Faceplate or Independent Chuck?

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Michael Briggs on 22/10/2017 22:36:57:

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

[Michael BriggsParticipant @michaelbriggs82422]

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

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Michael Briggs on 22/10/2017 23:13:37:

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.

[Michael BriggsParticipant @michaelbriggs82422]

No problem at all, regards, Michael.

[Colin LLoydParticipant @colinlloyd53450]

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&quot chucks.

[HopperParticipant @hopper]

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.

[Tim StevensParticipant @timstevens64731]

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

[Chris TriceParticipant @christrice43267]

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.

[Ex contributorParticipant @mgnbuk]

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

[JasonBModerator @jasonb]

Posted by Colin LLoyd on 23/10/2017 10:33:33:

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.

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

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Nigel B on 23/10/2017 20:27:09:

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.

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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.

[Neil WyattModerator @neilwyatt]

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!

[Michael BriggsParticipant @michaelbriggs82422]

Is that a tumbler, MB ?

Nigel B

Hello Nigel, it is just a tin of paint ! Nearest thing on hand to show useful the 6” chuck to me. Would have been a better illustration if I had something big enough to extend the jaws in to the gap as suggested by Jason. Regards, Michael.

[JasonBModerator @jasonb]

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

[Ex contributorParticipant @mgnbuk]

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

[Colin LLoydParticipant @colinlloyd53450]

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.

[JasonBModerator @jasonb]

Please reply to the question about ER blocks in this new thread rather than let this one drift.

[Neil WyattModerator @neilwyatt]

Posted by Nigel B on 24/10/2017 07:35:34:

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

6" chuck internal capacity 2"

5" chuck internal capacity 1"

4" chuck internal capacity 1 1/4"

Looking at a Bison user manual their 125 and 140mm (5" and nearly 6&quot chucks both have the same internal capacities of 50mm internal and 125 external (2" – 5&quot. This is regardless of centre hight, which is interesting.

The 160mm has external capacity or 160mm but the jaws would definitely hit the bed of a 3 1/2" lathe if you tried that.

Clearly some chucks can be extended further than other (the 125 and 160 clearly are both designed to have the jaws sticking out by the length of the first step).

So the 'best' chuck for your lathe, if capacity matters most, is presumably going to depend on the design of the jaw securing screws more than it does on chuck diameter.

For a 100mm chuck they give 33mm internal and just 83mm external.

If you are ever going to use the 4-jaw to hold irregular or offset work the idea of keeping the jaws inside the outer diameter of the chuck is patent nonsense.

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