Raiderbot X Meeting 3, 41 Days to Robot Ship

Meeting time: 15:00 to 19:00.

We will have budget discussions every Tuesday after meeting.

FIRST Choice parts ordered, including the FTC Mini Kit for the minibot.

Talked more about end effectors, spent 30 minutes prototyping. Kushal and Damian made a pretty sweet prototype of a four-bar linkage arm.

I messed up here again and completely forgot that we’d planned to finish design decisions by end of the day today. Didn’t happen. Where’s my todo list? I need to make a Gantt chart soon.


Raiderbot X Meeting 2, 42 Days to Robot Ship

Meeting time: 15:00 to 19:00.

Continued talk about end effector design. We built prototypes and tested them in the shop, but just as Will was showing the old triangular scissor lift and I was wondering why there were suddenly so few people, my sister ran in and told me Mr. C (my youth symphony director) was looking for me.

Okay, major slip-up on my part.

Panicked, I promptly ran out of the shop, simultaneously realizing that I had left my violin in my locker and that that was why I felt something was awry as I walked away from my locker earlier today. In the orchestra room, I grabbed and opened a random violin case off the shelves only to discover a long-neglected violin with all four pegs loose and strings going everywhere (and collapsed bridge, needless to say). Fortunately, the next violin was in decent condition, albeit I had to play without a shoulder rest. It wasn’t my first time. It probably won’t be my last.

Halfway through rehearsal, I realized there was a (robotics) team budget meeting at 7:00 I had assured Will I would be at.

I hope never to be so stupid again.

Raiderbot X Meeting 1, 43 Days to Robot Ship

Meeting time: 15:00 to 21:00.

Printed 73-page game manual. Everyone should read the rules!

Reconsidered different drive designs (swerve, mecanum, simple, treads, omni, casters) and decided to go with swerve over mecanum in a 10-7 vote. Note the total number of votes. We have 46 people on our roster. Granted, the five PR people and some others who were working on the battery cart were not counted in that total, but I should’ve called for mandatory strongly recommended attendance for these first few days.

Also started talk about end effector design and minibot ideas. We need to nag people to come to meetings.

One thing I’ve now noticed is that if I have an idea and put off implementing it, I eventually argue myself into thinking it’s a stupid idea or other things turn up that distract me. The greater the time passed, the less likely I am to actually do it. Obviously, if I neglect to write such ideas down, I simply forget them.

I need to execute.

Raiderbot X Meeting 0, 45 Days to Robot Ship

Meeting time: 9:00 to 14:00.

Read the rules.

We hosted a team from Canby, OR per their request for a place to brainstorm after the Kickoff. Our classroom was packed.

Will wanted to set up a mock field using tape and play the game using human robots, but as LogoMotion is a very three-dimensional game, that plan was scrapped.

We identified the three parts of our robot: the drivetrain, the end effector, and the minibot. The chassis will simply be anything to hold the system together. The team was split into three groups to come up with ideas. At the end of the day, these were presented to the team.

Here are some pictures:

Design process

Design process

Minibot ideas

Minibot ideas

Drivetrain ideas

Drivetrain ideas

UPDATE 1/15: In retrospect, playing the game would have been very useful. At least, I can see now what Will was thinking by suggesting we play the game before doing anything. Before designing, we needed to identify the functions of our robot, and to do that, we needed to decide on a strategy. Strategy is a lot easier to explore when we can watch (or play) the game.

FIRST Robotics 2011: LogoMotion

FIRST Robotics 20th season finally started! Here comes another six weeks of the hardest fun in the world.

This is Team 955’s 10th anniversary as well. Raiderbot X!

LogoMotion: game video here. It looks awesome.

Lots of people at Kickoff at LaSells Stewart Center. I am surprised at how many rookie teams there are this year compared to the number of veteran teams (maybe my memory is just bad). There are now more than 2000 teams in total.

First thoughts:

  • Rack ‘n Roll!
  • Minibot is awesome!
  • Lots of sensors and camera tracking; this should be fun.
  • Need reliable autonomous to use that ubertube.
  • Center field is going to be chaotic.
  • Can we just shoot the minibot to the top using a spring?

Tricopter: Bill of Materials

I have posted the running bill of materials for the tricopter on my github account here.

Combined with the cost of new tools and shipping (over $600!), this is the most expensive activity I have funded on my own. I feel good that I am using my internship stipend to do this, but this had better work.

Project: Tricopter

It was the AR Parrot drone that first piqued my interest in quadrotors early last year. I then started seeing autonomous quadrotors being made by universities and decided to make my own.

Soon afterward, I found videos of a multirotor variant people had dubbed the “tricopter” due to its use of only three rotors arranged in a triangular formation. Unlike a quadrotor, the net torque generated by the three rotors is not zero, so the tail rotor is mounted on a servo-actuated axle to compensate for this torque and provide yaw control.

Besides the fact that having three rotors and arms is cheaper than having four (a servo costs about $10), a tricopter just looks cooler than a quadrotor. That, and all the universities have quadrotors already. I want something different.

I found a gigantic tricopter thread on RCGroups that is a good source of other people’s tricopter builds, even though they all use simple radio equipment with no room for programming. The thread is actually useless to me past the first 100 posts or so. I just like watching their videos and wonder why they don’t fly any higher than a few hundred feet.

The material cost for the tricopter itself ends up being about $400. For this prototype, anyway. I will rebuild it with much nicer materials (aluminum? carbon fiber?) once I get past the testing/breaking stage.