Robo3D Direct Drive Extruder MOD

thingiverse

I've used this for years and it's worked very well with absolutely no issues. Most parts are reused. I highly recommend using REVERSED design so that the filament puller faces you instead of the back of the printer. Lower center of gravity will give you room to increase speed without sacrificing quality, while less weight will minimize whiplash effect responsible for creating bulging corners. Less distance for the filament to reach the nozzle will help with flexible filaments. I've included three carriages now. If you don't want to modify the stock carriage, print one instead - just print it in the orientation provided. Bearing hole size is standard (15mm), but not every printer can print the exact size, so I've included #3 sizes of the carriage with a 0.2mm increment in diameter. The carriage has two loops for easy belt attachment; no zip ties are needed. If you print a 15.2mm carriage and it's too tight, print a 15.4mm one. Using a round file can help the bearing to go inside easier without having to reprint. The 15mm carriage is the original (almost guaranteed to be too tight), the 15.2mm (in my case, it worked), and the 15.4mm (for those who still end up with a too-tight result). List of things you reuse and need to get: 2 wood screws (find them in the garage for free); cut them to 15mm entire length to attach belt clamp. $9.00 MK8 Drive Gear Filament Pulley $5.00 5x10x4mm Ball Bearing - MR105 2TS PTFE tube (need about 10mm piece; you may have it laying around) All screws and springs are used from old extruder. Two springs combine into one, making a strong spring, so no need to buy any unless you need more tension. One long screw and a nut (that gets jammed into Base Clamp) to attach the hotend to the base. Find a screw no more than 20mm long that would fit through the bearing (tight but allowing it to spin; up to 5mm across). PRINTING: I highly recommend using CURA for printing. Do not print 100% solid; it will cause parts to shrink and not work properly. 20% infill is good, with two lines of perimeter. FIRMWARE: Need to reflash ROBO's firmware (Search robo3d forum how to flash). Look into file "Configuration.h" and find the line below: #define DEFAULT_AXIS_STEPS_PER_UNIT {80,80,2267.72,723.38} Change 723.38 to 145.51. Save and Upload to the printer. Modification required: The carriage would need to be shaved off to allow the hotend to go through (UNLESS you downloaded already redesigned carriage). Print the provided template model that would give you a pretty good guide as to where to cut. If the motor bumps into the belt, move the pulley that's on the X motor back as far as it can go.