Yes you're right. I missed that latest post 5mm tidbit, thought he only had the ability to take 1/8" shank tooling.
The arbors have a taper that mates to the spindle ID, the ones in the pic have a 5mm nose for mounting wheels with 5mm holes, really odd although the CBN wheel I got with it from NSK has the 5mm hole. The flanges I made adapt the 5mm nose to 1/4".
I didn't show the collet for 1/8" shaft mounted points but it mounts to the spindle with the same taper.
Off to the local hobby shop to p/u some bearings...