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View Full Version : proper way to set stub-arbor in drill chuck



wingnutt
11-09-2007, 08:33 AM
whats the proper way to seat a stub arbor into a drill chuck?

thanks,

i just got my new mill-toys in from CDCO
no im not related, or even have any investments, ,,,,,,,anywhere for that mater,,,,
EI

SGW
11-09-2007, 08:47 AM
You mean mount a drill chuck on a taper shank? That's been discussed in the past, so an archive search should turn up some opinions.

I think the recommended way is to clean both surfaces, then press the taper into the drill chuck with a hydraulic press. Lacking a hydraulic press, I'd probably set the taper in the chuck, set the chuck on a solid surface, and give the top of the shank a clout with a non-marring hammer. (Open the chuck jaws all the way first, so the chuck is sitting on the chuck body.)

Other thoughts include warming the chuck, cooling the shank, then pressing them together.

Some suggest Loctite, but IMO it won't help; if the two parts are together as tight as they ought to be, it will squeeze out all the Loctite.

DR
11-09-2007, 08:55 AM
message deleted

Peter N
11-09-2007, 09:26 AM
If it is a drill chuck, then jacobs recommend just tapping it into place using a block of wood.
On tapered shank arbors they specifically advise against using an abror press.

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


Peter

SGW
11-09-2007, 09:42 AM
Good link, Peter!

Peter N
11-09-2007, 09:53 AM
I found it when I was checking methods for chuck dis-assembly, and I don't know if you spotted it, but the info under "Chuck Repair" certainly saved mine from the grief it was due to get from a hammer and drift!

Peter

wingnutt
11-09-2007, 10:33 AM
THANKS guys,
i wanted to do it right the first time,
goterdone now,,:D

EI

Forrest Addy
11-09-2007, 11:29 AM
Before the lawyers got into it, Jacobs use to reccommend a "shrink" installation. The chuck and taper is cleaned to dry metal, the chuck is heated to 350 degrees F, then the room temp stub taper is quickly inserted, and the assembly allowed to cool to room temp. The resulting connection is equivalent to a 2 ton press assembly and far safer than smacking things with a hammer.

Do not use locktire or other adhesive. It's weaker in shear per unit area than a solidly seated, self holding metal to metal taper.

Swarf&Sparks
11-09-2007, 01:40 PM
Dunno bout dem lawyers, but if we're talking JT, usta just clean em and clout em, give a preparatory twist, then a medium-heavy slap (with a mallet, or lump of hardwood).

Never had one drop off yet (had a few drop out of the MT quill, but never the JT)

rkepler
11-09-2007, 07:02 PM
Before the lawyers got into it, Jacobs use to reccommend a "shrink" installation. The chuck and taper is cleaned to dry metal, the chuck is heated to 350 degrees F, then the room temp stub taper is quickly inserted, and the assembly allowed to cool to room temp. The resulting connection is equivalent to a 2 ton press assembly and far safer than smacking things with a hammer.

I once got a nice Jacobs BB chuck on a crappy shank, and went about removing the shank. Tried the standard wedges, no go. After hammering the wedges off I tried threading the crappy shank and using a nut to wedge the chuck off the taper, nope. Drilled through inside the chuck and tried pressing off the taper. Nope. Heat and cold did nothing. Determined to remove the shank I tried combinations of methods - tapped the hole through and ran a bolt through the hole and did the wedge thing in the back, nope. Finally drilled the reamed the hole, packed the cavity with grease, put a dowel pin in the hole and set the whole mess on a press - it finally came out at something like 8 tons.

The chuck was marked with markings from Los Alamos National Labs and one day I ran into someone from the shops there and mentioned the difficulty. He was surprised that I'd been able to get it off at all - seems they'd heat the chuck to about 300 degF and dip the shank in liquid nitrogen before putting them together. If something happened to the shank or body they'd toss them before trying anything to separate them.