The Enchanted Claw Machine

Inspiration

We all loved playing (and losing) the claw games at amusement parks and carnivals. We wanted to make a minute version of this popular game, so more people can fairly enjoy the rush of winning a prize from the claw game. We also wanted to design something fun that people at the Hive could enjoy during their study breaks.

What it does

It is a miniature claw machine that has three axis motion. Two axes are handled using a gear and pinion mechanism to allow our magnetic claw to hover anywhere over the game field. The third axis is handled by a spool of thread that winds and unwinds to lower and raise a magnet that will pick up small magnetic animal tokens as prizes. All motion is controlled by pushbuttons to move the magnet across the field and raise and lower it.

How we built it

We built our Enchanted Claw Machine primarily by laser printing wood for the structure as well as the gears and pinions. The two-axis movement and the dropping movement are controlled by three motors (two stepper motors and one DC motors. These motors are all controlled by motor drivers and a Arduino Mega. The two-axis movement is generated through a gear and pinion to convert rotational movement into linear movement. The claw movement is actually a magnet. Players can use the front panel to control the game.

Gear and pinion. Motor driver.

Challenges we ran into

The biggest issue we ran into was power draw. The stepper motors draw a lot more current that it seems to require. We ended up overcoming this issue by using two DC/AC wall adapters (12 V, 2A). This is a lot of power for a 3 motor circuit with a relatively small amount of torque.

It was also difficult to overcome the instability of the gear and pinion connection.

Power. Stability of gear and pinion.

Accomplishments that we're proud of

We are proud that we got the 2 axis motion to work and that the structure came together and actually resembles a cute, enchanted claw machine!

Getting 2 axis motion to work. A final product resembling the initial sketch.

What we learned

We learned how important it is to focus on power budget and current draw. We learned that occasionally it is important to simplify a design rather that over engineering. Another key thing we learned is to always have a plan B. From a technical standpoint, we learned more about laser printing specifically mechanical parts.

What's next for The Enchanted Claw Machine

More prizes! We would love to re-vamp the look of the enchanted claw adding some final touches (acrylic, more prizes, more refined look). More importantly, we want to improve the gear and pinion system, work on over current draw, and fix the up/down motion for picking up prizes.

Finishing up some of the front end aesthetics. Add more prizes. Fix motor.

Built With

• c++