Prusa i3 Dual/Single Spool Upgrade by dan0h

Last crawled date: 3 years ago

While the factory Prusa i3 MK2 Spool Holder uprights are a nice design and pretty strong, the way they hold on to the spool is less than sufficient and really didn't fill me with any confidence that 1kg of filament wouldn't come crashing down onto my print bed, mid print. With this in mind I wanted to keep the original uprights but utilise them in a better way to give some security, and allow them to store two spools at once, as I like to keep a "Draft" filament, and a "Production" filament together on my machine, to make swaps quicker and easier.
You can use this design to make either an upgraded dual spool holder, or optionally a single spool holder, as such when using it as a single holder, you'll find that one side of the spool has a flange, while the other does not - so it doesn't look as pretty - if there is any demand I will upload a single spool with flanges on each end to make it more pleasing to the eye (this will likely be in two pieces to save complication with supports). Printed in PLA the spool tubes are sufficiently smooth to allow the filament roll to rotate easily, though at some stage I may upgrade it to roller bearing though I do generally regard this as somewhat of an overkill as the feeder has more than enough power to pull the roll without any issues.
To make this design you will need:
2 x Original Prusa i3 Mk2 filament holder uprights.
1 x M8 Threaded bar - 300mm for dual spool, 180mm for single.
3 x M8 Plain nuts (13mm).
Printed parts:
1 or 2 x Spool Tubes.
1 x Spacer (ONLY if using two spools)
3 x Nut Holder
Print the parts as orientated, but use supports for the spacer and the nut holder, the contact areas will need to be smoothed afterwards to ensure a nice finish. I used Slic3r to produce my GCode, so milage with other slicers may vary on ease of support removal. Once printed, take the threaded bar and 2x M8 nuts, wind them together to drive the captive nut into the nut holder, then repeat for the other two nut holders.
Order of assembly left to right for single spool:
M8 Bar / Nut Holder + Nut Holder (wound together to act as a lock) / Prusa Upright / Spool Tube / Prusa Upright / Nut Holder
Order of assembly left to right for dual spool:
M8 Bar / Nut Holder + Nut Holder (would together to act as a lock) / Prusa Upright / Spool Tube / Spacer / Spool Tube / Prusa Upright / Nut Holder
Optionally the spacer can be glued in to place on one or both of the holders, or allowed to rotate freely, though this does make loading the filament a little more of a challenge for dual - I find it easier to build it up off the machine, then attach it with the filament attached, all ready to go. Quick sunday afternoon redesign, I hope it helps secure someones filament! :)