A small gear broke inside the blender Kenwood HB723 blender. I designed a replacement and printed in PETG. Already tested already for several weeks. Here you can see a video: https://youtu.be/hD8TeM7rfVg
I assume that it is the same design used for the newer HDP 408WH.
To open the blender top part you need a flat screwdriver and some brute force. Unfortunatly both parts are glued or melted at some points together. To assemble it I used a Dremel and PLA to fuse the two parts together at a few points. (Epoxy glue failed)