MakerBot Print is our newest print-prepration software, which supports native CAD files and STL assemblies,
allows you to interact with all your printers via the Cloud, and many other exciting new features.
I must admit the bearings have caught me out a bit as in the UK it was really straight forward to get hold of the flanged bearings. I choose the flange bearings so I can print without support (design without overhangs) and flange bearings make this really easy. You could use skateboard bearings for the pitch bearings although they are a lot thicker and that might cause some issues but without measuring some I couldn't be sure. If you want a cheap solution how about design a plain bearing (no balls just sliding surfaces) and grease them. I could knock up a model if you want to print and test them?
I used an RPi to measure the RPM, and also have a current measuring device attached which is pretty cool on a Pi Zero Wifi with a tiny battery and charger. My codings pretty rough and ready though so its not very pretty :)