FIRST Robotics 2023 Report - Week Three

Ideally you work out your robot design in weeks one and two (while staying busy with construction of field elements and such).  Then in weeks three and four you build the machine.  Weeks five and six are for software tweaking and the very important drive practice.

We had several good sessions in Week Two, but did not have final details hammered down.  So Week three was "make what you can" and design as you go.  

On Monday we had to make a call on whether the final machine would be 26 or 27 inches wide.  Instead of calculating center of gravity and figuring things out we took our 27 wide test bed, slapped some heavy two by fours to it and drove around with the throttle dialed up to something near full power.

It seemed to handle the test well, and at this point without the extra weight a steel base plate will add.  So the competition frame went to Robot Surgery.

Although many aspects of the robot are clearly on schedule, and for most issues solutions can be seen, I had a nagging worry as Week Three went along.  We still did not have the simple looking - but actually devious - "numbers".  Arm lengths, pivot point, attachment and angle of the actuator that moved the system.  It looked like it would work on paper.  Even in CAD.  But our trusty wooden test bed said otherwise.  Linear actuators are inherently slow but powerful.  But in our application there is an issue.  Put the mounting point close enough to the pivot to get the necessary speed and you don't have quite enough power to move the arm.  Put it farther away and you have the power but glacial movement that will not serve in competition.  So we headed into the crucial Saturday session needing one of three or four in hand alternatives to work.  And right quick.

A low speed, high torque winch working against a gas shock did the job nicely.  A few details on how to brake but not break the gearbox will be handed over to software.

It's good to see the ideal level of activity.....as many students as can get useful hands on the robot under construction.  The only adult in up close is mostly there to keep heads out of "the bonk zone" of the arm.  

Many things going on in other parts of the workshop.  Someone suggested that our test bed doing well on the field elements was due to it being very light.  OK....pile on two extra batteries and a huge brick that was around for some reason.  It just made the traction better.  Note....low speed testing only, this was held together with tape and C clamps.

Software is still doing some kind of Wizard Math.  

This time of year the end of session gets a bit cluttered.  It is - within safety parameters anyway - a marker of progress.  Here's our supply closet.  Note the control board with big colorful buttons.  It looks as if we'll have both a driver and a mechanism operator, the latter having preset buttons for the different coordinates in space for picking up and dropping off.

The wooden bumpers have to be a perfect fit to the outside of the robot frame.  Done properly they supply some extra strength and more importantly keep the robot from damaging things.  A pesky job.  Throwing away last year's edition once they'd been taken apart was a pleasure.

I think the Brick Test used up all our red tape.  So the small team working on refining the grabber arm did not have any to mark their box of Do Not Touch hardware.  They did get the skull and crossbones right though.

A good session.  A good team.  Eventually maybe a good robot.  There are still potential issues but the further along you get the more you learn.  The kid's brainstorming on the tasks for the week ahead and for alternate ways to get things done "IF" something fails is good stuff.

Learning to do this, especially with a bit of pressure from the clock....and lets just be honest, from me, is more important than anything they build out of metal.