I love Brooke Drum's awesome 3D printer (was on Kickstarter - now at printrbot.com). I wish I had more time each week to work on assembling it, but I do keep hitting little speed bumps along the way.
Here's all the stupid things I'm doing wrong following the printrbot videos and also the occasional changes to the bill of materials and instructions that are tripping me up. Maybe this will be useful to someone else who is assembling an original printrbot (not the PLUS or the LC/lasercut version)
1. Don't get those rods perfectly parallel before you work out (using the base plate) just how far apart they need to be. You'll have about 1 1/2" of threaded rods sticking out of one side.
2. Don't screw your motors in before you flat them. Flatting involves taping off the motor, carefully putting it in a vice and filing one side of the shaft flat. Brooke explains it in one of the later videos.
3. Don't freak out when it calls for three 16mm black screws in this step and you only have one left because you used two on the bearing guide. He's changed them to 8mm in the video.
4. I'm really not sure what to do about these yet. The video shows a different construction.
Open question: What to do with the new style 5mm to 8mm flexible shaft coupling? And whether or not you need to flat these motors?