I intend to cut waxes for investment to make miniature castings. The current project is a 1/3 scale Harley Davidson "F" head. Most tools would be .125", but some detail could require smaller. The Series I has 30 NMTB and the usual suppliers only show that holder for DA collets. If I go with a stubby I can use either ER 11 or 16 collets. Is there a preference for either of these collets?

You should be able to get pretty much any collet you desire. DA, ER series, etc. I think you need to explore other suppliers if your current ones don't offer the selection. I have some NMTB 30 that are ER32, and have seen them pretty much in any combination you could dream up.

Thanks Sam