Drill Press chuck flustration

[BFBOB]

I'm replacing the chuck on my Rockwell 15-081 15" 4-speed floor drill press - or at least I will be if I can get the old one off! By the way, thanks to 454ragtop for selling me a brand new one very reasonably.
So, knowing it was on a JT33 spindle, I put the old worn out chuck key in the old worn out chuck and beat on it with a hammer (gently) When that didn't work, I removed the spindle, figuring after 30 years in might be good to have a look at the bearings anyway. Indeed, the lower one is pretty rough.
Anyway, there was no wedge slot in the spindle; evidently, the taper is just ground on the end of the spindle.
So, when all else fails, RTFM. The manual said to beat on it with a hammer. Oh, and a brass drift. Or "use a wedge" Just that, not what surfaces are safe to wedge against, no illustration, nothing.
With the spindle out, there was plenty of room to get behind the chuck and beat on the top surface. I used my brass hammer as a drift and beat on it with a BFH. Well, more like an 8 oz. BPH. Still no dice.
So, I took a look inside the chuck and found what is pictured below. It looks to me like a screw! I know threaded chucks have LH screws to hold them, but why would a taper mount chuck need one??
I'd sure appreciate it if I could tap into the wisdom of one or more of you gurus and figure out where to go from here.
The chuck is toast, but I don't want to start really hitting it hard for fear of bending the spindle.
Thanks for any and all suggestions!

 

[Milton Shaw]

Any side pressure while drilling could dislodge the chuck with just a taper holding it on. The screw is an attempt at a safety to keep the chuck from coming loose on side pressure, such as using a sanding drum, or router bit in the chuck.

 

[yaidunno]

I dont know how much room is between the back side of the chuck and the face of the spindle. But these should help your situation. A spacer might have to be made if necessary.

http://www.mscdirect.com/product/08..._sJXegN7a0_PLA__15557577904_c_S&026=-99&025=c

Verify proper size of wedges with your setup.

 

[BFBOB]

Thanks, Milton. That makes sense, but there's no mention of it in the manual! The screw has been beaten up by drill bits, but I can actually see it better in the picture than in person. It's hard to see, looks like it's maybe a Phillips; I thought at first it might be square, but it's smaller than a #1S bit. I probed with an Allen wrench, and the two closest sizes either don't go in at all, or go in and spin freely. Torx? Should it be LH? I'm thinking on a non-threaded chuck it would be RH.

Thanks, yaidunno, very clever wedges. I guess the manual assumed the user should know there are purpose-built wedges and that's what they were talking about! I can make some easily enough.

 

[bisley45]

If it looks like this one .. you need these.. http://www.mcmaster.com/#drill-chuck-removal-wedges/=pr652s

 

[rsanter]

There may be no screw at all. It could be the center of the end of the spindle.
Some of them are made such that the chuck has a through hole so you can put a punch in there and knock the spindle out of the chuck by supporting the chuck from the back side.
However, the wedges are the best way

Bob

 

[BFBOB]

Weeelllll, I probed around in that screw oh, so gently and discovered that is indeed a screw and a Torx at that. T15 to be exact. I got the appropriate driver bit and tried gently loosening it. Not knowing for sure whether it's LH or RH, I alternated both directions, slowly increasing the torque. Yup, you guessed it. Snapped it off in the screw. Tapping to dislodge it nogo.

I wonder if new spindles are still available.

 

[yaidunno]

No need to give up on it yet. Did the head of the screw break off? If so, your in the clear to remove the chuck. The remaining screw will be far easier to remove once the chuck is off.

 

[BFBOB]

No such luck. I wonder if a solid carbide drill bit would drill it out, or just snap off too.
I suppose I could grind the old chuck off down to the taper. Might take a while ...

 

[Zeke]

Are you using any heat?

 

[BFBOB]

No- I thought of getting my 1A gas tip in there with an oxydizing flame and try to heat up the screw and broken off driver enough to draw the temper and then drill the head off. I'd hate to ruin the spindle, but as it sits it's unusable. First, I'll try going in with dental picks and the like first, see if I can persuade that driver fragment out.
Any guesses whether that screw is LH or RH? No fair flipping a coin!

 

[yaidunno]

The Jacobs site calls out LH threads for the retaining screw. Whats the part number of the chuck?

http://www.jacobschuck.com/drill-chuck-install.asp

 

[BFBOB]

It's a DC8K-33 Jacobs Taper 33 mount. The web pge you referenced only mentions screws on thread mount chucks. No mention of screw with taper - just like the effin' Rockwell manual.
I just did some spindle shopping, and all the new-part sources have that spindle listed obsolete, no replacement. I'll have to proceed very carefully from here. Thought I already was proceeding carefully.

 

[Provincial]

Some #33 Jacobs taper chucks have both the taper and a retaining nut. Does your chuck have a collar above the chuck body with a blind hole in it? Craftsman drill presses from the 70's had that system, and the end of the chuck key was turned down to fit the hole in the collar/nut to unscrew it. Unscrewing the nut forced the chuck off the spindle taper. You will have to get the screw out first.

