Prusa Mini Dual-Z CK3D mod

UPDATE 22/02/2023 :
* Added an M5 version for z_bottom_left (as it was asked by a member)
* Added my M3 & M5 printable T-nuts for help (print and insert std hex M3/M5 nut)

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I had hard times with banding on all my mini's (have originals and clones), so the ultimate fix was to try stiffer dual-z frame

I didn't want to buy a bear frame and get useless original parts, so I designed this remix requiring minimal parts, stiff enough to delete unwanted moves from the cantilever while printing.

Also the top new extrusion brings opportunities for accessories mounting like top spool holder, camera mount, light mount, raspi box, etc.. it can go faster than original, it can handle easily direct drive mods… 

You will need :

• Nema 17 1.8° stepper L=310mm leadscrew TR8x4 + trapezoidal nut
• new smooth rod D=10mm, L=341mm + LM10LUU bearing
• 2x 3030 square profiles (type-B), M8 central thread onboth end
  (buy threaded or do yourself)
• 4x M8x30 hex screws for extrusions assembly
• lot of M3 fasteners (m3 square nuts, multiples screws m3x8, m3x12, m3x20,etc..)
• Series wiring loom for second stepper (look diagram : buy it or do it yourself)

the belt remain the same lenght as original, doesn,t need remplacement
 

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Recommandations :

2 stls are given for idler : 3mm bore (prusa style) and 5mm bore (gates style) as my actual setup is in 5mm

2 stls are given for z-bottom-left : for M3 screws and M5 screws : it's up to you. My one is M3, but a member asked me for M5 version so it's here.

The new minda holder is mandatory, otherwise the original holder will collide against the new rod..

Sorry for lack of documentation about fasteners, I have big stock and i wasn't worried about that while assembling, so I forgot to notice which screw goes where.. hope I will find time for better documentation later.. nothing difficult to do but you will definitely need several m3 fasteners (hex nuts, square nuts, m3x8, m3x12, m3x20, etc..) ..

I choose series wiring of stepper coils, because it will respect the driver and the steppers current, it's the most important thing. Voltage will be divided by 2 but it has no consequence as z moves are very slow. I do it myself but I know they exist for sale.

I advise not to go parallel wiring, it will double the needed current, and could make unexpected things.

Have fun ^^