Day 23 – Wheel Selection (1/26/2020)

Authors: Ritik Mishra, Andrew Georgioff

Wheel of Fortune

The completed Control Panel/Wheel of Fortune was brought in today. This allowed us to clearly see how much space you had when driving underneath it. In the future, this will allow us to test mechanisms and code for completing the control panel objectives.


The climber was changed to make it lighter by changing the bars from 2×2 to 2×1, and more realistic by adding a CIM a gearbox to it. After this it was tested and it still worked well. 

Looks like we’re not winning the safety award anytime soon


Yesterday, we had noticed a clicking/ratcheting sound coming from the drivetrain that occurred whenever we rapidly braked the drivetrain. As it turns out, one of the gearboxes was improperly assembled. Based on the pinion size, there are two positions for the motors: an inner position, and an outer position. Since we are using 11 tooth pinions, the motors are supposed to be on the inner position, but one of them was in the outer position instead. After fixing the problem, the drivebase drove quite smoothly. 


The testing of wheels from yesterday was continued today. After extensive testing at a variety of distances, we finally decided to use colsons over blue compliance wheels because the colsons are more durable, so they would not need to be replaced as often. Otherwise, were not able to observe a meaningful difference in accuracy between the two wheels. 

Above: Testing a blue compliance wheel on the flywheel. Also note that on our power port there is a side beam which does not exist in the actual field so some shots which bounce out would not in a match. 

Above: Testing a single colson on the flywheel with the power port 35 feet away from the flywheel. 

Above: Testing a single colson on the flywheel with the power port 10 feet away from the shooter, making it much easier than the 35-foot shot. This is the distance we will likely shoot at during the autonomous period. 

Above: Testing a single colson on the flywheel with the power port 20 feet away. This is the distance we will likely be shooting at when shooting from the trench

Chain in Tube Proof of Concept

We investigated the ease of assembly of a chain-in-tube setup. We used two 18 tooth #25 pitch sprockets, since we had some on hand, and because even our 12 tooth #35 pitch chain sprockets would not fit inside our 2x1x1/8” box tubing with chain wrapped around it. 

As it turns out, it was very easy to assemble, as long as the loop of chain was pre-prepared. Once we had drilled all the holes and had some practice, 1 person was able to assemble it in about 10 seconds.

We also saw that there was little wear created by the chain on the tube. One drawback of a chain-in-tube setup, however, is that there cannot be any protrusions into the tube, such as rivets or bolts. 

Quote of the Day: “If it’s not in high gear I’m scared – Ryan Mikol, Strategy and Scouting Lead