Jacobs 33 chuck. Some questions in general

[2stroke1971]

I am working on my 2nd Craftsman King Seeley drill press, tearing it down at this point. It has a #33 jacobs chuck on it.

Like everything these days, there are contradicting answers out there.


The knurled collar with the pin holes suggest it was one that would have spun off, having been threaded on. (My other Craftsman, 1947, which is in use, has a jacobs 7A, which I understand is a taper unit.)

I tried, not too hard, to unthread the chuck. I figured it would be easier to manage after taking the rest of it apart, so I went ahead and drove the drive shaft out of the quill. (rawhide mallet and a brass drift after it went flush with the quill)

In the process of those taps, the chuck came off. The end of the shaft I was left with had a taper. That knurled collar still on the drive shaft. When I got the chuck, it had a roll pin sticking out of it diagonally. I guess it wasnt in enough to secure the chuck.

So this has a taper. And there are two holes drilled diagonally thru the chuck that correspond with a hole in the taper. (only one hole in the taper though)
And yet it has that knurled collar, and the holes for the removal tool.
I will attach a pic.

There is also a dowel pin securing whats left on the shaft. (I could drill it out I suppose, I saw someone had done that before)

So, my chuck is off...but what the heck...a 33 with a taper? If you look up removal of an old jacobs, you will INVARIABLY get half the people telling you to get wedges, and the other half saying "O well if you have the knurled collar with the holes, you just unthread it" There are no threads on the chuck or on whats left on the drive shaft.

The taper is damaged from the chuck spinning on it at some point in its life.

I want to get the rest of the items off the end of the drive shaft and go with something else. Not sure what ill be looking at when it all comes off.

Any comments would be appreciated.

 

[2stroke1971]

I guess ultimately what I need to know is when I go to replace this chuck...what will I be looking for? something with a "jacobs taper"? Is that what Ive got here?

And, the taper I have is damaged....I suppose it and the rest will come off after drilling out that dowel...is there a way to replace that part of it with something new?

 

[Provincial]

If your taper is scored from the chuck spinning on it, you need to replace the spindle. You will never get a chuck to hold in place and/or run true with a damaged taper.

If there are no threads on the old spindle, it was designed to not use a collar. The collar was introduced to hold the chuck in place when using a tool with an intermittent cut, like a shaper bit. Probably the old chuck came loose and damaged the taper, causing a prior owner to buy a new chuck from Sears, who sold him the then-current design with the collar.

Check with Frank Lee to see if he has a spindle available.

 

[larry_g]

I'm going disagree with my learned friend above. I have successfully re-cut the taper on an old drill press spindle. It takes a lathe and a bit of fiddling to get it right but it can be done.

lg
no neat sig line

 

[FrankLee]

Sorry, I don’t have any good spare drive shafts.

 

[2stroke1971]

I did drill the dowel pin out. It didn't damage the collar or the shaft in the least. errr I mean the thrust collar or the...umm...what was it again? oh... spindle. <groan>

Got in about 1/4 inch, and the pin started spinning on the bit and I pulled it out clean. I do this sort of thing for a living. (not work on old drill presses, just machines in general)
I suppose that I did not have to remove it, i thought it was part of the chuck so to speak, as in if I were to replace the chuck etc.... eh no loss.

As for recutting the taper, I also thought of that. I have a nice lathe at work that I use a lot. Get the angle correct and it should be alright. If I wind up with a small portion at the bottom that will then be too narrow, I can face it off.

There is not an ID plate on this unit. My other one has a metal tag on the base near the post. Pole. Vertical pipe that comes out of the base.

I am thinking that the roll pin thru the edges of the chuck, down into the taper area is NOT original, but something a previous owner did after the chuck spun. No diagram I see for any craftsman around that era has anything like that. So, we'll see how it goes. Ill give re-cutting the taper a go if I get the chance later. I put the chuck in an ultra sonic cleaner full of a mild caustic for just a bit, then rinsed, dried, then soaked it in machine oil. It seems to be working a little better, but I think Im still going to replace it.

We'll see how it shakes out.

Thanks for the replies!

having trouble with the pics here, will try and fix them when I get home later.

 

[2stroke1971]

I did some measuring, and it seems I have a 2 1/2 size chuck and a size 2 spindle.

Taper in chuck runs 1 inch deep, spindle taper is 1/2 inch. Large end measurements jive as well for this being a mismatched pair. Probably why the diagonal roll pins were there, this chuck wasn’t proper to begin with when a previous owner put it on....doesn’t seat very far, explains why it spun and why someone put a pin in it. &#55357;&#56900;

 

[Whitworth]

So someone force-fit a mismatched chuck onto the spindle. I've seen some chucks that have been welded on.
You'll need a new spindle.