How to draft without a reference item.
Hello I would like to 3D-print a football helmet. I found some helmets here on GrabCAD, but that doesn't help me learn. How would you model something when you don't have it in front of you to get dimensions and the likes from?
Photographs will help with creating the model.
If the scale is important, then make sure to correctly scale the photo before starting.
Another option is to download a helmet that was made in Autodesk Inventor. I assume it has a feature tree like SolidWorks, and you'd be able to examine how the helmet was made step by step.
Another option is YouTube. There are a few helmet tutorials you could watch which would get you started in the right direction.
1. Get a picture(normal view) of what you want to model/ make a rough diagram on a piece of paper.
2. Use a ruler and using the picture/ diagram fix a scale.
3. Start imagining and modeling you will make something good out of nothing.
.... That's what I do...Good Luck