http://www.precisebits.com/products/equ ... PG!!!#Tabs
It lets me use the 1/8 in (and some dremel) endmills I already have in the DW611 spindle and has no appreciable runout.
I tried a cheap collet insert adapter first and I think the runout caused an endmill to break once it was under a load cutting MDF, that same bit and load worked fine before with a dremel.

Those hardened endmills really hate to be flexed at high speed.