#34 Jacobs chuck

[chucketn]

I was given a No34 Jacobs 1/2" capacity Drill Chuck. It has a 3/4" straight shank, is keyed, and has a knurled sleeve. Patent date is 1902. I cannot tell if the shank is integral or has a Jacobs taper into the chuck back. Looking in the jaw end it does not appear to have a screw securing the chuck to the shank. Can anyone tell me if the shank is integral?
I have searched for info on this chuck and have not found anything on it.

Chuck

 

[GailInNM]

Does this help any. The 34 series were all taper mount.
Gail in NM

 

[chucketn]

Thank you, Gail. Was hoping it was a Jacobs Taper mount. Now to find a J2 to R8 shank to use it on my mill and the Wedges to remove it.

Chuck

 

[GailInNM]

Note that it was made with JT6 and JT33 taper as well as the JT2. The JT33 and JT33C was very common in the early 1960's on the heavier Craftsman drill presses so you may want to remove the existing shank before searching for your R8 adapter. Most of the Jacobs drill chucks will have the taper marked on them some where.
Gail in NM

 

[chucketn]

Note that it was made with JT6 and JT33 taper as well as the JT2. The JT33 and JT33C was very common in the early 1960's on the heavier Craftsman drill presses so you may want to remove the existing shank before searching for your R8 adapter. Most of the Jacobs drill chucks will have the taper marked on them some where.
Gail in NM

This is the only drill chuck of any brand I have ever seen that did not have the taper marked on it. The particular chuck has a Weldon style shank, 3/4" in dia., with 2 flats on it. The flats have marks from set screws. I do have a 3/4" R8 collet I can use it in. I may just mount it that way and check run out. Has to be better than the one I have with R8 shank!

Chuck

 

[GailInNM]

Got me Chuck.
Like you, every taper mount Jacobs Chuck I have ever seen has had the taper marked on the Chuck somewhere.

I pulled up the Jacobs catalog and it lists the number 34 under the category of taper mounted chucks.

Since you mentioned wedges, I assume that there is space between the arbor and the Chuck where they can be used. Just for fun, I looked up the specs for the three tapers listed for the diameter of the taper where it enters the Chuck. Here is what I found.

JT2 0.559
JT33 0.624
JT6 0.676

You might measure in the gap where the wedges would go and see if where the arbor enters the Chuck is close to one of those. If so, it probably is a taper mount. If not then I am out of ideas.

Have fun.
Gail in NM

 

[chucketn]

Thanks again, Gail. I will measure the arbor today.
I can use the chuck as it is, but thinking it may be better on an R8 shank.
I will check with my buddy that gave it to me and see if he has wedges. He's coming to visit tomorrow.
How are you finding all the info on the No 34? I search and find some references from Jacobs, but not what you are providing. Do you have an old catalog or something?
And, what pictures I've found show a groved sleeve, mine is knurled.

Chuck

 

[GailInNM]

Chuck,
I had not seen any Jacobs keyed chucks with a knurled sleeve either, so I did a quick search and came up with this. I think this is the Chuck you have. These images are fpr one for sale currently on eBay. It has a Morris taper shank, but you can see the space between the Chuck and the Arbor for wedges.

The information I gave you earlier came from the current Jacobs catalog at: http://www.jacobschuck.com/
If you click on catalog it will give you more information about Jacobs chucks than you ever wanted to know.

 

[chucketn]

I saw that e-bay chuck. Yes, that looks like the one I have. I will measure the current arbor today and take a picture of it. I have asked my tool maker buddy if he happens to have wedges.

Chuck

 

[chucketn]

I measured the diameter of the shank at the back of the chuck where the wedges would go at .624". Guess that indicates a JT33.
Pictures attached.
Chuck

 

[GailInNM]

Chuck,
If you are going to pull the arbor, I suggest that you put a few drops of penetrating oil, Liquid Wrench or similar, on the joint now so it has some time to soak in. As old as it is it may be stuck on pretty good.
Gail in NM

 

[Chiptosser]

That one is definitelyan, Old Timer!
I have all the different sizes of the wedges that is sold for removing the arbors.
Don't waste your money! Besides, you don't have a shoulder for the wedges to catch or shoulder on.
I would check the jaws for wear, look to see if there are steps or taper wear. The jaws should close down to hold at lest a 1/16" drill.

If they don't you'll e just wasting your time changing the shank. I repair the chucks at work, all the way up the the monster Ball bearing unit on the #5 shanks.
If you want to mess with it, Cut the shank off, chuck up a 1/2" dowel and drill the tapered portion out of the chuck .

All the new Jacobs, are now made in China, and they are not holding up. The chuck keys are ps, rounding the teeth off the sleeve
You can tell the new chucks from the old ones, by looking for the stenciled I.D. on the back near the mounting hole.

Good Luck

 

[Chiptosser]

Let me clarify my last comment.
Whom ever is having them made in China, there has been some slight changes made in the dimensions of the sleeve. This is on the tooth area. The chuck key is made of a powdered material.
This combination is not, making for a good combination in heavy daily use, for a machine shop.