I have a small milling type spindle to make, for a specialty purpose. It will be taking end mills (in holders, most likely), and stub arbors to take saws and cutters of various types.
The open item at present is the spindle taper. There are a number of possible choices, each with positives and negatives. It is a definite advantage if the taper is self-releasing, like the NMTB tapers.
Due to space restrictions, it probably does not have room for anything as large as an MT3, or NMTB30 taper in the spindle end. I'd like to keep the spindle not much over 1" diameter, and it can't be very much more than 5" long. The MT3 is longer than desired, isn't self-releasing, and is too large in diameter, while the NMTB30 is already too large in diameter. R-8 is out as it is even bigger.
Digging in the Machinery's Handbook, I found NMTB10 and NMTB20 tapers. Of course, they are nearly perfect. Trouble is, nobody seems to ever have used them, and no holder or tooling of any sort is available in those sizes. Smallest is NMTB30, and even that size is limited in available tooling. No help there.
I could potentially use a 3C collet. But they aren't as stable as an end mill holder, and are no help on arbors at all.
Rolling my own seems to be the worst idea, followed closely by using a "standard" for which I would have to make all tooling, such as the NMTB10 or 20.
I keep coming back to the MT2 as the best of a bad lot. End mill holders, collets, and even arbors are available. But that taper is self-locking, and requires beating to get it out of the spindle. Not good, or at least not desirable.
Have I missed any viable standard tapers that might fit the bill?
The open item at present is the spindle taper. There are a number of possible choices, each with positives and negatives. It is a definite advantage if the taper is self-releasing, like the NMTB tapers.
Due to space restrictions, it probably does not have room for anything as large as an MT3, or NMTB30 taper in the spindle end. I'd like to keep the spindle not much over 1" diameter, and it can't be very much more than 5" long. The MT3 is longer than desired, isn't self-releasing, and is too large in diameter, while the NMTB30 is already too large in diameter. R-8 is out as it is even bigger.
Digging in the Machinery's Handbook, I found NMTB10 and NMTB20 tapers. Of course, they are nearly perfect. Trouble is, nobody seems to ever have used them, and no holder or tooling of any sort is available in those sizes. Smallest is NMTB30, and even that size is limited in available tooling. No help there.
I could potentially use a 3C collet. But they aren't as stable as an end mill holder, and are no help on arbors at all.
Rolling my own seems to be the worst idea, followed closely by using a "standard" for which I would have to make all tooling, such as the NMTB10 or 20.
I keep coming back to the MT2 as the best of a bad lot. End mill holders, collets, and even arbors are available. But that taper is self-locking, and requires beating to get it out of the spindle. Not good, or at least not desirable.
Have I missed any viable standard tapers that might fit the bill?