Monday, February 20, 2017

FIRST Robotics 2017 Build Season Week 6 - Wrapping Up.

Final week of robot building. We do have Monday and Tuesday of the following week but that's not a good time to be finding and solving major problems.

In the week concluded we did find and solve some minor ones.

A careful read of the rules suggested that depending on the mood of the judges our robot's frame might be a quarter inch too long.  A hat tip to the build team who were able to make the modification in under an hour, and actually made the frame cleaner and stronger in the process.

It is very helpful to occasionally test drive the near finished product.  We had done careful measuring to set up our gear pick up and delivery systems at optimal heights.  But in testing an odd thing happened.  When our winch mechanism was not mounted the gears did not slide into their designated carrier easily.  And when it was, they did not come out cleanly. Hmmm.  Much pondering at, as is universal, the end of a work session.  There even seemed to be some contribution from the slightly uneven floor of our century old build HQ.

But the real issue was the weight of the winch.  When it is off the robot is "nose heavy" and tips forward.  When on, "tail heavy" and tipping up a critical quarter inch.  Sigh.  Still time to do something.  Various somethings were debated.  We wanted a solution that would accommodate the wear and tear that is to be expected on the arena elements in a rough and tumble event. Springs don't always stay perfect and the retaining spike could get beaten up.

Solution: a tiny rectangle of polycarbonate attached to a little servo.  

When the gear is released this should push its lower edge forward and make a clean drop.  I met with some resistance on this addition.  The originator of our simplistic gear release wanted to assume that the springs at the event would be forgiving.  But as I explained, the robot is only as strong as its weakest part, and the difference between victory and defeat could be a single gear handled cleanly or dropped.  As the pressure has stepped up in the last week or two I have become a continuous font of platitudes.

By Friday we were done enough to:

Run a mock inspection of the robot.

Make a very nice set of bumpers.

Do drive practice on a section of carpet we rolled out to better simulate the actual field surface. 

Put on signage for our much appreciated sponsors.

And Saturday was mostly frosting.   Oh, we had a minor issue with our rope grabber missing too often.  But it turns out that the red duct tape we had applied for visibility and general safety had frayed and balled up from multiple use.  Replacing it, probably often, with slick, thinner electrical tape solved the problem.  Looks pretty safe, no?

We finally have the ball shooter mounted and are trying out various feed systems.  We should have been at this point two weeks ago.  As our build space did not have high enough ceilings we took the robot down to the loading dock....and set as our target a trash can balanced on a forklift!  I really think that for a FIRST robotics team we are a bit weird.

We probably only have an hour's worth of real work to do before we bag it.  So even though the kids have Monday off of school we will forgo extended practice hours.  Our Pit Crew motto applies from this point forward.  "The Robot is Always Ready".

At least that is our hope.

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