Modified Wilson II Printer

thingiverse

Human: NOTE: Please see important update 3/27/2020 Originally, I became interested in converting my Flashforge Creator Pro to use a Diamond hotend. After much work toward this end, I decided that it would be more practical to build a completely new printer. So, as a starting point, I chose to use the Wilson II/Prusa design as published by Marty Rice www.thingiverse.com/thing:1086101 . I named my printer WWIII (Weber-Wilson III). My printer is basically the same as the original, but with a 300mm x 300mm bed and many changes or modifications to most of the parts. There are two power supplies, a 24V supply for the heated bed, and a 12V supply for everything else. In order to isolate the two supplies and take the high current bed load off the mainboard, a solid-state relay is utilized. The two supplies fit nicely between the Y-axis rails along with the relay. I modified the original bed mount using bearing holders that eliminate the original wire-tie mounts. All parts were printed in ABS. The mainboard is a Rumba with six TMC 2208 stepper drivers. Firmware is Marlin 2.0. The three extruder steppers are 1.8° 17HS8401 /48mm long. All other steppers are 0.9° 17HM19-2004S 48mm long. One of the major challenges of this design was the wire management. A couple different types of flexible wire chain was used for this purpose. (JD Miles: www.thingiverse.com/thing:1760952) I also used the RepRap Full Graphic Smart Controller and modified it so the encoder has a thumbwheel and separate push button for control. I changed the AC power input module to use a panel mount power socket with fused switch which uses a standard removable power cord. A Y-axis brace (threaded rod) was added to the Y-axis due to the flex of the longer end pieces. A touch probe was installed on the carriage for precise bed leveling. Since I often print with only one filament at a time, I found that the idle filaments get "cooked up" in the nozzle and cause a clogged nozzle. To prevent this from occurring, I run an extra 50mm of filament from each of the three filaments at the conclusion of every print. I used scripting in the slicer program to do this. I have uploaded my current Marlin 2.x configuration files for those who have expressed an interest. Also, due to the rather large nozzle, I would suggest that in addition to a moulded nozzle cover, a 50W heater be used. A 40 W heater is very weak. A major shortcoming of this printer design is with its Z axis lift. The two motor system is not mechanically locked together and can easily be skewed thus requiring frequent adjustments. The single 8mm lead screw nut also has quite a bit of backlash. In an effort to overcome these problems I re-designed the X axis end pieces to incorporate a second adjustable lead screw nut. The adjustable nut is set such that (with the screw in place) there is a slight drag on the screw when moved and thus providing anti-backlash. I highly recommend this upgrade. Addendums: 2/8/2020 With the extruder motor slipping and struggling to get enough filament pressure on the Diamond nozzle, I decided to try a geared extruder to increase the torque. I combined the Pitan Geared Extruder (thing:2728600) with the Tevo Tarantula Titan Bowden fitting (thing:2677766). This seems to work very well, so I have added the BOM and stl files for this addition. NOTE: Some stl files may be 10X in size. Also, since I like to print with PETG, I am also adding files to add a part cooling fan to the carriage.