Servos and Gears

Week of January 17th, 2022

The servo mounts finished printing! The hole for the servo seemed too tight of a fit, however. It seems like the extra space needed for the servo cables to come out the side of the hole was not accounted for, so modifications had to be made. The team ended up drilling one end of the hole for this additional space, and the servo fitted nicely!

Initially, the gears were planned to be 3D-printed, but the team figured that laser cutting plywood to make them would be way quicker. However, to achieve the desired gear thickness, several copies of each gear were made and glued on top of each other.

The gears mated perfectly on their own, but it was realized that they were not coplanar when attached to the servo mounts. It turns out that the bigger gears were a bit too heavy for the servos to handle, which caused them to tilt slightly as they were spinning. Although the tilt angle does not seem too big, it caused the servo to stall sometimes. The team then decided to cut holes through the gears in hopes of decreasing their weights, and in turn, the tilt.

With the new gears with holes cut out, the tilt angle was decreased, and the stalling of the servo did occur less, but still happened nevertheless. Since having the gear system get stuck is very difficult to fix once the whole device is assembled, the team looked into stronger servos that would be able to overcome the tilt without stalling.

The new servos came, and it works better than expected! In addition to being able to handle misalignment of the gears (i.e. tilt) better than the old servos, it turns out that they also did a better job at supporting the weight of the gears, having almost no tilt between the planes of the gears. The only way to know for sure now if they will work together with the whole suction arm mechanism is to place them on the mounts, but unfortunately the mounts had to be redesigned and reprinted to accommodate for the larger size of the servos.