LEGO Duplo train battery door

thingiverse

I previously downloaded a model from Thingiverse that wasn't quite right for my project, so I designed one from scratch and printed it out. It took some time to get it just right because the battery door has lots of tiny edges, but ultimately it worked out well. To make this design more robust, I added thicker battery separators to give me a bit more material to work with, and I also made the outer shell thicker to avoid printing a 0.5mm layer. As a result, the door now stands off from the rest of the part a bit, but it's much sturdier. If you prefer a thinner shell, you can simply slice that part down without affecting how well the other pieces fit together.