How I Designed a 3D Printed Windup Car Using Autodesk Fusion 360.

cults3d

https://www.youtube.com/watch?v=H3Qq4KZpJF8 I've spent years designing, 3D printing, assembling, testing, and publishing numerous PLA spring motor floating pinion cars and demonstrators, so why would I design, print, assemble, test, and publish yet another one? The answer is simple: innovation. In this video, I'll be walking you through the design of a new PLA spring motor floating pinion car that pushes the boundaries of what's possible with 3D printing. From its sleek chassis to its high-performance axles and wheels, every component has been carefully designed to work together in harmony. First up is the chassis, which consists of two frames: "Frame, Right.stl" and "Frame, Left.stl". To gain additional ground clearance, I've modified the gear train layout and used the PLA spring motor and gear train components to assist with laying out the right frame. With the right frame complete, the left frame is created by projecting the right frame profile and modifying the various socket and crossmember profiles to allow mating of the two frame sides. Next, we have the axles and wheels. There are two unique axles: "Axle, Gear, Floating.stl" and "Axle.stl", and one unique "Wheel.stl". After centering the car assembly, the rear axle is designed and then copied and pasted to create the front axle. Next, the floating pinion axle is designed and positioned. Now that we have all the components, let's talk about the math behind this design. The total gear ratio from the PLA spring motor to the drive axle is 1:9 (drive to driven), using two gear stages of 1:3 each. This results in a loss of torque but an increase in rotational rate from the PLA spring motor to the drive axle. With a wheel diameter of 47.5mm, the distance the car will travel under spring power is approximately (assuming zero traction and friction losses): (pi * wheel diameter) * 1.25 * 9 = 1678.788574262046mm = 5.5 feet. To test the math, I fully wound the PLA spring motor, held the car firmly on a smooth surface along side an extended tape measure, then moved the car forward by hand noting that the floating pinion gear indeed disengaged the PLA spring motor from the drive axle at exactly 5'6" (ok, math isn't that bad after all). Finally, remember after the PLA spring motor energy is depleted, the floating pinion disengages the PLA spring motor from the drive axle allowing the car to coast. During testing, my cars coasted an additional 15 feet and more after the PLA spring motor energy was depleted. This design represents a major breakthrough in PLA spring motor technology and I'm excited to share it with you all. So sit back, relax, and enjoy the ride as we take a closer look at this innovative design.