I bought an adjustable 3 Jaw chuck

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AllenH59
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Location: Prince George BC Canada

I bought an adjustable 3 Jaw chuck

Post by AllenH59 »

http://turnochucks.com/as-type.html

I bought a 10 " one of these chucks. My lathe has a threaded spindle, so I needed to make a backing plate. I made a hub and had a pressure welder buddy weld a piece of 1" plate to it. I turned it to to fit, and drilled the mounting holes on the mill by putting the backing plate in in the chuck on the rotary table, it is rewarding when bolt holes exactly line up.

This chuck has 3 adjusting screws, which advance in the direction of the individual jaw. The other adjusting screws have to be loose enough to allow the movement. It took about 15 min to catch on to centering, and after that it was no problem to be within .001" on the dial indicator. This chuck is heavy, maybe 85 pounds with the backing plate. As a test I took a piece of 1.75 material, 6" long, and turned about 2 inches at one end eccentric to the diameter of the shaft. When it was round I put the dial on it and confirmed it was round. I turned it around in the chuck, and centered on the diameter I had turned. I then turned the eccentric off the long end, and stopped at the same setting that I had stopped at coming the other way. There was no misalignment, or if there was I was unable to detect it. This chuck is about $350 US and freight is about $275 US, it would be less shipped to the USA, as that was fedex to Canada. I bought it there as this is was the manufacturer of the chucks that originally came with my lathe, and I wanted to add one to the set. Now I have a Chinese 5C collet holder, a 6" 3 jaw, a 10" 3 jaw and an 8" 4 jaw and a chinese 12" 4 jaw.. Making backing plates has become a hobby.
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Harold_V
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Re: I bought an adjustable 3 Jaw chuck

Post by Harold_V »

I would hope to see that at least one of your universal chucks has master jaws, so you can run soft jaws. That feature, alone, will duplicate the ability to eliminate eccentricity, with the added benefit of being able to tailor jaws to given configurations. That ability provides for holding objects that can be difficult to install, like thin plates (discs), registering them not only in regards to concentricity, but perpendicularity as well.

One of the excellent features of soft jaws is their ability to grip objects without doing any damage. Fine finishes can be gripped without issue, and thin walled items can be gripped without distortion, assuming one uses pie jaws. Soft jaws are truly the magic bullet for holding lathe work.

H
Wise people talk because they have something to say. Fools talk because they have to say something.
AllenH59
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Re: I bought an adjustable 3 Jaw chuck

Post by AllenH59 »

No Harold, I do not have soft jaws, yes I guess that is the next one. I have made the copper jaw covers to protect my work, and fitted them to the 4 jaw chucks.. I do not have anything I can bore.
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Harold_V
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Re: I bought an adjustable 3 Jaw chuck

Post by Harold_V »

I used to use my lathe for gain. It was purchased for that purpose. Aside from a Hardinge-Sjogren collet chuck, I have but two chucks for the machine. One is a 10" four jaw, which sees but occasional use, the other an 8" with master jaws. It is the most used of the two chucks.

I rarely use "factory" jaws, although there are times when they work adequately. I keep a set of through-bored jaws in the chuck, and change them when required. The jaws that are in use provide a much better grip, and they run truer than the factory jaws.

Note that I am not intimidated by four jaw use. I'm perfectly comfortable with adjusting them to exacting conditions. It's just that it's a waste of time unless it's needed, as properly prepared soft jaws eliminate any fiddling. If there's more than one item to be handled, there's no way a four jaw can compete, plus one has the added benefit of being able to R/R pieces without losing registration. Further, when producing more than one off, the benefits of soft jaws are lost on a four jaw, as it's virtually impossible to install pieces in the same place, so stops or DRO settings in the longitudinal orientation are lost. That isn't true with soft jaws that are machined with a shoulder.

The money you spent on an adjustable chuck would have been better spent on one with master jaws. You would have had no need for the adjustment. Just sayin', mind you! :wink:

H
Wise people talk because they have something to say. Fools talk because they have to say something.
pete
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Re: I bought an adjustable 3 Jaw chuck

Post by pete »

At 85 lbs. I hope you know about making a wooden chuck cradle Allen. Basically a wooden assembly of glued and screwed together dry construction grade (fir would be my choice) that indexes off one of the way Vee's, fit's at least partially between the bed opening of the two ways for guiding purposes, and is radiused to fit the chuck diameter. It also needs that radius cut so when the chuck is loaded into it that chuck is already at the correct elevation to thread it onto the spindle. There a huge help since the carriage can be moved back, drop the cradle into place on the ways, load the chuck and then simply slide it up to the spindle. It's not "if" your going to drop a heavy chuck and damage the ways, it's only how long until you do. There also a real back saver since your not trying to hold that heavy chuck in position while threading it onto the spindle. With lighter chucks I just use a piece of plywood to protect the ways, but at 85 lbs I'd sure want something to support the chuck while it was being changed.
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BadDog
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Re: I bought an adjustable 3 Jaw chuck

