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!!