mag_block_gear_adapter
thingiverse
Combine up to three sets using this magnetic adapter block! The block is compatible with large stud-style blocks (e.g., duplo, megabloks), magnetic blocks (plastic, or wooden magnet blocks: e.g., tegu), and pin-style gear sets (some random gear toy I bought off amazon). 12x3mm neodymium magnets (common in amazon) is built in *during* printing (Please see the print section on how to embed magnets), so it'll be difficult to get it out without some effort and tools (by design, to avoid accidental misplacement of magnets). Don't have any magnetic toys to play with? You can print this: 6-sided blocks (https://www.thingiverse.com/thing:3977561) Gears (https://www.thingiverse.com/thing:3939688)
With this file you will be able to print mag_block_gear_adapter with your 3D printer. Click on the button and save the file on your computer to work, edit or customize your design. You can also find more 3D designs for printers on mag_block_gear_adapter.