FTC Team Arrowhead – Build Blog Week Six

Brief Summary

This week was very productive because of the multiple unofficial meetings and the extreme changes to the design that were fostered into the making of this robot.

October 28, 2019 (unofficial meeting)


Expansion Hubs

Attempting to fit the expansion hubs, the members spent most of their time with building drilling holes into a rectangular piece of polycarbonate which would attach to the backend of the robot. Afterwards, they realized that the easiest way to attach the expansion hubs to the piece was to use double sided tape.

Maker space left at 6:30 PM


October 29, 2019 


Compliant wheels

The designs for the compliant wheel arms were initiated. The members planned on jerking the robot forward so that the arms could fall forward extending the length. The length robot needed to be, at most, 18 inches, but the length could change during the competition, hence jerking the robot forward to extend the length. The engineers decided on using hinges, and the hinges were cut to be flush to the edges of the chassis.

Expansion hubs – placement of the battery

The battery placement was crucial, and the members now were on to attaching a stationary cradle like structure to keep the battery from rolling around. However, since this structure would not provide to keep the battery from falling out when moving, another tactic was added to the design. This was to add surgical tubing which would ‘tie’ down the battery to the cradle structure. The members considered this design as the battery can be taken out when it needs to be charged.


The programmers of team Arrowhead watched video on PID — proportional integral derivative. PID, which helps find the exact location of motor movement things like gravity, uses past info and future predictions updates real time helps with elevator. They said that they were learning things that they had not known before.

Maker Space left at 6:30 PM


October 30, 2019 (unofficial meeting)


Expansion hub

The expansion hubs were already attached with double sided tape, but the battery still needed to be attached. Holes were drilled to the polycarbonate for the battery. However, this took a very long time due to the elevator being installed at the same time, and the battery holder needed to be attached to the chassis base.


The elevator was built and attached. 

Attaching battery + testing out elevator

Maker Space left at 6:38 PM


October 31, 2019 


Suction Cup

A suction cup was made using hot glue. However, due to its inflexibility, the suction was not able to grab onto the flat surface of the skystone.

Another suction cup was made, this time using surgical tubing. After attaching it to the vacuum with the use of a tube, we discovered that the new design worked.


PID – learning from lectures

The programming lead, Ishan, gave a very compelling lecture about proportional integral derivatives. They discussed on how precision cannot simply be achieved with precise numbers.

Earning points

The programmers also discussed the most efficient and effective ways to accumulate points. 

The programming squad
“How to earn points” board

Maker Space left at 7:00 PM


November 1, 2019 (unofficial meeting)


Expansion Hubs

It was discovered that the expansion hubs needed to be separated because the motor from the elevator was blocking the placement of the polycarbonate and expansion hub concoction. The engineers were able to attach them separately using bolts and zip ties which work surprisingly well for this purpose.

Robot as of Friday 11/1/19


They discussed the best way to confront conflicts and earn points as the robot was still being built, and both the expansion hubs were in use.

Ending the Night

The week had overall been very productive, but by the end of the meeting, everyone was extremely hungry and tired. Dinner was eaten at the end of the meeting.

Dinner featuring Domino’s 

Maker Space left at 8:10 PM