Robo R2 Print Head Plastics

The purpose of these plastics is to improve the print output. To reduce ghosting the top plastic is beefed up to reduce flexing during extrusion starts/stops and changes in direction. The arm has a large plastic bearing which allows the stepper to be secured in the upper right, making the mounting stiffer. The arm has variable spring pressure, I found that soft PLA wants less pressure to prevent heat creep and improve finish. The bushings on either side of the bottom plastic provide a very l