How not to service a Jacobs chuck

[mattthemuppet2]

1. Don't do it late at night when you want to do something else

2. Don't do no. 1 after already fixing a different Jacobs chuck, as that will make you think you somehow know what you're doing

3. Don't use PVC pipe as a standoff to press the sleeve off as that is very very stupid and you will end up with a chuck inside a PVC pipe

4. Just stop there, further attempts will just end up in tears/ swearing/ both

5. If you ignore 4., for goodness sake don't keep cranking on the press handle when it won't come out all the way. It's probably come out cocked and if you keep pressing you'll just bugger it up.

6. If, after hours of work you managed to fix all the screw ups you've just caused, you manage to get it back together and working well DON'T GIVE IT ANOTHER LITTLE TWEEK ON THE PRESS as it will then no longer work and you'll have to take it apart again
It's now fixed and opens/ closes freely other than a couple of slightly tight spots. If I'd known then what I know now, I would have happily put up with it being a bit sticky..

 

[12bolts]

So what are you doing about the cracks in the casing?

Cheers Phil

 

[mattthemuppet2]

pretending it doesn't exist

I'll chuck up the truest bit of rod I can find later if I can grab some garage hours and see if the runout is reasonable (0.005?). If it is, then I'll leave it as is. If not, I'll have to wait for payday and get a replacement.

 

[Chucketn]

Matt, I have a very old Jacobs chuck, I believe it's a 1A, that was in my Dad's Kennedy. It has an obvious weld repair to the outer sleve. It opens and closes a dream and when mounted on it's threaded arbor, has .0005 runout. I wonder if Dad learned the same lesson you just described, and a friend that was a good welder helped him out?

Chuck

 

[mattthemuppet2]

could be. I can't logically see a way in which an out-of-round sleeve at the taper end would affect accuracy, so hopefully it's still fine. Didn't get a chance to test it last night as I was working and I think I'm making grape juice tonight..

 

[middle.road]

pretending it doesn't exist

I'll chuck up the truest bit of rod I can find later if I can grab some garage hours and see if the runout is reasonable (0.005?). If it is, then I'll leave it as is. If not, I'll have to wait for payday and get a replacement.

Well, I'm thinking I can send you mine for repair, since you now have the experience. :biggrin:
I've got a No.34 still in a ziploc from when I attempted repairs to it sometime in the late 90's, and a couple of 14N's that need a look at.

_Dan

 

[mattthemuppet2]

Well, I'm thinking I can send you mine for repair, since you now have the experience. :biggrin:
I've got a No.34 still in a ziploc from when I attempted repairs to it sometime in the late 90's, and a couple of 14N's that need a look at.

_Dan

one learns by doing, right? I'd be happy to have a crack at 'em, but you may have to wait a similar amount of time to get them back again The 2 other ones I did were rescues from an eBay auction - $12 for 3 chucks, one of which has been fixed and working on my lathe for at least a year and the other is waiting for me to make a new arbor for it.

 

[Pat of TN]

I feel like I've read this somewhere else. Hehe.You gave it a good shot! At least it most likely won't affect anything important. I went through something similar today. Nothing specifically related, but the upshot of this is - when you start to get tired, or frustrated, it's time to quit for a little while. Like after breaking a 4-40 tap.

 

[george wilson]

Matt,do be careful with that chuck. Those special Jacobs with the safety collar are rather rare,and cost a good bit if you buy them new. It might cost more than your drill press did.

And now,Jacobs are made in China. The new ones might not be very good.

I am wondering if it would be possible to take a SIMILAR 1/2" Jacobs chuck without the collar,and just fit your collar parts to it? I have no idea if the bodies would be the same,but just without the collar.

Now that you have the collet chuck though,it is not really a necessity to have the locking collar on your chuck. You shouldn't be putting sideways pressure on it to make it come loose from the #33 taper. You could just get a regular 1/2" chuck that is more common,with the 33 taper hole in the top,and use that,if worse comes to worse. And,try to buy an old MADE IN USA Jacobs in good shape. I can't advise buying a Chinese Jacobs. I just do not know if they are good or not. Perhaps Jacobs has them made to the proper tolerances,and of GOOD metal. I have no idea.

 

[mattthemuppet2]

I feel like I've read this somewhere else. Hehe.You gave it a good shot! At least it most likely won't affect anything important. I went through something similar today. Nothing specifically related, but the upshot of this is - when you start to get tired, or frustrated, it's time to quit for a little while. Like after breaking a 4-40 tap.

agree with you 100%! I'm getting better at realising when I should stop, but sheer cussedness sometimes gets in the way.

Matt,do be careful with that chuck. Those special Jacobs with the safety collar are rather rare,and cost a good bit if you buy them new. It might cost more than your drill press did.

And now,Jacobs are made in China. The new ones might not be very good.

I am wondering if it would be possible to take a SIMILAR 1/2" Jacobs chuck without the collar,and just fit your collar parts to it? I have no idea if the bodies would be the same,but just without the collar.

Now that you have the collet chuck though,it is not really a necessity to have the locking collar on your chuck. You shouldn't be putting sideways pressure on it to make it come loose from the #33 taper. You could just get a regular 1/2" chuck that is more common,with the 33 taper hole in the top,and use that,if worse comes to worse. And,try to buy an old MADE IN USA Jacobs in good shape. I can't advise buying a Chinese Jacobs. I just do not know if they are good or not. Perhaps Jacobs has them made to the proper tolerances,and of GOOD metal. I have no idea.

It looks like a safety collar chuck, but it's actually a normal chuck that has a separate release collar threaded on to the spindle above it. Doesn't do anything to hold the chuck on, but a quick twist (now) pops it off for when I need to put that collet chuck on. Speaking of which, I used 3 different end mills and 2 different collets in it last night