Is 16 inch 4 jaw too big for monarch 16 CY (18.5 in. swing over ways)?

I've got an opportunity to buy what looks to be a nice used chuck for a decent price within driving range but am wondering if something in the 14-15 inch range might be better. Chuck weight and speed are not a concern as i'll have adequate rigging and the spindle speed is low.

My other lathe is a 14" swing and i have a NOS 10" bison which seems just right.

Not if you pay attention to jaws hanging out beyond OD

I have a 16 for the 16" CW - just never put it on yet

Since it has tee slots it can double as a face plate (with jaws removed)

Yes, a 14 or 12 would be better...Phil

marka12161 said:

I've got an opportunity to buy what looks to be a nice used chuck for a decent price within driving range but am wondering if something in the 14-15 inch range might be better. Chuck weight and speed are not a concern as i'll have adequate rigging and the spindle speed is low.

My other lathe is a 14" swing and i have a NOS 10" bison which seems just right.

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Max of one and one-quarter-inch jaw hang-out beyond the body? Probably with jaws reversed?

Could need that. But ... how likely that you'd ever be in such a tight spot as to utilize it .... ever. At all?

Lots of work also has to clear over the cross..

I'm better served with an 8" for the 12.5" 10EE's... and several extra faceplates with lots of clamps & such.

"So far".. I downsized a nominal 8" (200 mm) off the HBX-360-BC for a pair of 7 1/4" (185 mm).. as the OEM built-in sliding chip/coolant shield ... and the mounting rail at the front edge of the cross were at-risk..

There will ALWAYS be work that simply needs some other, larger, lathe.

Or a kludge .. better done on the the milling machine?

If that chuck is good, and a good deal, do you have a mill that could swing it?

Is it worth grabbing as "trading material"?

I'd go for it, - especially if the $$ is right, gooduns are not easy to find or cheap when you do ..while of course paying attention to John Oders post.

IME, yes you can hold big work in smaller chucks (extended jaws etc etc) but once you use a big chuck on big heavy work, you won't want to go back.

I have a 15" 4 jaw I use on occasion on my 16" Monarch.

You can get into a no man's land due to chuck jaw extension. I had a Union 10" on the SB10L at the museum that worked great 99% of the time. There was one diameter (can't remember exactly now) but say it was 7-8", where the chuck jaws would hit the bed no matter if they were inside or out facing.

Doing a lot of maintenance work by repairing my customers production machinery I have chucks of all sizes. 3, 4 and 6 jaw chucks, some with set-true adjuster and others that are universal/independent combined. Diameter from 16" down to 4" with D1-6 back plates that will fit 12, 14" Hendey, 14" L&S plus 16" P&W. I have used large chucks that just about fit when required to be able to chuck work I had. One has to be very careful when jaws extend beyond the OD of the chuck body and are close to hitting the ways so that hand or arm is not dragged in. A shear point is created and will easily cut off body parts. Spindle should be put in neutral and rotated to insure nothing will impact since large diameter uses slow speed hence quite a bit of torque will cause catastrophic conditions if something stop rotation.
I don't see much of a problem using you 16" chuck as long as caution is used when the jaws extend beyond the OD of the chuck. Might look around for a 10" 3 jaw.
For larger work I use my 24" Hendey (26" max swing) with 20" 4 jaw chuck. Size of the jaws when out near max will impact the ways and carriage so I have to test the clearance with the carriage near the chuck.

I've got a Monarch CY. While I have a 12" Bison 4 jaw I usually use a 10" 4 jaw for preference.

IMO a 16" 4 jaw is too big but that's just me. I have a 16" face plate though so have another option.

If I can't grip it in the 12" Bison I'm not sure I want to bother with it in the lathe at all.

PDW

Froneck said:

For larger work I use my 24" Hendey (26" max swing) with 20" 4 jaw chuck.

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^^^ THIS ^^^

For common-sense. Is one of the exact same lathes I'd be wise to run anything I have that large on as well.

EG: If too big for my HBX-360-BC, (max clearance 400 mm / just shy of 16") click the "Send email to" under the "Froneck" PM login ID ....and ask you to quote it!

Really folks. If yah have "regular" need, tool for it, the machine to fit it easily as important as the workholding.

If it is once in a blue moon?

Run what yah got.

Call on anudderbrudder to run what HE has "got".

Not as if we was all Robinson Crusoe isolated, is it?

