Brio Wooden Train Tunnel

I wasn't quite happy with all the existing options so I took ideas from several places and put them together to make just what I was looking for. I hope it fits your needs as well!

I designed these to fit my Brio and compatible tracks, so I can't promise they will fit every brand of track out there, but they do fit Brio.

I designed it to be the same length as the straight “long” brio tracks (216mm). It could be shortened to the standard length straight track pretty easily if desired. Standard tunnel height so any train should fit through. I added the flat spot in the middle so that elevated track could go over it like a bridge. I made it wide enough that you can even have a second tunnel going over the top.

I recommend using my gcode files if you have a mk3, or use my 3mf file to modify for other printers. I optimized everything for a fast print (0.3mm layers) and added pads to help limit warping. No supports needed, but the bridging at the top is pretty long so expect a few strings at the ends that need to be trimmed off after print. I also did a color change to use my wood colored filament for the bottom and a sparkly purple for the top. Both my print files below include that color change so remove it if you don't want it.

I used “Polymaker Matte PLA Filament - Peanut Brown - PolyTerra Filament” for the bottom and I've found that it's almost a perfect color match to the brio tracks. One disclaimer, the spool I got is a bit out of spec and I get over extrusion if I don't pull the extrusion multiplier down a bit.

https://www.amazon.com/dp/B094FDSQHC?psc=1&ref=ppx_yo2_dt_b_product_details