Hello Friends, here you see my Weekend Project. I’ll automate all processes in XDisPlace. This means also to make a cheap ATC (Automatic Tool Changer). Video session about this topic next weekend. Hope you like it and i’m curios about your Comments 
I think the big question is, do you get enough torque from the spindle to really get the endmill tight enough in the collet?
@jlauer The answer is … maybe. It’s not enough to mill steel or aluminium, but for PCB milling is enough. I test this with my hands to loose the nut and it’s pretty strong. I use only the 1/4 current (~2A) to tighten this nut, to have some space to loosen the collet.
This is genius.
This is awesome. Can’t wait to see where it goes. Do they sell a pneumatic collet that you could command open and close?
@Frank_Graffagnino You know, my solutions most very simple. I use just the tourque from the spindle to tight the endmill for ~0.5 seconds. In the video you hear the “Klick”, in this moment spindle try to rotate with 2A for 0.5s.