Imagine creating cutting-edge robotics on a shoestring budget! At MIT, when the word 'low-cost' is used, it might not mean what you think. Enter Caden Kraft, a resourceful innovator who faced high prices while trying to equip a SCARA arm with the ideal actuators, initially eyeing the pricey $300 Mini Cheetah. But instead of breaking the bank, Caden took matters into his own hands.

Revolutionizing Design with DIY Ingenuity

Caden crafted a quasi-direct-drive actuator that pairs a brushless DC motor with an innovative integrated gearbox. His goal? To keep everything lightweight and efficient, all while ensuring that parts could be 3D printed. Tossing out the traditional backing iron for magnets, he ingeniously arranged them into a Halbach array—simulations showed it performed nearly as well as more expensive setups.

Unlocking Torque: The Secret of Cycloidal Gear Profiles

To supercharge torque, Caden integrated a planetary gearbox featuring cycloidal gear profiles, which not only minimized backlash but also cut down stress on the teeth—perfect for 3D printing! He even enhanced an existing Python program to generate custom gearbox designs, making it easier for enthusiasts to replicate his work.

Testing the Limits: Thrilling Results!

Once assembled, Caden tested the actuator by attaching it to an arm and applying force. Although it initially drew too much current for his power supply, a switch to an EV battery module unleashed a staggering 29.4 Nm of torque—almost triple his original target! He pushed it to draw 50 A, stopping only to avoid exceeding the actuator's limits. And here’s the kicker: he accomplished all this for less than $80!

A Gamechanger in Robotics!

If you’re intrigued by this marvel of budget engineering, you might recall our previous feature on the Mini Cheetah and how similar designs are revolutionizing quadrupedal robots. Caden’s work shows how with creativity and determination, the world of robotics is accessible to all.

Kudos to Delilah for the insightful tip!