Wednesday, February 15, 2017

FIRST Robotics 2017 - Build Season Week Five / 2

Misgivings.

With our complicated "Build Two" strategy the time frame for what has to happen and when is important.   You can only fiddle around with peripheral stuff for so long.  When the count down gets short you have to tackle the major issues.

We have to have to know what kind of winch we will use to actually finish the frame.  The robot is effectively built around it.  The disappointing test run of what was supposed to be an infallible system set us back.  Some engineering tweaks have ensued but a final successful test has not been done yet.

But things had to get done.

So.  Thursday: 

We have decided to take on Faith that the winch will work in its current form.   I put a couple of kids to work building frame elements to accommodate it.

A light turnout for work crew tonight.  Especially on the ball shooter.  One guy intensely thinking.  Whiffle balls litter the floor.  Periodically he makes an adjustment to the mechanism and fires off a few more.  His hat matches the whiffle balls.



Steady progress.  This is the practice machine and so is still a bit rough.  But at the end of the night I stare at the robot.  And courtesy of its camera, the robot stares back.




Friday Another night of a short work crew.  We share a large percentage of the team with various music programs so when there is a big Band/Choir extravaganza the robot comes in second.  We continue to struggle a bit.



This little widget is called a Lovejoy coupler.  It was part of our solution to the winch problem and allows just enough play in the system to overcome any minor misalignment.  The problem is that it added two inches of length and now the winch motor bumps up against something that can't be moved.  Much dismay and kludgy theories but so far no solution.  I am feeling neither The Love nor The Joy tonight.

Saturday  All hands on deck.  We have two coaches who are there all the time.  And four "part timers" who help as work permits.  Three of the four turned up on Saturday and Stuff Got Done.  By the kids it should be noted, but a degree of supervison on light to moderate mechanical matters helps a lot.

Mounting the alarming winch motor on the Competition machine.  You really try to avoid drilling and grinding on a machine with active electronics because getting shavings in the wrong places makes for an expensive failure.  But on occasion there is no choice. 



The cure for shavings.  A careful vacuuming up, sometimes followed by a damp paper towel.  


Build season is an intense experience and Week Five is the worst.  Fatigue has set in but the final burst of energy that comes from panic is still a few days away.  We made it through.  It helps to remember that we had goals at the beginning of the campaign.  By the end of Week Five we wanted to have a machine that reliable handled the plastic gears and that could climb the needed distance in under fifteen seconds.

And have a practice machine that was mechanically identical if not as pretty.

End of Week Five.  It runs.  It picks up and drops off gears.  It climbs in between 6 and 7 seconds.

No time to rest but with a strong effort today we are back on schedule.



Oh, and the pesky ball shooter project.  I had to put it "on hold" for Saturday morning.  We needed all the hands working on the competition robot and the darn whiffle balls are a distraction.  But by afternoon the lads were back to work on it.


video

2 comments:

jon spencer said...

You can shorten a Love Joy a little by grinding the wings down and then sanding the spider a little thinner. You do lose some of its strength, don't know how much torque and misalignment you have. Those couplings are pretty strong though.

Tacitus2 said...

Well, it works fine with the motor in a vertical configuration. Ran into a new headache tonight....glad we have a few days to make some adjustments. High schoolers. Its like herding cats without catnip, a broom or a laser pointer.

T