BLV 6mm Gates XY and 3xSFU1204 kinematic leveling Z motion system for BLV MGN Cube

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CAUTION! I designed the parts for being printed in MJF i.e. high accuracy and tight tolerances. EDIT-24.12.2021 added a .step file for a matching mod of the EVA extruder. For the mod I got rid of the belt tensioners, since we already have a pair, adjusted belt positions, fitted an Orbiter v1.5 and an optical x-endstop and fixed some design flaws of the original EVA design. EDIT-24.12.2020 HAD EVERYTHING PRINTED AND ASSEMBLED IT Reworked a few clearances that were to loose, making it harder to assemble stuff (no big deal tho if you already assembled everything) The keyhole in the left motor bracket was only in the bottom part and had to be drilled out in the top part. Fixed that now EDIT-19.08.2020 moved the motor positions for the X and Y slightly to the center, so that the steppers won't touch the frame (Michaels noise problems in the group made me a bit paranoid...) now the steppers can be as big as 43x43mm before touching the frame. Made two parts out of the one bulky Z-Motor/BK10 mount, for better flexibility (e.g. different ballscrew end dimensions) and for better realignment of bearing block, ballscrew axis and z motor. Also they will now be cheaper to manufacture if you want them to be SLS/MJF printed. EDIT-20.06.2020 repaired 3 misaligned holes in the right motor block top part. Thanks @Guru54321 Unified naming of the parts (BIG ONE) added my take on the kinematic leveling tripple z motion system using SFU1204 ballscrews and updated thing name, sources and pictures accordingly. EDIT-20.05.2020 Updated the tolerances for where two parts meet and where bearings and nuts are inserted (mostly 0.15mm) and the screw positions on the rear corners This is my take on the BLV MGN cube motion system! For Z I chose a tripple Z setup using SFU1204 ballscrews and standard BK/BF10 bearing blocks. I am using a kinematic leveling system using magnets (for size reference of these please check the step file, I ordered them from www.supermagnete.de and the magnetic balls will be sth. like Haydns Magballs) The heatbed is a custom milled 385x385mm plate and 350x350 keenovo heater in a sandwich design as recomended by keenovo and it does not need the frame beneath the bed because the magnetic balls will screw directly into the heatbed assembly. (Note that I extended the frame 100mm in Y direction and shortened the electronics compartment in the back from 80 to 60mm for this bed size) I made sure the nozzle would be able to hit the bed (without the frame beneath it the bed sits quite a bit lower) with the popular Helmet extruder and with an Hermera tool for the tool changer. This is why the carriers for the SFU1204 z nuts have that trunk looking part extending to the top. For XY I made a remix of yuris 9mm belt upgrade for the BLV mgn cube to fit 6mm belts and idlers. You might ask "why would you do that since the original design already is made for 6mm belts?" The answers are 1. I found the belt paths in Ben's original design are not parallel to the axis (I don't know if this will improve anything besides not triggering my OCD) 2. I wanted to use genuine Gates idlers (purchased from e3d for quality and reliably accurate dimensions) instead of flanged bearings, because even if you flip the belts in the rear, in the front tensioners there will still run belt teeth over a smooth bearing surface. 3. I wanted to use shoulder bolts through the idlers because running bearings on a screw as a shaft isn't the proper way (hence Yuri's design) 4. I wanted to support the motor shaft on both sides (in the motor and beyond the pulley) so that the belt-tension-force does not pull on a cantilevered motor shaft pulling it out of it's right angle. If this persists over time, the plastic will creep and the motor will sit slanted on the part even with no force that pulls on the shaft. 5. For maximum compatibility with future upgrades along the way (e.g. tool changer) I wanted the belts and pulleys to be contained in the upper 20mm of the frame (within the top most extrusion). 6. I wanted to use the Front tensioners for the looks I would have loved to use 9mm belts because of the higher resistance to stretching and just for the purpose of overbuilding the machine but especially point 4 and 5 are hard to obtain if not impossible with 9mm belts. Also I have not seen any evidence so for visibly improved print quality with 9mm belts so far. I won't list every single screw since the design is based on yuri's design but some things are different: Instead of the shoulder bolts of the 9mm belt upgrade you will need something like this: 10x ISO 7379-5-M4-30 2x ISO 7379-5-M4-16 (https://www.ganternorm.com/de/produkte/3.2-Befestigen-Positionieren-Nivellieren-mit-Schraub-Klemm-und-Auflageelementen/Augenschrauben-Passschrauben-Druckschrauben/ISO-7379-Passschrauben) You will also need the shim washers (https://www.filastruder.com/products/shims-for-shoulder-screws?_pos=2&_sid=c453a62c8&_ss=r&variant=17989593104455) and the same amount of pulleys and idlers (only in the 6mm version of course) but not the standard M5 washers. The shims will directly contact the printed part; for that matter the bore diameter for the shoulder bolts has been reduced from 5,5 to 5,1mm (you might drill that out if it does not fit) You will also need all the screws to attach the parts to the frame (mostly DIN912 M5x10) and the extra hardware for the tensioner (chances are you might already have that one)

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