I love this so much. Such simple machines, for human-scale problems. I often get pulled down rabbit holes of machines and automation - this is a nice reminder that you can solve a lot of problems without reaching for an arduino or a servo.
Awesome solve!!! Lasers and 3d printing is my side hobby business and is what keeps my sanity intact. I love seeing the practical creations that are realized by them! One of my core tenets is being self-sufficient and achieving efficiencies. This post is exactly that. Well done.
>> I have wasted a significant chunk of my life counting out small numbers of parts into bags and posting them to people.
So, small parts like this are always counted by weight, and I'm wondering why you would spend so much time on a counting solution when "buy a scale" is right there.
He's counting out like 6 at a time. He needs a fast way to pick small quantities precisely, not a fast way to check large quantities. Once they're picked they're easily verified by eye.
Up to roughly 100 bills it's pretty much bang on - even with a cheap $10 scale (American Weigh Scales Digital Pocket Scale has a bunch of different options). Each bill weights roughly 1 gram. So - accurate to within 1% - and presumably the banks have better scales.
I suspect at scale (moving either a lot of batches or large batches), you also need to take variance into account more. Some bills might be dirty or have stuff stuck to them, some bills might be damaged and have bits missing? And other things that occur in practice that I can't think of from the comfort of my armchair in 30s.
It wasn't very precise but you could move a lot of money in ball park with this method. Atleast internally across branches.