gears and cogs
thingiverse
You can get a variety of small miscellaneous gears and cogs that work with DC motors or servos. Simply drill your own holes into the middle to achieve the perfect fit for what you're trying to attach them to. The dimensions are clearly shown in the accompanying pictures. If you need custom-made ones, don't hesitate to ask!
Download Model from thingiverse
With this file you will be able to print gears and cogs 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 gears and cogs.