I bought an adjustable 3 Jaw chuck

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SteveM
Posts: 7763
Joined: Mon Jun 27, 2005 6:18 pm
Location: Wisconsin

Re: I bought an adjustable 3 Jaw chuck

Post by SteveM »

shootnride wrote: Thu Feb 04, 2021 10:48 amI 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
I think they are saying that you can get it to within 0.0002"

Steve
shootnride
Posts: 298
Joined: Tue Jun 05, 2012 12:31 am
Location: Sacramento, Ca.

Re: I bought an adjustable 3 Jaw chuck

Post by shootnride »

That makes more sense.
Ted
Some people raise the IQ of the room when they enter.........others when they leave.
AllenH59
Posts: 479
Joined: Wed Mar 16, 2011 1:26 pm
Location: Prince George BC Canada

Re: I bought an adjustable 3 Jaw chuck

Post by AllenH59 »

I have had my chuck apart, there was a small chip made it into the works, and I could feel it as I tightened the scroll plate, I wanted to have a look inside, and after paying for it I was eager to keep it working. Here is how it works.

I cannot see how to attach or insert a drawing, so I will do it in words.

Firstly the back of the chuck bolts to the backing plate I made, with three 12mm bolts. This is really just a backing plate for the mechanism.


This is attached to the mechanism with three 8mm Allen Head bolts, which are not very tight, but are countersunk to be below the surface that rides against the backing plate I made. So there is movement between the backing plate of the chuck (Not the one I made) and the main body.

The backing plate of the chuck has a very solid looking hub protruding into the center of the body, with three depressions in it. These depressions are aligned to the adjustment screws, and this is how the chuck is adjusted. There is a normal scroll plate in front of this.

The adjustment screws are threaded through the main body, and have ball bearing rollers pressed into the end of the rollers, and are at an angle, to force the main body against the backing plate and achieve adjustment.

I have done quite a bit of work with this chuck since I got it last fall, and it is extremely easy to center, and if something is truly round, it is centered close enough that a .001" dial indicator does not see the error. At first I thought that it was not touching, or stuck or such the like. The centering technique is intuitive. I have turned pieces around, with a slight difference in diameter that the diameter originally centered at, and it was still way under .001" movement on the dial.

It is a treasure in my shop. The only down sides are.1. It is heavy.. I had to build a wooden block just the right height for installing and removing it, my lathe has a threaded spindle, and something like 80 lbs for a 10" chuck is a problem for my aging frame. It is so heavy that my lathe does not want to start it in it's two highest speeds, which are 800 and 1400 RPM.. yes, my lathe is under powered for that. 2.. It is long, with the backing plate I made, and backing plate on the chuck it is about 1-1/2" longer than my 12" 4 jaw. This is a benefit in some ways, such as having the deep 75mm hole behind the jaws, but it effectively shortens the length of the bed that much. My lathe is 16"x48", and that was nearly a problem on one job. I will be buying a smaller one with six jaws when I find myself needing to have a new tool in my shop. I am as much a tool collector as a hobby machinist.
johnfreese
Posts: 219
Joined: Thu Jan 21, 2016 2:10 am

Re: I bought an adjustable 3 Jaw chuck

Post by johnfreese »

I have a 6.5" Yuasa with 3 adjusting screws. Getting work dialed in with 3 screws can be very frustrating.
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4gsr
Posts: 30
Joined: Fri Jan 08, 2010 6:45 pm
Location: Victoria, TX

Re: I bought an adjustable 3 Jaw chuck

Post by 4gsr »

Yeah, I bet that is a bear to true up. I have a 8" Yuassa super spacer with a adjustable 3-jaw chuck, I'm almost certain it has 4 adjusting screws, I'll have to look. Have a 6-jaw Bison chuck that has 4 adjusting screws that are not spaced at 90 degrees apart, it's spaced like 40-50-40-50 degrees. It gets a little awkward to adjust at times. Ken
Ken
RSG
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Joined: Fri Feb 04, 2011 9:59 am
Location: Ontario, Canada

Re: I bought an adjustable 3 Jaw chuck

Post by RSG »

Harold_V wrote: Sun Oct 04, 2020 1:59 am 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.

Soft jaws are truly the magic bullet for holding lathe work.

H
Thumbs up here! I have three chucks dedicated to them....

AllenH59, sounds like you picked up a nice chuck, I couldn't help but notice though how much you paid for shipping, that's insane....
Vision is not seeing things as they are, but as they will be.
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