Low Friction Filament Dry Box with Magnetic Rewind Feature

I print a lot of PETG and TPU, but I couldn't find something quite like what I needed so I took a bunch of other ideas, chopped them up into little bits, seasoned liberally with magnets, and somehow managed to create something useful in the process.

Things I needed:

• Low Friction
• Front Feeding
• Fast drying / long-term storage
• Easy rewind (while avoiding additional use-time friction)
• Cap storage while in use
• Filament holder that doesn't disintegrate on touch, loose gripping power, or refuses to release.
• Relatively low cost compared to other solutions.

Things I didn't need:

• PTFE Tubing
• Bearings (actually tended to increase friction and cost substantially if you purchased quality ones over an all plastic solution).
• Difficult to print components with high failure rates.

Found a lot of the solutions liked to have very thin parts that would either need to be printed laying down then assembled using screws or would just outright fail as they were too tall/slim for tougher materials like PETG. Also very few of them had a rewind feature, and those that did added far too much additional friction while printing.

Decided on a simple 2 part magnetic axel. To keep things cheaper each box only requires 8 10x1mm round magnets while the handle (a one time cost) is setup for 8 10x5mm rounds (I usually just stack 5 of the 1mm in each slot).

But you say, I've tried magnetic solutions and they all suck at providing any torque, solution; by alternating the magnets polarity it basically turns it a solid state motor reducing gear slippage with both push and pull tightly gripping the axel.

I also found I wasn't able to use most PETG right out of the box without pre-drying, and I figured that area inside the spool was just a complete waste of space going unused. So I adapted Malolos desiccant containers to provide a little boost. Most PETG tends to arrive between 25-35% humidity out of the box, the old boxes would take days to drop it on it's own, with the additional 45g of desiccant in the spool these drop the air down inside the box to under 10% over a few hours.

I then adapted the same desiccant containers to original bottom-insert formfactor, adjusting the height, while maintaining the original capacity, to avoid interfering with the spool if it were slightly bent (I hate cardboard spools). Malolos containers print significantly more reliably than the original thin ones, and generally don't crush as easily when removing.

I found all of the cap designs to be just dreadful, had too many of them drop behind my desk while printing, so I modified the standard knurled cap to have a nice little flexible attachment to the feed through. I also despised the little brittle filament holders so I made a nice little passthrough one out of TPU (I mass print a bunch at a time usually), this also allows the cap to rotate freely while still keeping the freshness in.

I attached all the exterior pieces using clear double sided Gorilla Tape instead of using hot-glue as I just found it easier to work with and cleaner. I cut the tape using a sharp work knife on a craft cutting board then attach to the various parts using tweezers trying not to touch the sticky side with my fingers as the grease and sweat tend to mess up it's adhesive qualities.

10mm magnets I used:

• https://www.amazon.ca/dp/B0965QMQMS?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_2
• https://www.aliexpress.com/item/1005006190829397.html?spm=a2g0o.order_list.order_list_main.73.65561802BnfelC

Storage containers I used:

• https://www.amazon.ca/dp/B08TWH2QHV?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_1&th=1
• https://www.amazon.ca/dp/B07NP98YKY?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_3&th=1

Double Sided Mounting Tape:

• https://www.amazon.ca/dp/B07LFRN1K8?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_1

There's a couple different companies who re-sell the same ones, I usually just check them all and find whichever one has the lowest per-unit price.

My design work is a bit of a mess as I've been out of the game addressing serious personal health issues for far too long (Doctors are idiots… nurses are amazing though). I had hoped to have the whole thing redesigned nicely in a parametric format with nice parameters to adjust for other spool styles, but ran out of time. So I'll release it as is, warts and all.

Love it, hate it… take what you can, leave the rest.

Note: Seems I'm limited to only 1 licensing option, guess one or more of the the original models was a bit more restrictive for commercial use.

PS: For easy printing, suggest using Orca Slicer and opening the “all_in_one_buildplate_orca.3mf” file, has everything laid out and orientated for easy printing.

Sliced, diced, and fused several other amazing box designs into a single low friction, lower cost solution, now with magnets!