Passive Rewind - Medicine Box Version

2026.4.09 As per comment request, added the feeder tube inlet version Theoretically, it can reduce filament jams like the ceramic feeder inlet (not actually tested) Those without a ceramic ring can try it

2025.11.17 The ceramic feeder inlet was lowered by 3mm (tested) If the filament sinkage rate is high, a 2.0 wrench can be used to clear the feeder inlet

Modified a widened outer plate for cardboard spools and narrow spools, effectively reducing rewind resistance (modified fromLatest Spool - Material consumption tray with scale lines from Luying 3D Printing MakerWorld: Free 3D Models Download)

2025.11.10 Updated the ceramic feeder inlet version and some minor optimizations

Extra large dryer box (120mm x 120mm Desiccant Box from Atelier_Riki MakerWorld: Free 3D Models Download)

Ceramic eye dimensions: small outer diameter 3.8 inner diameter 2.2 length 6 (small outer diameter just needs to fit length doesn't matter)

Miniaturized passive rewind, suitable for medicine box passive rewind, connect multiple BMCUs for 16-color filament selection

Reduced and lowered the active wheel, also reduced the passive wheel to keep the overall height around 210, just enough to fit into the medicine box, considered a passive rewind solution with smaller space occupation

4 passive rewinds are connected together using M2 self-tapping screws through the screw holes on the side, then placed into the medicine box You need to drill 6mm holes yourself at the corresponding positions on the medicine box, and 6*4 through-hole silicone protection plugs can be used for sealing Use 3 desiccant boxes (https://makerworld.com.cn/zh/models/612854) to keep the filament dry, and also just jam the front and rear gaps

The original Bowden head has been replaced with through-hole M6 pneumatic connectors The overall assembly method is basically consistent with the original version, just refer to the original version

Plate 2 is a spare part and does not need to be printed

Note: For narrow spools (such as Caige), 1.1kg spools (such as Jayo), and paper spools (such as R3D), there is greater resistance when rewinding, with a small chance of filament jams For this, a 50 diameter passive wheel was made The large wheel version needs to be placed on both sides of the medicine box Even with the large wheel version, it's best to try and avoid using these types of spools

Differences from the original parts are as follows

M2*6mm self-tapping screws 20

M3 *12mm countersunk screws 20 (countersunk)

M3 *18mm countersunk screws 20 (countersunk)

M3 *35mm large flat head screws 4 (If not using M3 heat set inserts, appropriately lengthen to 45-50)

0.5*6*50 spring (cut for use) 1

22*3.5 O-rings 8 (outer diameter 22)

608 bearings 20

8*80mm smooth shafts (80-87mm are fine) 4

HF081412 one-way bearings 4

PC4-M6 pneumatic tube connectors 4

One elastic band with 28mm inner diameter (cut as needed)

When debugging, make sure the spring is not too tight just a little pressure is enough

If the one-way bearing is too tight you can heat it slightly and then rotate it