Modifications and add-ons for PrintrBot Simple V2. All items designed at 3dtin.com and I couldn't figure out what the heck their units were doing, so everything needs to be printed at 0.7 scale - sorry!
Edit: Added a second revision of the flanged cap. Depending on your reel, this one might fit better (slightly longer).
Edit: See new spool support parts at http://www.thingiverse.com/thing:149928
PLA Feed Tube: I've been having a big problem with the V2 direct drive extruder. I traced it to the filament walking off the bearing to one side or the other, depending on the angle it was coming in at. The stock guide didn't provide sufficient guidance to the filament, so I designed this insert. Had zero problems since installation. I installed the tube in the stock guide, then reamed the hole with to 3/32" (for 1.75mm PLA). You might want to grip the insert with pliers as you ream, to stop it from spinning in the stock guide.
Fan bracket: Simple right angle brackets to install an 80mm fan on the print bed. You've got at least one old tower PC kicking around you can scavenge the fan from, right?
30.5 mm flanged cap: Fits nicely in a standard spool of PLA. Lightly reaming the centre hole allows it to turn freely on an 8mm smooth rod with no bearings required. Edit: Added a second revision. Depending on your reel, this one might fit better (slightly longer).
8mm foot/elbow: As printed, the holes will accept the old threaded rod from the V1. (I use that rod as one of my verticals.) With a little reaming, it will accept the 8mm smooth rods. Depending on the orientation you print these at, you might want to be very careful reaming, and not force the rod in, or you might split apart your layers.
For general interest: I used a piece of 4"x6" glass from a cheap picture frame, held on with small binder clips. (The arms can be removed after installing the clips.) I use no-name green painter's tape and don't generally have a problem with adherence, now that I've got my Z home dialled in. This glass will need to be replaced, as it's slightly too small now with the changeover to the V2.