LEGO Duplo compatible train car

Update: some users mention that the studs are too lose and that scaling to 101% fixes the issue. I designed and printed this model a long time ago and adjusted the tolerances for my old printer which was probably not well calibrated. So scaling everything up is most likely a good idea for you ;)

The standard little cars that you get from Lego Duplo have one fatal flaw: they are not compatible with the Duplo train! They run on the tracks but the wheels are too wide and can't pass the switches and get stuck all the time.

Therefore I designed an alternative little Duplo car that works with the train tracks.

You need to print the body and the 4 wheels. If you have a suitable O-ring at 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.

There is also a connecting rod which needs to be printed from high quality PETG since it is prone to breaking. It looks great but I only got one working version so maybe not the first choice for the first test.

If the wheels are not moving freely use a bit of sandpaper and a drop of vegetable oil. This also gets rid of squeeking.

I recommend to print from PETG since it is less brittle and does not produce sharp edges in case something breaks.

I uploaded a short video so you can see the train in action https://youtu.be/1EHsoNpzt5g

There are two versions of the car body included. Both work, just use the one you like better.

All parts should be printed without supports

Category: Toys & Games