MMU Slot Buffer Symmetrical and transparent slot remix by lukemcn

Last crawled date: 3 years ago

Remix of Martin Jerabek's MMU Buffer: https://www.thingiverse.com/thing:4311235
I needed to fit an MK3, MMU2S, buffer and 5 filament reels inside the space of a small double wardrobe.
For a compact space I found Martin's design by far the best and most robust approach.
To achieve this I modified the original 'bottom' piece to be more symmetrical allowing both top and bottom to be used for slot access simultaneously. By fitting the unit rotated 90 degrees so slot access is both east and west (for a south heading printer) give me more flexibility where filament reels can be placed in tight space - in my case filaments where placed radially around the buffer, north of the printer. All fitting in about half the volume of a double wardrobe.
This of course, creates redundant 'slots' for any 5 filament setup (as every slot can be accessed from both sides) but is an acceptable if not desirable feature given the fitting flexibility.
Additionally, I wanted to see the physical state of each buffered filament for debug and aesthetics and had a load of thin clear plastic sheets laying around so created a slot divider that integrates with a plastic sheet to create transparent slots.
Some more info on operation and constraints: https://twitter.com/lukemcneice/status/1349655044581449730?s=20
-Symmetrical filament access-
Most of the parts you need for a full build are from the original MMU Slot buffer but there are changes to major parts and how its constructed.
Please inspect Martin's original overview drawings in PDF first.
The main change is that I replaced (thus, no need to print) SBU_bottom and require a number of his original parts to complete the replacement.
Specifically, In place of the (original) SBU_bottom you should now print:
2 X (the remixed) SBU_Bottom_symetrical
2 X (original) SBU_Side
4 X (original) SBU_F.Slot-(your preference)
2 X (original) SBU_Front
These above parts (aside from the original SBU_bottom, now being replaced) are additional to any parts the SBU MMU Buffer requires.
-Transparent Dividers-
This remix can still be used with the original dividers. The SBU_Divider_acetate are not perfect but where functional enough for me thus may require modification depending on what resources (sheet thickness) you have available.
The SBU_Divider_acetate is based on a 200 micron thick PVC/acetate sheet that I cut to size manually (168.00 X 205.00). I used these: https://www.amazon.co.uk/gp/product/B000TK89A4/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1
The design was intended to use a hole punched in each corner of the sheet to fit around a locator pin in the divider with a push-fit clip that kept it from falling out but this locator pin approach made alignment very sensitive to any positioning error in the sheet's hole.
After a couple of attempts I ended up cutting off the sheet's corners - enough to not overlap with the dividers locator pin but still sit on it's shelf. I then just superglued the clip and sheet before clamping them to dry. Beware that if you also take this approach that any (invisible) air gaps between the plastic sheet and the divider will create a capillary effect that will draw glue out to the window that's difficult to see until it's dried (and ugly) - use glue sparingly.