Thanks guys. I'm going to look for something smaller, 12 to 14 inches.

Simply put if you can buy the 16" chuck cheap, buy it. What most don't realize is that the newer lathes can't swing more than the rated size. A while ago I got a high precision job, bought at the time a New DoAll Lathe, found out later it was a Harrison. It was 15", max swing was 15.006"! Might be a bit of exaggeration but I doubt if I could get more than a piece of paper between 15" diameter and the ways! So I wouldn't worry about a 16" 4 jaw chuck on a 16" Monarch that will swing more than 18". But I would get a smaller chuck when it becomes available. I'm lucky, have a larger lathe but I have chucked items in the 24" Hendey where the jaws just cleared the ways. I just made sure I was no where near the jaws when running the lathe and waited until the chuck came to a complete stop before doing anything near the jaws. I was reminded to not do anything until the chuck completely stopped when I attempted to do something when the rotational speed slowed well below 1 RPM when the clutch was released. I have an E size Aloris tool post with 1-1/2 carbide tool holder and was attempting to do something, when the jaw came around it began to squeeze my finger between it and the tool holder, I was able to pull it out in time, the chuck continued to rotate almost 1/2 turn in about 1 minute before stopping! The weight of the chuck and the 16" X 36" steel bar added to the spindle and gearing has quite a bit of inertia. Thought it looked as if it was stopped it wasn't, from now on I'm sure it's stopped before doing anything! My finger is fine, squeeze was not much only slight pressure. Also large 4 jaw chucks might have T slots so they can be used as a face plate, my 20" has a T slot located between the jaws. It came with a allen cap screw that must be removed to put anything in the T slot so it will prevent what ever from flying out. I do have a 22" Face Plate as well as a few smaller chucks but the weight of the chuck makes changing it a bit of a task. However I have a 14" L&S model X with a 15" 4 jaw chuck it it all the time, it too has t slots. Yeah I'm lazy so having a lathe with with a 4 jaw chuck mounted all the time saves having to change the chuck but I can change it as all the lathes have D1-6 spindles (except the 24" is D1-8) and a pile of just about every size chuck available. Reason for all the chucks is for Jaw size.

I'd get it, if you ever want to use the max swing of the lathe. Chuck jaws are hanging pretty far out gripping at 16" piece with a 14". I'd feel much more comfortable with a 16" for very big work. There is a perfect one out in cali, but freight is prohibitive.

ClappedOutBport said:

I'd get it, if you ever want to use the max swing of the lathe. Chuck jaws are hanging pretty far out gripping at 16" piece with a 14". I'd feel much more comfortable with a 16" for very big work.

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I agree with you, 16" in a 14" chuck just just might not fit well. About
2" of each jaw will be out of the chuck, Jaw threads don't usually start until about an inch below the OD so the number of threads holding the jaws will be small so that the possibility of breaking the jaw threads is very probable. They are hard to find used but 4 jaw chucks with 2 piece jaws are good to have, I must have at least 10 four Jaw chucks but only one has 2 piece jaws. (12" chuck) Keep your eyes open for one of them.

Up until recently, lathe swing was rated as the largest faceplate that would clear the carriage wings. Modern swing rating is center to the ways.

Mike C. said:

Up until recently, lathe swing was rated as the largest faceplate that would clear the carriage wings. Modern swing rating is center to the ways.

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If that's the case, it makes sense as modern carriage wings are so short. However; I'm not sure it is. My Sidney will clear more than 16" to the carriage wings, and in fact I'm pretty certain the tailstock Vee way limits it to 18.5. My understanding is that it was the largest piece that could be practically chucked and turned.

O know the Cincinnati makers, LeBlond, L&S, American, Monarch and others used that rating method. Modern isn't even measured by the wings or faceplate, it's just straight up actual swing to the bed. Same concept as a 5hp "peak load" Lowe's air compressor that puts out 2cfm at 90psi.

It's hard to say how the older lathes were rated, some like monarch had the rating size as well as the actual size stamped on the Name Plate. I've owned lathes that the max swing did not come close to the wings on the carriage, I'm somewhat sure my 14" Hendey will swing the limit to the ways and not hit the carriage wings yet my P&W and L&S will hit the rear carriage wing however they are a slightly newer vintage. I currently don't have a Monarch but did have a few and if my memory is correct max swing was to the ways and carriage wings did not lessen the swing available. As to Modern lathes I mentioned the DoAll I had being 15", if measured it would have been 15.006".