/3/ - 3DCG

Here's a great site for people that want to use real-world dimensions, but have trouble finding them for random objects.
https://www.dimensions.com/

It's in the pastebin, and I've been using it for a while, but I don't think it was ever mentioned in any of the threads.
It's pretty useful to find some rough/basic dimensions at a glance when making objects. It's not a blueprint site and it doesn't give you every little measurement, but it's perfect for getting the right scale for things so you can keep things consistent in your scene, or build a library of objects.