Is a camlock chuck with only two mounting pins common?

This chuck came with my monarch 16CY. It's a 15 inch 3 jaw scroll chuck with each jaw independently adjustable.

The lathe has a D1-6 spindle but the chuck adapter plate only has two pins. Feels to me like a beefy chuck like that should have all six pins.

What's the consensus opinion?

I agree that six pins would be normal. I had a rather large OEM faceplate for a Monarch 10EE (D1-3 mount) that had three pins and no unused pin holes, so I guess three is the minimum.

Larry

Absolutely six. Photo shows someone's unsafe effort. I have seen THREE on a collet chuck which has lots less FORCES to contend with

Are there holes for additional pins that have been plugged?

Illinoyance said:

Are there holes for additional pins that have been plugged?

Click to expand...

Yes, looks like they've been plugged.

That is one of those fancy, high priced "Quick Change D Series chucks", ;-))

I don't really know what to make of the chuck. I've been advised to learn how to dial in a 4 jaw and resist the impulse to get e three jaw scroll chuck and i've taken that advice to heart. Having said that, i have this thing and can't help but wonder if it's worth investing in a new backplate. I would still get a 4 jaw but am torn between a 12 inch and 15 inch. I'll have rigging over the lathe spindle so mounting/unmounting won't be an issue.

marka12161 said:

...can't help but wonder if it's worth investing in a new backplate...

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Given the condition of that backplate I certainly would. For a couple reasons:

a) A chuck that size with only two pins just isn't safe...
b) You run the risk of damaging the spindle of your lathe.

LKeithR said:

Given the condition of that backplate I certainly would. For a couple reasons:

a) A chuck that size with only two pins just isn't safe...
b) You run the risk of damaging the spindle of your lathe.

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Seconded, plus-plus.

No "risk" to it. You WILL damage the spindle. Chuck as heavy as that ain't no junior birdman's low-stress near-as-dammit right ON center 5C collet adapter.

Only thing as makes any sense atall was adapting that chuck to use as an indexer, a positioner on a bench fixture, or a low-stress grinding or polishing operation - even welding - but in any case OFF the lathe spindle altogether.

Such needs do exist, so it might have "seemed like a good idea at the time" to some prior Pilgrim who ALSO had a better chuck with all its "fingers" for use on the lathe and "the usual" work, this one simply available to re-purpose on-the-cheap, quick, dirty, and near-zero cost to address some other challenge effectively. No sin, that.

Most of us do much the same when we have those needs. WTF ELSE can one do with a mere THREE-Jaw chuck as ignored the "ban" and sneaked under the door by accident? Guess I shall have to buy a welder, now?




But it was whatever it was - stud mounting holes filled-in, not "temporarily borrowed"' a dead-giveaway.

I'd look it over closely, VERY, before spending a dime fitting a new back - which I always have one or more stashed, (D1-3 here) just in case.

Chuck may have been crashed, worn, or otherwise found wanting on strength, max RPM, or, or .. wotever...to have been sent-off to secondary duty in the first place.

3CW

The taper looks pretty much hammered anyway, get a 4 jaw and a new back plate.

That back plate is actually a dog driver plate, typically two pins, they used what they had laying around?

I had a Monarch K-13 lathe that only had three cam-lock holes for the D1-6 spindle, I wouldn't use anything less than that!

Kevin

I have seen 3 pins used on smaller chucks with D1-3 and 4 spindles. However a 15" chuck is quite heavy and the combination universal/independent chuck is heavier yet. (I have a few) Plus the added weight of the "work" would not be a good idea to use only 2 pins especially if the chuck is holding something that the machined surface is not in the center of the material mass. Not sure what size lathe you have but it seems to be quite large in that it will accept a 15" chuck. As to what size chuck you should tell us what size lathe. You can get another back-plate but it will be difficult to find one plus the cost will make getting another chuck less expensive. To add to the issue a 3 jaw chuck with independent adjustable jaws is not easy to adjust, 4 jaw Independent or Independent/adjustable chucks are much easier especially if you are learning how. On the other hand if you are learning how to adjust a 4 jaw chuck implies you have little experience running a lathe and trying to learn on a big lathe might not be a good idea.

Froneck said:

I have seen 3 pins used on smaller chucks with D1-3 and 4 spindles. However a 15" chuck is quite heavy and the combination universal/independent chuck is heavier yet. (I have a few) Plus the added weight of the "work" would not be a good idea to use only 2 pins especially if the chuck is holding something that the machined surface is not in the center of the material mass. Not sure what size lathe you have but it seems to be quite large in that it will accept a 15" chuck. As to what size chuck you should tell us what size lathe. You can get another back-plate but it will be difficult to find one plus the cost will make getting another chuck less expensive. To add to the issue a 3 jaw chuck with independent adjustable jaws is not easy to adjust, 4 jaw Independent or Independent/adjustable chucks are much easier especially if you are learning how. On the other hand if you are learning how to adjust a 4 jaw chuck implies you have little experience running a lathe and trying to learn on a big lathe might not be a good idea.

Click to expand...

It's a monarch 16cy. I also have a 14" Reed prentice. While certainly no expert, I have some experience running that smaller machine.

I’ve seen two different 12-14” d1-6 faceplates with three pins only. One came with a Monarch CBB I used to own.

Really strange the way four holes look plugged but two of the plugged holes have lock screw holes present and two don’t.

I’m sure there’s a story behind it all.