Large building bricks compatible train car

thingiverse

The standard little cars that come with Lego Duplo have a major drawback: they're not compatible with the Duplo train! They run on the tracks but their wheels are too wide and can't navigate the switches, getting stuck all the time. To solve this problem, I designed an alternative little Duplo car that works seamlessly with the train tracks. To build it, you'll need to print the body and four wheels. If you have a suitable O-ring on hand, push it over the wheels; I used a 20x27x3.5mm O-Ring, but you can also print the included O-ring file from flexible filament. A connecting rod needs to be printed from high-quality PETG since it's prone to breaking. It looks great, but I only got one working version, so maybe it's not the best choice for your first test. If the wheels aren't moving freely, use a bit of sandpaper and a drop of vegetable oil; this will also get rid of any squeaking sounds. I recommend printing from PETG since it's less brittle and doesn't produce sharp edges if something breaks. You can see the train in action in a short video I uploaded: https://youtu.be/1EHsoNpzt5g There are two versions of the car body included; both work, just use the one you prefer. All parts should be printed without supports.