BLV Cube Kinematic three z-axis support assembly for active bed leveling

thingiverse

The goal is to detail a kinematic support solution for a three stepper active bed leveling package for the BLV cube. The Duet fully supports three z-axis steppers, and documentation can be found here - https://duet3d.dozuki.com/Wiki/Bed_levelling_using_multiple_independent_Z_motors. **UPDATE - SEPTEMBER 26, 2019** Oops - I had to update the config zip file. Sorry about that. **UPDATE - SEPTEMBER 25, 2019** Project done! Printer is operational and concept moves from design to complete. I've modified the design since the last time - I've simplified the connections, and also included the config files I use, (and this is critical) for use with the upcoming RRF firmware 3. If you're on Duet firmware 2.x, then you can extrapolate the settings easily enough. Included is an image of how my dimensions to the leadscrews, which are needed to configure things, but note that it may vary for your defined origin. It should serve as a starting point though. The ball ends I ended up using are easily found delta effector ball ends. Below is a link to the ones I used from filastruder.com - https://www.filastruder.com/products/6-spare-magballs-for-delta-smart-effector Also note the 2020 bed needed is comprised of two(2) 2020 extrusions that are 220mm in length, and two(2) 2020 extrusions 385mm in length. **UPDATE - August 20, 2019** After building and mocking up things, I made three parts both easier to print, as well as resolve some collisions that were likely to happen. The choice was to lower the mounts, thereby reducing the build volume, or make bigger changes. I decided to make the bigger changes. Since the extrusions lengths / bed supports were going to be different than the original BLV design, I decided to make the change in the extrusions, and actually gain some more build volume. Three printed parts change (top bracket, and the ball/rod support points), and the extruded lengths needed are now two(2) 2020 extrusions that are 220mm in length, and two(2) 2020 extrusions 385mm in length. The overall volume actually goes up, since I can tuck the z-height up more than before. Note that you need to print one of the rod supports and two of the ball supports. Parts : 8mm Magnetic balls (can use standard ball bearings, but highly recommend pre-tension springs) - https://www.kjmagnetics.com/proddetail.asp?prod=S5 or https://us.misumi-ec.com/vona2/detail/221005686943/?PNSearch=NB005&HissuCode=NB005&searchFlow=suggest2products&Keyword=NB005 threaded rod bearing seats. - https://www.amazon.com/Uxcell-a16050300ux0563-Connector-Stainless-Threaded/dp/B01HSTUZW8/ref=pd_rhf_se_p_img_11?_encoding=UTF8&psc=1&refRID=Q3VFXP7T96KGX98F58DJ Pillow block bearings : https://www.amazon.com/gp/product/B07K7D8DBG/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1 Pre-tension springs : https://us.misumi-ec.com/vona2/detail/110300266030/?PNSearch=AUS6-20&HissuCode=AUS6-20&searchFlow=suggest2products&Keyword=AUS6-20