A housing I made for my e-bike controller.

Fits a 54x31mm controller 308mm total height, but is printed in 2 pieces for ease of printing and ease of mounting. You need 38mm of space between your downtube and fender/wheel to fit it.

I attached my fusion360 project file so you may change dimensions to fit your bike/controller.

Before using, please check your controller does not get too hot, as it might melt your plastic. For me it doesn't, so PLA is fine for my use.