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VEX 7009X

I programmed for 7009X, Xcceleration, in V5RC. Two high school seasons, the last one Push Back with a robot called Quicksilver.

The record

  • World Championship Division finals, Think award
  • US Open 2nd place
  • Georgia States 2nd, two seasons running
  • Tucker Excellence, Tournament Champion, Skills Champion
  • East Forsyth Tournament Champion, Skills Champion
  • Carolina Countdown Innovate submission

Forty-four awards in total across middle and high school. Sixteen of those came in the two high school seasons, which is the stretch this page is about.

28 middle school 16 high school, two seasons
Forty-four in total. The right-hand block is the part with my name on the programming pages.

Skills was the thing we got wrong

The season before, we did not run robot skills at Worlds at all. The reason written down in the notebook is blunt: we did not think we had a real shot at Excellence, so we did not bother. The same page calls it a missed opportunity. nobody else is on the field

It is the honest kind of mistake, because skills is the half of the competition entirely inside your own control. There is no alliance partner, no matchup, no elimination bracket. It is your robot, your autonomous, and sixty seconds.

So the next season we took it seriously, and the results table changed shape. Skills Champion at East Forsyth on the twentieth of October, two of the six awards at the event and a State qualification out of it. Six days later at Tucker, three of six: Excellence, Tournament Champion, and Skills Champion again.

Two local events, five awards, and both of the things we said in May we would fix.

The line

The part of Quicksilver I would point a judge at sits on the underside.

There is a line across the middle of the field that a robot is not supposed to cross during autonomous, and the blocks worth taking sit right up against the far side of it. You can drive to it by distance, some number of inches and then a turn, and that works until the field is set a quarter inch off, or the wheels slip on a scuff, or the battery is lower than it was the day you tuned it.

distance alone a good day and a bad one look the same until they don't with the line sensor stops on the line, then swings no number to get wrong
The blocks sit past the line. The robot has to reach it and not cross it.

So we put a line sensor on the bottom of the robot. It drives forward until the sensor sees the line, stops there, and swings a hundred and eighty degrees to intake. It is not aiming at a distance any more, it is aiming at the line.

That was our Innovate Award submission at the Carolina Countdown signature event, and the sentence we wrote on the form is the one I still believe: crossing the line leaves a lot of room for error even after extensive tuning, and a sensor takes the tuning out of it. The mechanical half mattered too. A sensor on the underside of a robot in a contact sport does not last, so it sits behind the drivetrain sleds, which were already there and already taking the hits. By December there were five sensors on the robot, and the cheap one on the bottom is the one we put in front of judges.

Two days out

In December we moved the whole codebase onto LemLib, and then a competition was two days away and we wanted autonomous routes for both sides of the field.

The note in the notebook reads: since we only have 2 days till our competition, we will reuse our route from our old robot and only make a left side. This will let us tune what we have instead of having multiple untuned autons.

One tuned routine beats two untuned ones every time. Knowing which of those you are two days away from is the difference between a result and an excuse.

The notebook

Most of a season lives in that document. Dated entry by entry, indexed against each stage of the engineering design process, past two hundred and forty pages in the second book alone. The Think award goes to reasoning rather than results, and the notebook is the only way reasoning reaches someone who was not in the room.

The entry I would keep is not an award. It is the one from May that admitted we skipped skills because we assumed we would lose, written months before the table above existed.