Wooden train (Brio, IKEA...) to Duplo adapters (minimal material design)

Want to reuse toys you already have in a new way. Why not challenge your fantasy by making gigantic bridges and ramps with wooden trains (like Brio or IKEA) with help of simple Duplo bricks. These adapters will make this happen!

I got inspired by similar designs on the web, but they were too bulky and often even needed support. I designed this here fully from scratch, since the original (and any others I saw) seemed to be quite excessive on material use and not fully compatible with all rails around. Here are the improvements in my design:

• compatible with Brio and (!) IKEA (and most likely other similar trains sets)
• less material (about 50% only) and faster print (almost twice as fast) with same functionality
• based on 2x2 Duplo brick instead of 2x4
• reduced rail depth to 2.5mm (instead of 3mm), which improves wheel traction significantly (long story and many experiments, seems to work flawless)
• I even experimented with using a Duplo buildplate and made 2 versions to allow an even distance bridging matching Duplo standards:

1. Short: Most minimalist design, but cannot bridge 2 columns fixed on a single Duplo build plate (1/2 a pin too short)
2. Not-short: Half a Duplo pin longer, so can bridge 2 columns on a single plate (of course that can still depend on the brand and length of straight connector you use, but one of the 2 versions should work either way)

Print instructions

It prints without support and with minimal material settings, since not much strength is required: I used 0.2mm layer height, 2 walls, 5% infill

May 2024 UPDATE: 

I overhauled the Duplo base design so it requires no in-build support anymore! Some parts also had an outdated "Brio-pin" design, which was not loosely compatible with other brands - that should be fixed now!