Another Printrbot Simple Smooth/Threaded Rod Stabilizer
I liked evannguyen's idea for a Printrbot Simple bracket to keep the tops of the rods together, but I had trouble printing it since the wall thickness was too small on the threaded rod. I made my own version using the Simple design files for dimensions and I'm pretty happy with the result.
I printed this at 0.3mm and 15% infill. It fits securely but isn't hard to place.