Post by BadDog »

I've got some big chucks, and yes, a cradle is pretty much mandatory to protect lathe, chuck, and operator. I made mine with scrap 2x4s or 2x6s for big tippy 12" and 15" 4 jaws. Bottom was notched to fit the v-way. Built up on top of that with whatever handy (1x, plywood, etc) to take up most of the space. I then took 2 short drops and cut a 45 miter on them. One slid up in front, and one behind to take up the space with chuck installed so the chuck is sorta setting in a shallow v-block affair. Screw those in place, and it's near perfect for loading/unloading the chuck. Once the pins clear, if I can't lift it safely, it's ready to be lifted with an appropriate apparatus (I use a "sky crane"). My lathe has a 60" bed, which still hasn't been needed in full after ~10+ years. So, I store my big chucks at the tail end behind the tail stock, all mounted on their custom fitted saddles and ready should I need them. Not nearly as pretty as some I've seen with nice round pockets and stained/varnished, but that's never been my style for show tools...
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tim9lives
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Re: I bought an adjustable 3 Jaw chuck

Post by tim9lives »

Allen., I also just purchased a 3 jaw Rohm with the adjustable jaws. It’s a very nice chuck with precision fitting jaws. Anyway I totally agree with you that it’s a bit of a learning process to adjust it. That said , I like it. FWIW, soft jaws are also worthwhile. Anyway, tooling is a never ending odyssey with this hobby.
SteveM
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Re: I bought an adjustable 3 Jaw chuck

Post by SteveM »

AllenH59 wrote: Sun Oct 04, 2020 12:40 pm No Harold, I do not have soft jaws, yes I guess that is the next one. I have made the copper jaw covers to protect my work, and fitted them to the 4 jaw chucks.. I do not have anything I can bore.
usshoptools.com

best price on soft jaws.

Steve
Glenn Brooks
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Re: I bought an adjustable 3 Jaw chuck

Post by Glenn Brooks »

Apparently South Bend used to sell 3 jaw adjustable chucks with their lathes in the early days. Iam just finishing up the cleanup and return to service of my old 1925 SB9. Today just looking at the chuck, which is a 3 jaw adjustable. Original to the lathe, so far as I know. Seems like a pretty cool feature.
0602EB30-5250-428A-AF49-D85AB541CBF9.jpeg
Interesting to know somebody is still making them...

Glenn
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4gsr
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Re: I bought an adjustable 3 Jaw chuck

Post by 4gsr »

That's a unique looking chuck for a 3-jaw. I've seen 4-jaw universal chucks with that feature and have a couple of 3-jaw chucks with the adjustment between the back plate and chuck.
Ken
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Bill Shields
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Re: I bought an adjustable 3 Jaw chuck

Post by Bill Shields »

I have a 12" 6 jaw with this adjustment feature. Pretty sure it is a Buck.

My father in law used it to bore couplings for a PT shop back in the 80's (sounds so long ago)

My lifting cradle is an eye bolt and a chain fall over the lathe on an I beam. the cradles are nice.. but I still have to get it down to the floor on the dolly.
Too many things going on to bother listing them.
shootnride
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Re: I bought an adjustable 3 Jaw chuck

Post by shootnride »

Glenn Brooks wrote: Fri Oct 23, 2020 11:25 pm Apparently South Bend used to sell 3 jaw adjustable chucks with their lathes in the early days. Iam just finishing up the cleanup and return to service of my old 1925 SB9. Today just looking at the chuck, which is a 3 jaw adjustable. Original to the lathe, so far as I know. Seems like a pretty cool feature.

0602EB30-5250-428A-AF49-D85AB541CBF9.jpeg

Interesting to know somebody is still making them...

Glenn
I believe that your chuck is a different style from what the OP purchased. Yours is a combination independent/scroll chuck, whereas the OP's is a Set-Tru style chuck. The Set-Tru style just allows for a small adjustment of the entire chuck body on the backing plate. The combination style chucks allow for independent adjustment of each chuck jaw. I have one of the combination chucks in a 4-jaw and a Set-Tru style 6-jaw. Both are nice features, but the independent style allows for MUCH more adjustablilty and and can be used to mount odd shaped work pieces.

I was reading the information about the OP's new chuck in the link that he posted and there's something that either I just don't understand or there is a typo in that document. It states that " these chucks are adjustable up to 0.005mm". That's only 0.0002 inch. They must have more adjustability than that.
Ted
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