This is the beta release of the new Mini Openbuilds project. Right now I have the prototype fitted to my new Mni 2.0 frame I am building. I have a mini 1.03 in house as well that I am waiting on parts for. Expect pictures of that installation and video of it in operation soon.
This upgrade will fit all current variants of the Mini frame up to Mini 2.04 It fits within the stock space claim of the existing mini bed and gives you 1mm additional Z travel. It also increases the rail stiffness and frame stiffness considerably, and allows for much faster carriage movement. The wheels also weigh slightly less than the Igus bearing assembly blocks so you end up removing a bit of mass from the bed. This upgrade is intended for those seeking faster print speeds and minor quality improvements. The stock Mini rod span is short enough I don't expect this will result in a noticeable improvement in quality, but you should be able to push your mini to 133mm / sec speeds in Y, with a similar increase once the X axis files are released. This may however improve quality for anyone printing very small, very high detail items such as figurines or jewelry on the Mini.
Bill of Materials:
4 Openbuilds Xtreme Delrin wheels https://openbuildspartstore.com/xtreme-solid-v-wheel-kit/
2 6mm spacers https://openbuildspartstore.com/aluminum-spacers-10-pack/
2 6mm eccentric spacers https://openbuildspartstore.com/eccentric-spacer/
4 30mm Low profile M5 bolts https://openbuildspartstore.com/low-profile-screws-m5-10-pack/
2 500mm 20mm x 20mm Openbuilds Vslot extrusions (cut to length, the 250mm ones are too short - Final cut length TBA) https://openbuildspartstore.com/v-slot-20x20-linear-rail/
4 M5 14mm Cap head bolts
15 M3 heat set inserts https://www.mcmaster.com/94459a130
1 12mm M4 cap head bolt, nut and washer
2 non-threaded 1/4" spacers 1/2" long
2 M3 washers
2 m3 16mm Cap head bolts
4 m2 heat set inserts https://www.mcmaster.com/94459a110
The stock Mini frame, mounting bolts idler hardware and belt pieces
4x m4 12mm bolts and nuts to hold the drill guide in place
Drill bits 5.0mm and 7.2mm for the bed. https://www.mcmaster.com/30565a272 and https://www.mcmaster.com/30565a296
Instructions: Print all pieces. Install the Heat set inserts in the Idler body, cable chain offsets, belt / endstop mount and the motor and idler end main pieces. Dismount all hardware from the stock bed and mount the drill guide to the bed using temporary m4 bolts and nuts. Check alignment using a square. Now drill the 7.2mm and 5.0mm holes using specialty drillbits from Mcmaster Carr. Remount all the bed hardware and bolt everything together.