Newbie getting in over my head?

All discussion about lathes including but not limited to: South Bend, Hardinge, Logan, Monarch, Clausing and other HSM lathes, including imports

Moderators: GlennW, Harold_V

nessism
Posts: 52
Joined: Sun Oct 23, 2022 10:54 pm

Re: Newbie getting in over my head?

Post by nessism »

rmac wrote: Fri Feb 24, 2023 11:19 am
nessism wrote: Thu Feb 23, 2023 9:40 pm And learned tonight, that the 3 jaw chuck is jacked up and doesn't close properly.
Can you give more detail here? What exactly do you mean by "doesn't close properly"?
Sorry for the late reply...

The jaws bind up as they reach the last 1/2" of travel, before they touch each other, closing down. I found a nasty burr on one of the jaw scroll teeth, and filed it down, which helped, but the jaw action is still kind of rough. The jaws themselves don't slide particularly smoothly in the grooves in the chuck body. I used some lapping compound in an attempt to mate the parts better, and that helped, but the action is not particularly smooth, especially when the jaws are getting close to the end of their travel.
User avatar
rmac
Posts: 787
Joined: Tue Jun 26, 2012 12:48 am
Location: Phoenix, Arizona

Re: Newbie getting in over my head?

Post by rmac »

nessism wrote: The jaws bind up as they reach the last 1/2" of travel, before they touch each other, closing down.
Thanks for that! I was thinking maybe if you were a complete newbie, you might not understand how the jaws must be installed in 1-2-3 order when you're assembling the chuck. But that's obviously not what's going on here.

On my four jaw chuck, the jaws and the slots they go in are not match marked like they are on my three-jaw chuck. If everything was perfect, I suppose that you could put any of the jaws in any of the slots. On my chuck, however, there is only one arrangement that works without a bit of roughness/binding on at least one of the jaws. Again, that's probably not what's happening with your chuck because the slots and jaws are probably matched.

-- Russell Mac
User avatar
Bill Shields
Posts: 10464
Joined: Fri Dec 21, 2007 4:57 am
Location: 39.367, -75.765
Contact:

Re: Newbie getting in over my head?

Post by Bill Shields »

Probably full of chips and dried up cutting oil in the scroll.

Take apart and give good scrubbing
Too many things going on to bother listing them.
nessism
Posts: 52
Joined: Sun Oct 23, 2022 10:54 pm

Re: Newbie getting in over my head?

Post by nessism »

Bill Shields wrote: Sat Mar 04, 2023 12:00 pm Probably full of chips and dried up cutting oil in the scroll.

Take apart and give good scrubbing
Already did that. That's how I found the burr.

The jaws are numbered, but the chuck body isn't. After trial fitting each jaw in each slot, they only fit one way, and they don't slide super smooth. The scroll gear doesn't rotate super smooth either. I dressed all the edges and it helped, but it needs more work...or to be thrown in the recycling bin. I'm leaning towards the later. :twisted:
User avatar
Bill Shields
Posts: 10464
Joined: Fri Dec 21, 2007 4:57 am
Location: 39.367, -75.765
Contact:

Re: Newbie getting in over my head?

Post by Bill Shields »

There are always uses for old ratty chucks...even if it is to hold something for silver soldering, or bolt it down on the milling table to hold something round.

Unless you are really tight on space, I would keep it around, even if you never use it in a lathe.

One thing I learned about lathes early on...a person often spends as much $ on tools and accessories as the machine.

$ of a good chuck is $ well spent.

A cheap chuck is $ down the toilet.
Too many things going on to bother listing them.
nessism
Posts: 52
Joined: Sun Oct 23, 2022 10:54 pm

Re: Newbie getting in over my head?

Post by nessism »

Bought this. Going to have to make a backplate. One issue: it's 165mm diameter, which is 6.5", and the largest backplate for similar size I've found is 6.3". I don't want the backplate inset from the body, so I may have to hack down an 8"'er. That will be a nice first real lathe project. :idea:
JN06T.jpg
JN06T.jpg (159.37 KiB) Viewed 3955 times
User avatar
Bill Shields
Posts: 10464
Joined: Fri Dec 21, 2007 4:57 am
Location: 39.367, -75.765
Contact:

Re: Newbie getting in over my head?

Post by Bill Shields »

They make good stuff...including entire machines
Too many things going on to bother listing them.
User avatar
Harold_V
Posts: 20232
Joined: Fri Dec 20, 2002 11:02 pm
Location: Onalaska, WA USA

Re: Newbie getting in over my head?

Post by Harold_V »

nessism wrote: Sat Mar 04, 2023 7:14 pm Bought this.

A good choice. You'll be able to use soft jaws.

H
Wise people talk because they have something to say. Fools talk because they have to say something.
nessism
Posts: 52
Joined: Sun Oct 23, 2022 10:54 pm

Re: Newbie getting in over my head?

Post by nessism »

What say ye on the back plate? Live with the smaller jobby, or hack down the larger one? I'm leaning toward the later, unless someone talks me out of it.
User avatar
Harold_V
Posts: 20232
Joined: Fri Dec 20, 2002 11:02 pm
Location: Onalaska, WA USA

Re: Newbie getting in over my head?

Post by Harold_V »

Assuming there's a counterbore in the chuck that would center the too small back plate and allow for full holes that hold it in place, I don't really see much of a problem. A small radius filed on the sharp corner of the chuck (while it's turning slowly) would eliminate a sharp corner so it would be comfortable to handle.

I'm assuming that the proper back plate would be the same diameter of the chuck and mount flush with the OD of the chuck and have a spigot which locates the backing plate in the chuck. The purpose of the spigot (that should fit the counterbore with a snug slip fit) is to ensure that the chuck remains on the centerline.

A picture of the back side of the chuck might change my mind. It all depends on if the mounting bolts won't create any exposed sharp edges.

H
Wise people talk because they have something to say. Fools talk because they have to say something.
nessism
Posts: 52
Joined: Sun Oct 23, 2022 10:54 pm

Re: Newbie getting in over my head?

Post by nessism »

The bolt holes, if using a 6.25" backplate, would be quite close to the edge of the backplate.

chuck.jpg
chuck.jpg (373.73 KiB) Viewed 3768 times
nessism
Posts: 52
Joined: Sun Oct 23, 2022 10:54 pm

Re: Newbie getting in over my head?

Post by nessism »

I took apart the Kitagawa chuck and all I can say is WOW! It's a real jewel on the inside. There is virtually no discernible wear, other than the black oxide coating on the pinions being slightly worn in places. I was concerned with buying a used chuck, but this thing has only seen minimal usage at best.

I'm tempted to do a light bead blasting on the outside, to remove the gray patina. We'll see. I still need to get a back plate, of course. I'm leaning towards a "South Bend" (Grizzly) 8" "thick" D1-4 unit, and chopping it down to size.
Post Reply