Originally Posted by
bergerud
It sounds like you like 1/2" shanks. In that case, you should keep the CT and use an ER11 adapter for the small bits. I do not like the straight ER11 spindle. It is too hard to change bits on the machine with the small collets and small nut. My favorite is the ER16M. I think the ER20 is too big. As for inertia, I have wondered myself. It seems to me that the extra rotational inertia of a big chuck does more harm than good. It is hard on the flex to always spin it up. The argument that inertia helps in the heavy cutting makes sense when the heavy cutting comes in short pulses. That was another reason I went with the ER16.
Another problem with the straight ER spindle is that of changing bits in a multi-bit project. If you do not have a lock button, the two wrench method gets a bit tedious. If the shank sizes of the bits are different, you have to also change the collet and nut. When you take all of this into account, the ER11 adapter starts to look good. Having a set of them going in and out of a CT would be a sweet setup.
(Remember to email Jeff if you are interested in an ER11 adapter. Lets not let this important message get buried in the thread.)