A small collection of tracks I modeled as a present. They should fit an Thomas the Tank engine track set but I've only tested it on one.

Includes:
1 straight section
1 flex section
2 three way forks
1 intersection

Print instructions

For the flexible track make sure you have the temperature and retractions dialed so that you have no stringing otherwise the piece will bind up a bit. I used PETG as it would likely handle wear and tear better. Only had two break so far and both were due to excess abuse (as a toddler is expected to do).