E-Bike Controller Mount for Seat tube

Since I was fed up with turning controllers mounted to my seat tube with somewhat provisoric bottle mount adapters, I designed this mount to be glued to the seat tube. Please understand that is more like a “work in progress” than a finished product.

You will need a controller with two mounting holes on each end. Simply measure the distance between them. After this open up the OpenSCAD file and adjust it to your needings (Variable “length_controller”). Then export to a slicer format of your choice

like STL.

Suggestion for stress-free printing: Face the flat part downward to your print bed. You will most likely get away without any support since the structure doesn´t have much overhang. I would suggest to use a wider brim though to get a flat surface. There are two controllers pre-defined in the OpenSCAD file which are also included as STL.

The first one is a Grinfineon 4825 from Ebikes.ca:
https://www.ebikes.ca/shop/electric-bicycle-parts/controllers/c4825-gr.html

The second one is a 12 FET controller from the german company EBS:
https://www.ebike-solutions.com/de/shop/pedelec-e-bike-teile/controller/ebs-programmierbarer-controller-12-fet.html

For mounting the controller to the adapter itself, you will need two M5 nuts, two M5 washers and two M5x10-12 screws. I used M5x11 Allen key screws which are also used for 3D printers. For the M5 nuts any modell will do but I suggest you use some of those self-securing versions. They are a bit higher but at least the ones I bought fit perfectly

in the hole in the bottom. Prior mounting you e-bike controller you will need to use longer M5 screws plus a big washer and “pull” the nuts in the holes. Work carefully in order not to damage the adapter.

While I have included all “normal” diameters for seat tubes out there I guess the oversized version is the most common measurement.

For attaching both the adapter and you controller to the seat tube I can imagine multiple options. Personally I will use Sikaflex which is marine glue. But something like double sided sticky tape or sealing compound will do. I would not encourage you to use anything more permanent that this like Epoxy in case the adapter ever breaks.

For filament I went with normal PLA and 100% infill. While PLA doesn´t have the best reputation I guess this part will do for an e-bike which is used for recreational riding only. For daily exposure to sunlight and other weather I would go for more resistant stuff: PETG at least or preferable ASA / ABS.