Adafruit Motor Shield v12 for Arduino
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Adafruit Motor Shield v1.2 for Arduino

This is a model of Adafruits Motorsheild v12 it includes most of the bottom features that might be a issue when building a mount or box for it I might go an add more features later but it is relatively complete now ...

similar models —

Adafruit Motor Shield v1.2 for Arduino alternatives
Triple Motor Shield V2 Case
3DPRINTINGWORLD
Arduino UNO case
Tymyn_3D