Is this Craftsman 12.5" DP Taper salvageable

[CH-Midget]

Howdy Folks... first time posting. I am mostly a lurker.

I am restoring a Craftsman Industrial DP (circa 1971), and the chuck fought me all the way but I eventually got it off and the 33 taper on the spindle looks like it spun sometime in its life. The chuck's taper looks OK so it must have been replaced. My question is what to do with the spindle. Is it salvageable?

total run out on the existing taper is hard to measure, but varies between .005 and .010 depending on where I measure it. The gouges contribute to the total runout.

Thanks again,

Mike

 

[crguy]

Howdy Folks... first time posting. I am mostly a lurker.

I am restoring a Craftsman Industrial DP (circa 1971), and the chuck fought me all the way but I eventually got it off and the 33 taper on the spindle looks like it spun sometime in its life. The chuck's taper looks OK so it must have been replaced. My question is what to do with the spindle. Is it salvageable?

total run out on the existing taper is hard to measure, but varies between .005 and .010 depending on where I measure it. The gouges contribute to the total runout.

Thanks again,

Mike

If you don't have the capability to recut the taper on that, I'd look for another spindle on Ebay.

 

[MShaw]

If you are resigned to replacing it anyway I would try this. Put it under power and use a mill file to dress out the roughness. Then mark two stripes with a grease pencil up the taper. Then rub the chuck on the taper and file the high bands where the pencil is rubbed off. Continue until you get near full contact. Then mount the chuck and check runout. If good, home free. If not, no worse off then you were.

 

[RoninB4]

-You can try the above suggestion by @MShaw but I wouldn't count on it working properly. The thing about tapers is that they work really well at locking together when they mate correctly. It only takes a very slight amount of difference (a few .001's) between the two surfaces (inner/outer) and they won't "lock" the way a taper should. It may even hold at the first contact ring but be free the rest of the length to wobble/release. The spindle may appear to hold the chuck until under power, it will then spit the chuck back off the taper. If there's a cutting tool in the chuck while under power you'll have whirling cutting edges you better not be near. Woodworking cutters would be the most dangerous. Straight downward pressure may keep the chuck in the spindle, although runout is likely, but any sideways pressure has a greater chance of releasing the chuck from the spindle. The surface finish of tapers also makes a big difference in the ability to "lock" the tapers together, tapers work much better with very smooth surfaces, that's why they're not cut on a lathe. Tapers like this are always ground for matching accuracy and for surface finish.

-Could this be properly repaired in a machine shop? Perhaps but it would take the right machines, a lot of trial/error, and I wouldn't offer a guarantee about it working as it should. There's a couple of methods for getting tapers to mate but they're not for the novice. Getting a new spindle (if available) would be less trouble IMO.

 

[CH-Midget]

Thanks Fellas.... much obliged. I found a NOS quill on eBay this morning and it is on the way. Y'all are great.
Mike

 

[Beerhippie]

I'm surprised that an "industrial" DP with J33 taper doesn't have the threaded collar for locking the chuck in place.

 

[CH-Midget]

I removed the collar as part of my dismantling. It is there… thanks. Mike

 

[RoninB4]

I'm surprised that an "industrial" DP with J33 taper doesn't have the threaded collar for locking the chuck in place.

-I'm not going to dispute what you've seen but most "industrial" grade drill presses I've seen/used didn't use a threaded collar. All of the shop DP's that I liked used just the spindle taper, they were often hollow with a spindle slot for a knock-out wedge. That allowed different sized adaptors for larger/smaller tang-end drills that were commonly used in lathes. The JT33 taper was most common in smaller DP's and perhaps I've not needed to mount a chuck to a DP with the JT33 taper.

-In reading;
Some of the Craftsman DP models were rebranded Walker-Turner models, which may help some seeking replacement parts or info.

-I usually caution against using any sideways pressure on a DP as there's a chance the chuck will come off the taper while rotating. I hadn't considered drum sanding. I have other machines for doing this but a lot of home shops don't and will have little other choice but to use the DP for this. Would still urge caution if you need to do this but using a DP for light milling is still not a good idea.

 

[Beerhippie]

-I'm not going to dispute what you've seen but most "industrial" grade drill presses I've seen/used didn't use a threaded collar. All of the shop DP's that I liked used just the spindle taper, they were often hollow with a spindle slot for a knock-out wedge. That allowed different sized adaptors for larger/smaller tang-end drills that were commonly used in lathes. The JT33 taper was most common in smaller DP's and perhaps I've not needed to mount a chuck to a DP with the JT33 taper.

-In reading;
Some of the Craftsman DP models were rebranded Walker-Turner models, which may help some seeking replacement parts or info.

-I usually caution against using any sideways pressure on a DP as there's a chance the chuck will come off the taper while rotating. I hadn't considered drum sanding. I have other machines for doing this but a lot of home shops don't and will have little other choice but to use the DP for this. Would still urge caution if you need to do this but using a DP for light milling is still not a good idea.

The use of a JT33 taper in something labeled "industrial" seems odd to me. I'd expect Morse taper for that.

The sideways pressure is what the collar is for--if you can find a chuck that uses it. I think this sort of usage is something you'd be more likely to encounter in a home shop than industry.

 

[RoninB4]

The use of a JT33 taper in something labeled "industrial" seems odd to me. I'd expect Morse taper for that.

-Usually is, not counting the B&S, Jarno, BT, CAT, and a few other orphan tapers.

I think this sort of usage is something you'd be more likely to encounter in a home shop than industry.

-Was trying to say that in a nice way in my previous reply, thank you for clarity.

 

[Cleave]

Sounds like you got yours a new spindle.
I recently got an old Jet 13-R benchtop DP for $50 knowing the "spindle was bent." Also needed a start capacitor, easy.
The taper - chuck interface was all trashed like yours but it didn't look bent. So I stuck that old spindle in my even older lathe between centers. I had an extra chuck laying around with a 5/8" straight bore so turned the business end down to a tight slip fit. Worked great with no discernable runout (I didn't measure it but it looks fine for all normal DP uses). Now its running a Procunier 2E tapping head for me plus other general duty (good to have a few DP's around to not have to change around jigs and setups).

 

[CH-Midget]

Thanks Cleave... interesting idea. Unfortunately I have space for only one DP, so it will need to do everything ;-)