I see from the Machinerey's Handbook, that the actual, given, tolerance on an MT is 0.002 per foot on the rate of taper.
For a shank, it must increase taper rate, (making large end bigger) and for sockets the opposite, making large end smaller. In that way the small end will always be the loose point.
That seems like a lot..... it suggests that for a 3" long taper, about an MT3, there might be a half-thou looseness.
I have some MT2 blank arbors that I obtained for making T/S tooling. They are some unknown amount small at the small end, but are small enough there that they won't rub off a stripe of marker ink all around.
My suspicion is that that is probably at least an error of the max amount, since for an MT2 that would be only about 0.4 thou of error. Maybe a little more, since there is no rub-off at the end, but I don't have a way of measuring it aside from a complex setup of gage blocks and sine plate, which I would rather not do. Besides, teh exact error isn't really the issue.
I cannot FEEL any looseness, but obviously it is there.
In practical terms, what is the effect of a maximum (0.002 per foot) error in taper rate?
For a shank, it must increase taper rate, (making large end bigger) and for sockets the opposite, making large end smaller. In that way the small end will always be the loose point.
That seems like a lot..... it suggests that for a 3" long taper, about an MT3, there might be a half-thou looseness.
I have some MT2 blank arbors that I obtained for making T/S tooling. They are some unknown amount small at the small end, but are small enough there that they won't rub off a stripe of marker ink all around.
My suspicion is that that is probably at least an error of the max amount, since for an MT2 that would be only about 0.4 thou of error. Maybe a little more, since there is no rub-off at the end, but I don't have a way of measuring it aside from a complex setup of gage blocks and sine plate, which I would rather not do. Besides, teh exact error isn't really the issue.
I cannot FEEL any looseness, but obviously it is there.
In practical terms, what is the effect of a maximum (0.002 per foot) error in taper rate?