According to the HackADay crew, the build kicked off with an old 10″ Ashcroft pressure gauge obtained from eBay. After dissecting the gauge, Murphy’s_Lawyer began constructing a method of generating motion without the need for actual steam.
The solution? Mounting a continuous rotation servo between the Bourdon tube and the case. However, the servo lacked the strength to flex the tube on its own – so a simple brass lever was ultimately designed to assist.
“The electronics consist of an Arduino Uno (ATmega328) and an accompanying homemade PCB. The code for the Uno generates random motion for twirling the servo, [while] three LEDs built into the face reflect values generated for speed, pause and run time,” explained HackADay’s John Marsh.
“The final upgrade came in the form of a new dial face, which provides some updated text as well as a cutout square that lets you see the previously obscured gears in action.”
“Push a button and the die will display a random number from 1 to 6 just like a dice! [The kits are] great for board games. [Plus], you get a free CR2032 battery with each kit!” applemount wrote in a description posted on eBay.
“[The kit] uses advanced on-board entropy collection to generate real random numbers. Soldering is required, [although] each part is clearly labeled on the printed circuit board for easy assembly.”