Drill chuck

[nightowl]

I have just purchased a drill chuck for my Jet Mini. It works great but when I am makin bottle stoppers and have to move the tail stock in order to round the end or otherwise shape it the shaft of the drill chuck works loose. I have put some masking tape around the shaft and that seems to help, but do they make anything else to keep this from happening? I am not sure if the adhesive from the masking tape will cause problems down the road? Any thoughts would be appreciated. Thanks.

 

[Aderhammer]

Turn down the speed, light cuts, sharp tools! I do not have any problems, only other option is to use a draw bar

 

[pipeyeti]

Safest to use a drawbar.

 

[Aderhammer]

It can be done safely with practice. A drill press doesn't need a draw bar to work.

 

[maxwell_smart007]

Depends if your floor is level...my lathe kept working the drill chuck (not drill press, Andrew) out of the headstock until I shimmed the legs...

But now I also use a drawbar!

Andrew

 

[Randy_]

Originally posted by Aderhammer

Turn down the speed, light cuts, sharp tools! I do not have any problems, only other option is to use a draw bar.

Only problem with that suggestion is that most MT arbors for Jacobs chucks are not drilled for drawbars.

 

[Randy_]

Most of the time, the fit of the arbor and the spindle will be close enough that there won't be a problem.

First thing to do is carefully clean out the spindle taper with a paper towel and a little solvent of some sort. Any sort of dust or residue will interfere with the fit of the chuck arbor. You might even want to go so far as to wrap some fine steel wool around a 1/4" dowel and lightly scrub out the spindle taper. Use the same paper towel and solvent to remove any grease or oil from the arbor. If you have some 600 grit or finer sandpaper, you could give the arbor a light polish to remove any surface irregularities.

Now open the chuck so the jaws are fully retracted and insert the chuck in the spindle. The jaws should be below the face of the body of the chuck. Now gently seat the chuck in the spindle with a light tap from a piece of scrap 2x4. Do not be heavy handed here or you could damage the lathe bearings.....just a light tap is more than sufficient. If you want to carry things one step further, put the chuck in the freezer for an hour or so before before seating in the spindle.

If none of the above works, you can purchase an arbor that is drilled to accept a drawbar. You will need to match both the MT of your lathe and the JT of your chuck. These arbors can be had for less than $10 from: http://www.littlemachineshop.com/products/product_search.php?critFast=arbor

 

[nightowl]

Thanks guys for the advice. I will try your suggestions.

 

[stevers]

Had it happen, slowed down a little and took smaller cut to reduce vibrations.

 

[Rifleman1776]

Randy covered it. All that doesn't work, only answer is a drawbar. It is something we all face.

 

[randyrls]

Originally posted by Randy_

[teal]Most of the time, the fit of the arbor and the spindle will be close enough that there won't be a problem.

If you want to carry things one step further, put the chuck in the freezer for an hour or so before before seating in the spindle.

David; All your ideas are good ones. Cleaning and degreasing should solve the problem. Lathes tend to accumulate a fine wood powder inside the spindle. I have never had to make any drawbar tighter than finger tight.

Use caution if trying the freezer trick. Don't do this unless your lathe has a thru hole. You could seat that drill chuck in the lathe head permanently! I put a pulley in the oven to heat and expand it so it would fit on a shaft. Later I had to use a gear puller and lots of muscle to remove the pulley!

 

[Randy_]

Originally posted by randyrls

.....Use caution if trying the freezer trick. Don't do this unless your lathe has a thru hole. You could seat that drill chuck in the lathe head permanently! I put a pulley in the oven to heat and expand it so it would fit on a shaft. Later I had to use a gear puller and lots of muscle to remove the pulley!

In theory, Randy is correct; but I'm not sure it is really something to worry about in actual practice. If you look at the formula for the thermal coefficient of steel, it is approximately 6.5 times 10 to the -6 divided by the temperature change in °F. For a #2 Morse taper, that works out to about 0.00026"....2.6 ten thousandths of an inch. Not a terribly large amount! It might be enough to snug up the fit on a MT that is already close to: but not quite, a perfect fit in the socket. I doubt it would seize up an MT so tight that it could not be removed fairly easily.

