Prusa MK3/S Full Bear LowRider Mod (+14mm/224mm Total Z Height)

thingiverse

Update 11/15/19: A minor collision point occurred in the updated Z-stepper mounts shared two days ago. I decided to start from scratch with the latest Bear V2.1 mounts, modifying them to suit the lowrider setup. The new parts feature all of the Bear V2.1 modifications, improved structural rigidity due to the reintroduction of angled support on both sides of the motor, and a reduced material reduction for the fan duct and pinda clearance cutouts. I've added LCD mounting brackets that lower the LCD 9.5mm for clearance of the bed frame. These are installed and work as expected on my printer. Also, I have reduced the OAH after modification to allow for successful XYZ calibration. The newest firmware, based on 3.8.1 and including linear advance 1.5, is available here: https://drive.google.com/open?id=19GoFA7jdlqcUfbDV070-wNWXEH3udTQm Update 11/13/19: I've revised the Z-stepper mounts to include all four mounting holes for the stepper motor, as well as most of the Bear V2.1 updates featuring a tighter fitment around the stepper's sides and a recess for perfect alignment between the mount and the motor's upper bezel. Making clearance for the pinda and fan shroud required integral supports on the right mount. I'm running the BNBSX Short Ears extruder, and everything has plenty of clearance, but YMMV with other extruder designs. Update 8/26/19: I've been running the updated firmware with 229mm maximum Z height and LA1.5 on my Mk3S full bear since 8/19. The printer is able to print normally at the new maximum Z. So far, there does not appear to be any unexpected issues created by the lowrider mod. With the recent announcement of the revised bear frame allowing all Mk2/2.5/S machines to utilize the same frame as the Mk3/S, I hope to soon update this mod (as necessary) to work with the Mk2/2.5/S. I anticipate a maximum build volume of 221mm for the Mk2/2.5/S with the lowrider mod. ALSO, now that I've had a chance to test the mod, I'm planning to modify the z-motors mounting brackets to address the collisions reported by users. Until said solution is available, I do not recommend installing this mod. Update 7/31/19: I'm printing a benchmark at maximum Z height right now. As soon as it's done, I will install the lowrider mod on my mk3s and load up the custom firmware I just finished (https://drive.google.com/open?id=1CvUE573YDk-4MFuyfOQODluytIZ_yKcc). Update 7/30/19: NOTICE: It has been reported that using this mod will result in multiple collisions, including a collision at the far left (home) position of the x-axis and another at the far right position of the x-axis. These collisions involve the fan duct (on the left) and the pinda (on the right). I am looking into a solution that will include modification of the z-motors mounting brackets. This mod is untested, so try at your own risk. All y-rod, motor, and pulley mounts have been moved down by 14mm and modified to plane from the bottom of the front/rear extrusions rather than the top. Custom firmware will be available in the future. This design will be modified (if necessary) for the mk2.5s full bear in the near future. Note I've included an adjustable y-idler pulley with a 3D printed 20T pulley that utilizes two MR63ZZ L-630 bearings, as well as an m3x12 button-head screw. The standard pulley carriage from the original design (see remixes) should work for users who don't want to build the plastic 20T pulley and use the m3 screw.