Another buffer (RMU inspired)

I finally decided the Prusa buffer wasn't cutting it for me any more and started looking around. I of course found the RMU and it's open source clones which I liked, but had some issues with. My primary issues with one or all are:

• Requires hardware I didn't already have (and didn't want to end up with a bunch of parts I had no other use for).
• Some were complex prints of many parts and/or needed supports.
• They all limited the MMU → Extruder length to roughly the stock Prusa length and I want to move my MMU farther away.

So I looked at it and came up with my own buffer designed in TinkerCAD to solve these issues. At the time of the latest update only the v1 top has been used for a print where it ran for over 4 days with only 2 unload failures.

Required Hardware:

• 10 PC4-M10 passthrough fittings.
• 5 608-2RS bearings
• 2 m3x10 hex head screws
• 4 m3x12 hex head screws
• 4 m3 nuts (I used nylocks, but that shouldn't be required).

Parts to print:

• case - top v2
• case - middle
• case - bottom
• axle rod
• 2x axle end
• 2x latch pin
• 5x wheel

Printing:

• All parts should already be oriented correctly.
• No supports are needed.
• I used PLA with an 0.2mm layer height and 0.4mm nozzle.
• The middle and bottom parts of the case print best with a brim (I used 10mm).
• I ran everything except the case bottom at 200% speed.
• I ran the case bottom at 100% speed for the first 5 layers, 200% up to 20mm, and then 300% for the rest of the print.

Assembly:

• Insert the bearings into the wheels.
• Insert the 10 festos into the case top.
• Insert the wheels into the slots in the case top.
• Insert the axle through the top to secure the wheels.
• Attach the axle ends to the axle with the m3x10 screws.
• Use the m3x12 screws and m3 nuts to secure rear hinge points.
• Insert the latch pins into the front latches.

Things to do:

• I want to release SCAD models for the bottom and middle case parts so users can create custom sized buffers.
• I want to add a new case part that can go between the bottom and middle to modularly extend the case as needed.

Update 06/20/22:

Added “case - top v2” which should replace the v1 version. The v2 version is shortened a bit to reduce the print time and filament requirement. It also has ridges added above the wheels which help properly guide filament when loading the buffer. I haven't run prints through this top yet, but loading is MUCH easier than the first version.