train chassis for Lego Classic car body and Brio/Plarail tracks

This is a remix of Duplo/Brio Car (for Wooden Train Tracks) by timqui.

Inspired by the idea of combining Lego bricks and rails from other makers, I designed this model making some modification to the original model.

1.  Instead of Lego Duplo, this model is designed for car body made with Lego Classic bricks.
2. This model doesn't have any stads. It holds a brick it self, and there is less needs of calibration when printing. (See usage below)
3. Couplers are added so that you can connect cars. The coupler is compatible with Plarail trains. To pull the car by Brio train, you may need to attach some magnet or steel plate on the coupler, which I haven't tested yet.

The wheels are common to the original model.

usage: Attach a 2x4 block on the bottom of the car body, and simply place it on the hole of the chassis. Instead of a 2x4 block, you can also use two 2x4 plates (with one-third thickness of a block) to fix the car body on the chassis. Attach one plate on the bottom of the car body, and bind the chassis by the plate and the other plate.

I printed the model with PLA fillament, 0.2 mm layer height, and no support.
perimeter ≥ 3 is recommended to solidify the coupler part (2023-3-11).

update:
(2023-3-11) The shape of the coupler has been slightly changed to make it less prone to breakage. gcode files were added.