Low cost 35mm negative digitalizer

Hi everyone!
I decided to upload this first project of mine on thingiverse for anyone who is into analog film photography or also for anyone who just have some old film at home and wants to discover what photographies are hidden in them.

Since scanning a 35mm film in a photography shop or laboratory can be VERY expensive, I tried to create a setup to scan photographs on your own with just a digital camera. On the internet you can find a lot of tutorials about scanning negatives with DSLR or digital cameras. Basic principle is to make a high quality photo to the negative and then reverse the colours with Lightroom or Photoshop. Some example tutorials can be find here:
https://www.diyphotography.net/scanning-film-negatives-with-a-dslr/
or this one:
https://petapixel.com/2012/12/24/how-to-scan-your-film-using-a-digital-camera-and-macro-lens/.
Here I tried to create a cheap, simple and practical setup to do the scanning process without the use of expensive negative lightboxes.