Filament Storage and Feed System - Wall Mounted

This system I've been using for over a year and works a treat. Easy to swap out filament, see what is remaining and sort issues. You can use this in 2 ways, a way to store filament as its easy if you have the wall space but no shelves (but the filament isn't bagged). Or to use it to feed your printer/MMU.

Before you go further, I did cover a section of my wall in plywood to have the ease of changing mount placement without drilling loads of holes in my wall! Also, if you have plaster board/dry walls I don't think this is for you.

So I have the system hooked up to a MMU2s via Prusa's buffer but you can have it setup for anything I guess, depending on the filament feed direction to you printer (if it isn't a Mk3).
There are 2 types of mount for the filament spools, both use standard 15mm copper pipe (as its easy to obtain from DIY stores and stiff enough for this application). One for standard 500-1000gram spools and a heavy duty version I use for 3kg and upwards. The latter I also print in PC.
For the larger spools, as they take more effort to unwind given their weight, I have made eccentric rollers using 2x 6806 (30 x 47 x 7mm) bearings - or as some cyclists will know them as BB30 bearings. Quite cheap and easy to get again. I went for the eccentric design so the weight of the spool always pushes the bearing downwards and stabilises itself. Very easy to rotate! The little push-fit pieces have a hole for a M3 bolt (Prusa size) which expands, securing itself onto the bearing. 
To keep the spools safe now that they can easily rotate is a expanding wedge style lever that sits in the end of the pipe. Again, M3 bolt needed for that - roughly 30mm long. 

Then theres an offset guide, this is to separate the filament as it travels to the buffer. It is offset from the wall to aid pulling the filament off the spool from more of a central position. Also minimises the way some spools like to walk around on a holder while printing. Its designed to have short (15mm or so) pieces of PTFE tubing clamped in place, again to minimise resistance on the filament. 

Lastly theres a small bracket to fix the Buffer onto the wall. Just remove the nuts from the back and the bolts screw directly into the bracket. The file named Buffer spacer is optional, but just a small spacer for the bottom of the buffer now that we've spaced the top away from the wall. 

Notes:
Copper pipe doesn't need to be longer than 130mm per holder, but do check the width of your spools before cutting - would also recommend using a pipe cutter or roller as you wont need to file the ends etc. Nice and clean!
Screws for all the mounts - whole diameter is 4mm and counter sunk. Plenty for general use screws. 
Tightening the expander wedge bolt - this doesn't need to be very tight! keep feeling the resistance needed to rotate the lever, it doesn't require much. 

Happy printing!