The other point is that in Randy's example, he heated his pulley in the oven so it is reasonable to assume the temperature change factor was 4 to 5 times larger than what is used when a MT goes from room temp to freezing.

If one of our resident machinists or mechanical engineers wants to contradict my thinking, I'm all ears!!

 

[pipeyeti]

Originally posted by Randy_

Originally posted by randyrls

.....Use caution if trying the freezer trick. Don't do this unless your lathe has a thru hole. You could seat that drill chuck in the lathe head permanently! I put a pulley in the oven to heat and expand it so it would fit on a shaft. Later I had to use a gear puller and lots of muscle to remove the pulley!

In theory, Randy is correct; but I'm not sure it is really something to worry about in actual practice. If you look at the formula for the thermal coefficient of steel, it is approximately 6.5 times 10 to the -6 divided by the temperature change in °F. For a #2 Morse taper, that works out to about 0.00026"....2.6 ten thousandths of an inch. Not a terribly large amount! It might be enough to snug up the fit on a MT that is already close to: but not quite, a perfect fit in the socket. I doubt it would seize up an MT so tight that it could not be removed fairly easily.

The other point is that in Randy's example, he heated his pulley in the oven so it is reasonable to assume the temperature change factor was 4 to 5 times larger than what is used when a MT goes from room temp to freezing.

If one of our resident machinists or mechanical engineers wants to contradict my thinking, I'm all ears!!

I'll use my $1.99 bolt from pops hardware as a drawbar. No math required with that[]That stuffs confusin' man

 

[Randy_]

Originally posted by pipeyeti

I'll use my $1.99 bolt from pops hardware as a drawbar. No math required with that[]That stuffs confusin' man

No doubt that a drawbar is the best way to go; but as was pointed out earlier, many drill chucks are "NOT" threaded for a draw bar so alternatives do need to be discussed.

 

[great12b4ever]

Randy, If you heated the pulley in the oven, you probably reached a temperature of 250-300 degrees. This would give you a Thermal co-efficient of approx 3.9882, based on an external temp of 70 degrees. This, as Randy said, would be more than enough to create the seizing problem, ergo the need for the gear puller and the brute strength. Based on freezing at around 20 degrees and the 70 degree ambient temperature, the other Randy nailed it almost on the head for the small amount of change. This should not allow a total seizing like the heating does, and a simple knock out bar using hand pressure should be sufficient to dislodge the chuck from the Morse Taper in the head stock. One word of advice. If you do the freezing, be sure to put the chuck in a good double zip-lock back to minimize the moisture from the freezer getting into the workings of the chuck and creating rust. Another word of advice would be to spray/coat the chuck with a good 3 in 1 oil before putting into the zip lock bags. I would not use W.D. 40 as that product tends to attract all sorts of air borne particles.

 

[byounghusband]

I had the SAME problem.... So this is what was suggested to me:
Try checking out LMC and purchasing the MT2 Collet set. They have a range of sizes 1/8" through 1/2" in 1/16" increments and they are all 3/8"-16 threaded for your draw bar. I bought this kit and use it for my stopper mandrels. You could also buy the specific collet for your mandrel as well....

http://www.littlemachineshop.com/products/product_view.php?ProductID=1752&category=

 

[jcollazo]

I have the 1/4" and 5/16" MT2 collets on my website for $7.50. Drawbars are $2.00.

 

[randyrls]

Originally posted by great12b4ever

Randy, If you heated the pulley in the oven, you probably reached a temperature of 250-300 degrees.

Yes; you are probably correct, but I have done dumb things with the best of intentions. The drawbar is always the best solution.

 

[loglugger]

Drill and tap the MT on the drill chuck and use a drawbar
just not to tight.
Bob

 

[Randy_]

That is certainly an alternative; but that would require some mechanical skill and special tools that most folks here probably don't possess. It would be a lot easier and more economical for most folks to just buy a replacement chuck arbor that is already drilled and threaded.