This is the design I intend to make for all my new arbors.The locking collar slips through the cutter and into the arbor. It is self-centering and self tightens as you use it. You only need to lightly lock the screw. This one was meant to be inserted into a 3/8" end mill arbor.
The next units are Taig's design. I have made a few of these. In this case the arbor body itself holds the cutter as you can see in the picture below on the right. The collar holds the cutter down but does not act as a centering collar.
Below is the blade holding unit dissassambled -- you can see how the cutter would be held!
These are two end mill holders made from Taig arbors. The left one holds rare 1/4" shank end mills. The right arbor holds 3/8" shank tooling
Below is the miniature micrometer boing head I built and shot a video about its construction. It is built around a blank arbor and I built it with my shop made mill.
Here are some more accessories I've made as well as some slitting blades I've picked up at various shows and used tool sales. Top left is a Taig Grinding arbor and one of the wheels it comes with. To the right is a double cutter flycutter mounted to and arbor and to the far right is a larger grinding wheel that I use with a special fixture to sharpen the ends of end mills using the mill and the 60:1 geared dividing head.