Drill Chuck - Seating on Spindle?

If it's a decent fit then shrinking it in place may well make it permanent -- you don't want that.

I've always assembled these with an exceedingly light coating of very light oil -- basically I clean the parts off with oil on a rag, wipe them off firmly, and assemble. The oil limits corrosion, but is in such a thin film that the surface strength is exceeded when you bear down on the drill and that makes enough friction so that everything works.

The only time I've had trouble is when I've been abusing the joint, by putting side loads on it, or making it vibrate under light down-force, or other such foolery. Even there it doesn't slip so much as the morse adapter falls out of the spindle.

You've probably got a fit problem. I know this is inconceivable with newly purchased budget Chinese equipment, but none the less yours may be the rare case where the insanely quality-conscious Chinese labor force has slipped up -- perhaps they were buying parts from Germany, or something.

Do a fit check, per RoyJ.

I spilled my coffee through my nose... :)

T.Alan

I wondered who bought up all the good Jacobs and Bosch chucks!

LOL Rob

Thanks for the replies. The problem seems to have vanished ... for now. We'll see. I appreciate the suggestions.

Jones.

After verifying the fit, and making sure everything is clean, I was always taught to apply some white chalk to the male taper...

Burns doesnt it...Dew through mine.....

"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.

Think of it as having your older brother knock the s*it out of you for torturing the cat." Gunner

Jon wrote: (top posting fixed)

-- snip --

That's interesting. Does anyone here know what that does, and how good an idea it is?

Chalk -

Softer than either steel. powders finely and fills voids, making contact all around.

Mart> J> (top posting fixed)

Watch the taper specs- You may have a JT 33 chuck and a B-16 arbor or vise-versa- they are very similar, but will not seat together properly.

It's in old(1890s) machinist's manuals, three stripes of blackboard chalk on the surface of a taper shank WILL make it stay put. That's assuming no pimples, rings or gouges on the mating surfaces. Been doing it as long as I've been messing with old machinery.

As to why, the old books never addressed that, but one old formulary used rosin as a binder for blackboard chalk.

Stan