Dual Mode Spring Motor Rolling Chassis

cults3d

Despite having identical gear ratios to my previous "rolling chassis" designs ("Spring Motor Rolling Chassis Version 2" here: http://www.thingiverse.com/thing:2011107, and "PLA Spring Motor, Rolling Chassis" here: http://www.thingiverse.com/thing:430050), the Dual Mode Spring Motor Rolling Chassis outdistances both thanks to its dual mode operation. The first mode is identical to my previous two rolling chassis designs, using a PLA spring motor to power the chassis. The second mode is new, "true coast". Unlike the previous two designs which depended on a weak pawl to release from the pawl gear for coasting, (which, due to friction, limited the distance these vehicles would coast), true coast utilizes a floating pinion gear (I published a floating pinion demonstrator here: http://www.thingiverse.com/thing:2025927). Under spring motor power, the rear axle is connected to the spring motor via the floating pinion gear and the torque from the spring motor. When the spring motor energy is depleted, the floating pinion disconnects from the rear axle via the rear axle gear pushing the pinion back to its parked position, allowing the rear axle to free spin and the chassis to truly coast. Video of my prototype can be seen here: https://www.youtube.com/watch?v=-DkAy472jlo. A comparison between the "Spring Motor Rolling Chassis Version 2" and the "Dual Mode Spring Motor Rolling Chassis" can also be viewed here: https://www.youtube.com/watch?v=PjmT369N0wM. The two photos are first, my actual prototype, and second, the output of Fusion 360 (without the o-rings). To complete this project, you will need to purchase four AS #213 o-rings (1 3/16" O.D., 15/16" I.D., 1/8" diameter) and eight AS #223 o-rings (1 7/8" O.D., 1 5/8" I.D., 1/8" diameter), which are available online, and at plumbing supply / box stores. This design was created using Fusion 360, sliced with Cura 2.3.1, and printed in PLA on an Ultimaker 2+ Extended and an Ultimaker 3 Extended.