April 20, 2026
Description
I'm adding a second BMCU AMS and wanted a hub with the capacity for both sets of AMS tubes and an additional tube for an external roll. I also wanted it to look close to OEM. This reduces the amount of retraction needed for filament changes.
It's important to note! This is a small parts print with tight tolerances. You need to be calibrated, (Temp, Flow Rate, PA, Retraction, Shrinkage, etc.) Or, you may have issue with the parts fitting correctly.
There are two versions:
The first uses locking rings and collets (similar to stock). This is the best version for use on the Toolhead.
The hub also has improved internal geometry to guide the filament better.
Original version - I used the 4 collets from the stock hub and printed the other five. Use a material with good layer adhesion for the collets The locking rings are a mixture of the four from the stock hub and five individual rings from disassembled donor fittings.
All versions require the use of the stock magnet and the locking collar. Magnet orientation is important! If you get a filament error when trying to print, the magnet is installed incorrectly. remove and flip the magnet lengthwise.
Updated Version 4 Hub Cap Assembly-
Insert the “Center collet” last.
Once inserted the collets don't come out easy. It you insert them out of sequence or for some reason want to remove them and reuse the cap, your best option is to cut them up to remove them.
~OR~
Original cap version -
Hub Assembly - skip to step 2 if using the tube version.
Hope you might also find it useful. If you do, please consider giving it a boost. It would be greatly appreciated!
License:
Standard Digital File License