The Ring Stamper is a device for reworking incorrectly-formed outer rings. Outer rings are stamped-metal parts responsible for the ground connection shared between Cubelets. A large order of outer rings were manufactured in a way that led to unreliable ground connections, so the Ring Stamper was designed and built to correct the rings.
Rings are inserted into the top of the device, where they slide down and are held in position by two metal pins. The main pressing action of the device is driven by a large pneumatic cylinder, which drives an appropriately formed pressing face into the ring. Once the ring is stamped, the holding pins are retracted by a smaller pneumatic cylinder, allowing the re-worked ring to drop out of the bottom of the device.