Hi guys. Today i'd like to present to you my latest upgrade to my old ROBO R1. Few years i had my own direct drive design posted here https://www.thingiverse.com/thing:550788 It worked nearly flawless for several years and i had absolutely no reason to change it. Original ROBO3D gantry is setup in such a way where belt sits behind the carriage. This presents a big problem with whiplash effect that contributes to bearing wear and rattling noise. I just finished testing and finally posted my latest design here https://www.thingiverse.com/thing:3604234 This design has custom made gantry which allowed me to place belt in the dead center of the carriage. No more whiplash Since there are couple of geared extruders on the market today (BONDTECH and TITAN) i decided to buy both and see how they operate. I designed 2 carriages, one for each type of extruder. Those extruders are 1:3 gear ratio (i think) and they allow for smaller motors to be used. How ever, i think extruder its self+smaller motor=1 larger motor anyway so....... Anyway i kinda measured steps for this ratio and 828 seems to work. Also i had to reverse direction for E0 in firmware since these extruders kinda flip things around. My final conclusion on two extruders i used is simple: Keep in mind, i did not use original bondtech, i used cheap chinese replica called DOTBIT dual drive what ever. $20 So DOTBIT is very well built and matches the total width of the motor. 1 thing i dont like about it is that it does not allow filament pass through by hand easily. Pulling the lever releases the tension but the gear is still in the way. So its hard to pull filament out or push it in without turning the gear by hand. TITAN is wider then the motor but it allows to move filament in and out freely. TITAN is somewhat complicated. Too many things can go wrong with it and the worst part about it is that the lever pivots on the motor shaft its self. When that happens, it applies tension to the motor shaft, slowing motor down. Motor has to work harder and gets hotter as result. In short, i dont like either one of them but they do perform well and its just something you have to live with if you end up using it. Perhaps i can make another carriage that uses typical direct drive extruders that have no gear reduction mechanism such as in the picture below. These are cheap and good too. Just be sure to get desired orientation. They already have hole for m4 screw to mount it to the carriage from the bottom. Ill start working on that and post it on my thingyverse as well.