Ok, so for the past couple years my Robo3D R1+ has been spitting out phenomenal prints comparable to my Original Prusa MK2S and MK3, and now all of a sudden I'm getting prints that look like they're out of a 70's horror movie (they used to make them real scary back then). It would appear to be printing fine for a while, then all of a sudden... Well, a picture is worth a thousand words, so here's 5... I have my e-steps calibrated pretty well. I've tried using several types of filament. I've tried the same filament on my Prusa MK3 and the Benchy comes out perfect. My belts are adjusted well, I've tightened every nut/bolt/screw on the machine. I'm using an original E3D v6 with 0.4mm nozzle I have a strong suspicion that it has something to do with the extruder itself. Not sure if it's the nozzle, throat, or what, but the reason is as follows: I did a little test on the Robo and performed the exact same test on the MK3: On the Robo, I extruded 100mm of filament at 130mm/min, and the result is exactly what you see in the picture with the green filament. Performing the same test on the MK3 produced the results you see in the picture with the orange filament. Clearly the green filament on the Robo is coming out much thicker than on the other MK3 (Robo: 0.68mm thick, MK3 = 1.10mm thick). I measured how much filament was actually being extruded on each printer (by using the known method of calculating e-steps, and it was 100mm, just like I specified. Furthermore there appears to be a problem with the pressure. When I extrude a couple mm on the Robo, as soon as it stops, it sucks in quite a bit of filament back into the nozzle. What would cause this? It's not normal, and it never used to do that. I'm using PLA at 195c nozzle, 60c bed. Thanks in advance!