I purchased a really cheap Nikon 28-80 Lens for about 35 $ but it came without a cap and I wanted to keep it for a while. I checked e-bay and you could only buy four caps for 8$ so having a 3D printer I decided to design and print a cap and save the money and waiting for delivery.

Took about 2 hours total to design and about 4 more to print.

Take a look at the photos and the video I am going to attach and I will also attach the STL files below if you want to print it yourself.