No need to download the software - it's all cloud based. Then it's free as long as you don't mind your files being public. If you are a hobbyist and you register for Onshape, register as an educator - that's what they expect - sort of a 'self-educator'. Printatrak curve underside by race runner, on Flickr Printatrak curve top by race runner, on Flickr Change the 2 numbers and the model regenerates - save as an stl file - slice it - print it! You can alter the design by editing the inside radius and swept angle e.g. Printatrak straight underside by race runner, on Flickr Printatrak straight top by race runner, on Flickr
You can alter the design by changing one number to produce whatever length you want - anything over 40 mm. Both models are Scalextric compatible in terms of slot centres and tab holes, and are designed for copper adhesive tape. So far Printatrak consists of 2 models on CAD. Would you like to 3D print your own track pieces to whatever length, radius or swept angle you like? Now you can with Printatrak.