Claw Machine
This claw machine was a project for my daughter’s third birthday. I programmed, designed, and built everything from scratch.
Modes
Standard Mode:
In standard mode the player chooses the X/Y position with the joystick and then presses the blue button to freeze the X/Y position and posit the claw for an attempt at a stuffed animal. The claw opens and lowers until the spring force on the tensioner bar overcomes the limit switch. The claw then closes, raises and moves to the prize chute.
Free Play (full control mode):
In free play the player is given full control over all controls with no time limit. The goal for creating this mode would allow the player to be able to pick up and stack objects or create their own objectives. For the toddler this was created for I imagined stacking blocks to create towers.
The potentiometer allows direct and fine control of the servo controlled claw.
Features
Controls:
I designed/printed a height adjustable control box.
Joy Stick: X/Y positioning
Blue Buttons (Standard Mode): Either blue button will initiate the claw to make an attempt at a prize.
Blue Buttons (Free Play only): The top button will raise the claw, the bottom button will lower it.
H knob (Free Play only): Potentiometer to control the opening and closing of the claw servo motor.
Coin Button: Start Standard Mode
Single Player Button: Start Free Play Mode
Tension Detection:
While lowered the tension detection is able to tell when the claw has stopped lowering in order to prevent the reel from tangling. The rope loops around a tensioner bar before continuing down to the claw. This tensioner bar needs tension in order to overcome the spring shown below. When the claw looses tension the limit switch against the bar is released.
LED Light Strips (WS2812B):
Outside top perimeter: Implemented as a rainbow light show to attract players.
Play area ceiling: Currently white to better light up the stuffed animals.
Planned sign backlighting: I have already created a sign using acrylic glass and vinyl cut to allow illumination. I have not yet created housing for an LED strip or programming for the
Custom Python Coding
I had to learn python in order to create the code for this project. It was a lot of fun to play around with and get working as intended. Most was copy and pasted from examples but getting them all functioning together and the overall game modes were custom made.
I have rising edge detection for the limit switches so that at any point in the code I can stop the motors to prevent damage.
Open Claw Machine Project © 2025 by Gavin Snyder is licensed under CC BY-NC-SA 4.0
