I want to draw a saxophone using the software SolidWorks, but I don't need her dimensions. Somebody know that?
How about downloading this one from the library? SAXOPHONE
It should have some dimensions to get started with.
Two other options I can think of are to:
Measure a saxophone that you have access to.
Use online image searches. You'd have to scale them based on some known dimension, but that is how many of the car and plane models on this site are created.