This one started as a daft idea and turned into one of my favourite things I have built. I wanted a real claw machine, and I wanted to be able to play it when I was nowhere near it.
It works, and the video above is it working. You can drive the claw from anywhere, watch the cabinet through a camera inside it, and find out whether you actually won.
Buying a claw machine in two halves
The gantry, which is the part that actually moves the claw, came from Alibaba. The cabinet came from an arcade dealer: a secondhand Crazy Toy 2 shell sitting in a warehouse next to a Boxer machine and a row of racing cabinets.
Buying the halves separately is cheaper than buying a working machine, and it means the inside is yours to do what you like with. It also means nothing is guaranteed to agree with anything else, which is where the fun starts.
The manual is the interesting part
The brain of the thing is an XK-06 control board, and it arrives with a manual translated from Chinese that is somewhere between helpful and poetry. Strong grip voltage. Weak grip voltage. Winning voltage. Strength maintenance time. Award probability, in how many goes you want to give a prize.
That last group is the quiet admission in every claw machine: the claw is not always trying. There is a setting for how hard it grips, another for how hard it grips once it has lifted, and a counter deciding which go is allowed to be a winner.
The wiring diagram is what made the remote control possible. Every button on the front of the cabinet is just a line on a harness: start, left, right, upper, lower, and the coin lines. If you can close those contacts yourself, you can play the machine without touching it, and the board carries on believing a person is standing there.
The documentation I had to work from, for anyone who ends up with the same board.
Playing it from somewhere else
The goal was always that someone who is not in the room can play. Commands travel over the internet to the machine, the machine closes the right contacts, and a camera inside the cabinet sends back the view so you can line the claw up against what is actually in there rather than what you remember.
This is the part of building things I enjoy most. Software on its own is pixels moving around. Software attached to a gantry, a claw, a prize chute and a coin line is a thing you can stand in front of and watch happen.
More to come
There is a lot more to write about here, and a lot of video of it working, failing, and dropping things from a great height. I will put that up as I get it edited. For now, it exists, it runs, and you can play it from the other side of the country.