Toy Train

This is my design of a simple toy train.
I've put an electric motor, some gears, a 18650 battery and a charge controller inside, for my child to play with.
The design was done in a free online 3d workspace called Onshape.
Here's a link to my project, feel free edit and redesign to your own need.
This was design with 3D printing in mind, the train consists of 10 parts, those were designed separately, for the ease of printing.
The lower part of the body has 2 variants. One is slightly bent to compensate for the top part deformation while printing. And the one without deformation.
The deformation usually occurs when printing a top part on a cheap 3D printer, where the corners would unstick from 3D printer's bed and warp upwards. If you have a closed temperature controlled camera you'll need a regular lower part of the train.

https://cad.onshape.com/documents/ff272b26a94038ae1fd3b3f6/w/412f94d033a251437fa1470b/e/2e41d646317b63f56fb513b8