You might have better luck removing the broken bit by freezing the area. It might shrink the small (low mass) bit more than the spindle assembly (much larger mass) and allow it to shake loose. There are some systems that accomplish this. Perhaps someone here knows about it.

 

[yaidunno]

Hum, that doesn't sound like much fun. There's a spindle listed for a Rockwell 15 on ebay. Not sure if its compatible with your machine though?

There isnt by chance a collar with a hole for a spanner between the chuck and the spindle?

Starting to sound like you might need to chuck it up in a lathe and get the screw head out of there.

 

[DavidB]

If you've never removed a chuck from a taper I'd suggest checking out this video starting at 3:30.

He shows the use of wedges, and what you can do if the wedges don't work. Tapers are pretty effective at holding things together. More so than you might think. If you don't have wedges, stop and buy some. They make the job easier.

Even with the screw broke off, the spindle is still good. I'd think, with the screw head broken off, that it should no longer be holding the chuck in place. You should be able to pop the chuck off with wedges and then take care of the screw. If it still won't budge, you can drill the screw out and then remove the chuck. The center screw is not required to hold the chuck on. I restored a Clausing that had a bad spindle. The spindle was expensive and I'd suggest doing everything possible to avoid having to find a replacement.

Also, a picture of the chuck from the side showing a little bit of the spindle would help us help you.

 

[A_Pmech]

Bob,

That would be the first taper mount chuck I've ever encountered with a screw in the bottom, but I can't deny what I see!

A carbide endmill will remove the broken tool and cut off the head of the screw, but it will be destroyed in the process.

Worst case, come out here and we'll turn that old chuck into chips on the Pacemaker.

 

[PugetDude]

Is there room to grind the head off the screw with an abrasive cone in a dremel or die grinder? (might have to make an extension to reach in there)
If you can get the screw head out of the way, you should be able to wedge the chuck off.
Good luck; post your results!

 

[BFBOB]

David B, the screw head is not broken off. would that it were! What's broken off is the Torx driver in the screw socket. But, there's hope. I got a dental pick in and it's wiggling a bit; I may be able to get it out and reattack with a new driver. Too bad I can't use my Snap-Ons. It's too deep in the chuck.
I've attached a couple more pictures. There's no hole in the chuck as one of you mentioned. The smaller threaded ring is pinned onto the spindle through the hole you can see. It is intended for mounting drill accessories after dismounting the chuck, which the manual assures me is easy to do. The larger threaded ring is the lower bearing retainer. Neither has anything to do with retaining the chuck. The accessory ring, though, would provide a surface for the wedges to work against.
I like the idea of drilling that screw out on the lathe. If I can get the Torx driver fragment out, I'll do just that. Cobalt bit? Allen screws can be tough.
Thanks, all

 

[thebeekeeper1]

I bent my spindle, but needed a new chuck also. I ended up taking it to a machine shop and the gentleman there fixed me right up--new chuck, straightened spindle, machine work, etc. for right at a hundred bucks. MUCH cheaper than the new spindle I couldn't find at any price.

 

[lilscorpion]

Pickle fork + whack. Leaves a little ****** on the chuck(that's the side to put the forks taper on) but you're pitching it anyway. That's how I do it and have done dozens. Once the chuck is off, deal with the broken screw or forget about it, it's not necessary.

 

[BFBOB]

Success...mostly.
I was unable to get the broken Torx bit out of the screw head. Grabbed a 1/4" masonry bit, put it on the SiC wheel and put a good edge on it. Then, to the lathe where I drilled out the screw very easily. Too easily in fact as I went too deep and drilled about 1/8" into the spindle.
I made a couple of the special wedges out of big washers and they popped the chuck off with little effort.
Now all I have to do is extract the rest of the screw. Maybe I'll get lucky and it'll be a LH, and self-extract as I drill it. It could happen.
Thanks to all - I floundered less with all the help!

 

[A_Pmech]

Good work Bob!

Being a Jacobs taper, it is self-holding. I wouldn't bother with the screw if it was my machine. Just seat the chuck with a few solid blows from a dead blow with the jaws wound up into the chuck body and it won't go anywhere.

 

[oldmachinenut]

This is what the original chuck would have looked like. The sleeve with the holes threads onto the large spindle threads. The sleeve when loosened removes the chuck from the taper.

Google Image Result for https://www.travers.com/media/catalog/product/6/3/63-002-068.jpg?optimize=medium&fit=bounds&height=450&width=450&canvas=450:450

 

[oldmachinenut]

A better view of the sleeve

 

[oldmachinenut]

Sorry, I just noticed this thread is 10 years old.
I did a Google search on using an old Chuck to hold small parts when grinding/wire brushing and this thread was in the results. I never looked at the date