no cure.