Single or Multilayer Helix in HO / OO Gauge.
This is 1st / 2nd Radius Track Setup.
If your looking at this you likely don't need instructions. Once you start printing it, it'll become pretty self explanatory. Please use the pictures as a guide for assembly.
I also have a 1st radius single track only Helix which can be found at the link below;
Model Railway HO / OO 1st Radius Single Or Multilayer Helix by Simply Models - MakerWorld