2015 2nd Choice Robot
 

One thing I love about FIRST this time of year is I get to look back at what I originally though was a viable idea and then realize how dumb I was.
What did you guys think was viable this year but you didn't use for various reasons?
I think my favorite idea this year was two minibots tethered to a robot on one end of the scoring platform. Totes would be brought to the robot that creates stacks and the stacks would then be pushed onto the scoring platform.
What were your guys initial thoughts that you didn't go with for various reasons?

Re: 2015 2nd Choice Robot
 

The programming department suggested Mecanum Wheels as our robot is heavily dependent on being aligned with the tote chute. Of course, being the programming department, our idea was quickly discarded by design with the reason "that's too hard to build". The driver now has to struggle to back out and drive in repeatedly in order to get in the right position.

The idea of being able to stack a bin was also suggested. It too was shut down because they wanted to use the door latches instead of building our own latches, so our stacker is too narrow to accommodate for a bin.

Re: 2015 2nd Choice Robot
 

Our team was going to have a "flipper" on the back to flip over the upside down totes to allow our robot to lift it. We were border lining the weight limit so we had to discard the idea.

Re: 2015 2nd Choice Robot
 

Our team was convinced we were going to nest the totes inside each other before we found out they were ziptied shut. :(

Re: 2015 2nd Choice Robot
 

C-shaped chassis. I was all for it, I said "all the good teams are going to be doing it! We'll tip otherwise!"
Nixed and problems ensued with the weight being too far forward. :P
I was on the fence about tipping cans upright, but after seeing the real things I am whacking myself for not devoting mroe time to the issue.

Re: 2015 2nd Choice Robot
 

Same here. I promoted it, but we decided against it because we believed that we couldn't make it strong enough without a front support.

Re: 2015 2nd Choice Robot
 

We thought one of those sideways sliding drivetrains using omni wheels would be really cool for this year, since there's no defense, but when we looked at space allocation in the middle of the robot, we decided against it.

Re: 2015 2nd Choice Robot
 

We had two team members heavily advocating for a robotics arm. A really big three axis arm. Just park in the middle of the field, and be able to reach anywhere. Then we did some torque calculations and figured out it would require ~45 ft-lbs of torque just to keep from collapsing, let alone having a tote at the end. It was nixed.

Re: 2015 2nd Choice Robot
 

Our second choice was nicknamed the 'Captain Hook Combo' during our brainstorming, and we were amazed to see that 842 built pretty much exactly what we had been thinking about. We like our actual design better, but it was cool to see the other one executed really well.

Re: 2015 2nd Choice Robot
 

Do not despair. As a driver in 2013, I can tell you that with enough practice a decent driver can align with a very small opening at full speed. It's a good idea to make the design as easy as possible for drivers though. :/

Re: 2015 2nd Choice Robot
 

Indeed, holonomic drives (like mecanum, speaking as a coach that did swerve with this guy in Einstein 2013) also take practice lining up consistently at full speed. There's no one best answer for all drivers even within the same game.

The cool thing about a lot of these drivetrain ideas is that you can still do them later. Off-season work can answer a lot of questions and provide a lot of practice with things like mecanum, slider wheels, and chassis shapes. Maybe they won't think it's too hard next time. ;)

Re: 2015 2nd Choice Robot
 

We didn't really have a "second choice" this year. We tossed around a bunch of ideas, including traditional forklift (with and without tilt, with and without sliding arms), those which surround the tote and pick it up like a boat lift, active pickups, and something with several one-game-piece pickups (along the lines of, but not as cool as 5637's turntable). However, except for the general design we selected on kickoff day (a first by well over a week), each of them was at least one of:

• unable to mine the landfill without making a mess
• required too many trips
• required too long to make stacks
• Could not handle RCs
• beyond our manufacturing capability -- our high-precision tools are:
  • a chop saw
  • a beat-up drill press
  • an aluminum welder at a mentor's garage
  • a loaner table saw that came in about week three

Re: 2015 2nd Choice Robot
 

That was a huge challenge, we decided to mount electronics vertically to make room for the Omni H pattern... figuring out how to mount middle was a tough challenge and also getting the robot level afterwards ... we then figured the middle needed a suspension to stay in contact with other four corners. It took us 4 weeks just to get the drive train working. Rest of robot assembled in two weeks.

I do believe Omni's will prove to be the best for this game. The results were totally worth the effort. Far exceeded what we envisioned.

As for what we were thinking originally .... we spent a long time looking at a robot that could load from the back and in place rotate totes to the front hopefully scoring.... that was nixed in favor of a simpler more robust design tht did not require placement to work.