I posted the latest drawing of the XY assembly on the
drawings page. I tweaked the idler pulley assemblies a little. I was using two brackets per pulley, but that turned out not to be required. I decided it would be better to have another Misumi bracket on the other side to more add side to side stiffness. If you fab'ed some parts already. They will work. You will just have two extra pulley plates.
I also got rid of the o'ring concept I was playing with to hold the bearings in place. My material came in so thin that it did not fit right and the regular hardware was holding it fine. If you have thicker material and are having trouble, let me know. I have a small amount of thicker material I can try out. I can also cut a few out of the thinner material for you. My router can be dialed in so that it is a nice tight, almost press fit.
My pulleys arrived today so I might be able to get them installed and start re-aiming the mirrors.
I also have a long term goal of simplifying the enclosure skins. I want some way to fab them without the large router that I use. If anyone has any ideas or some alternate materials, I would love to hear about it.