Killer Bees - 2014

[Akash Rastogi]

That driver is looking solid already. Very nice!

[kenavt]

Originally Posted by Akash Rastogi

That driver is looking solid already. Very nice!

It's their driver from last year, so she has some experience already.

Along with the rest of the all-female drive team, dang...

[AllenGregoryIV]

This is stunning, great job 33.

Is the deflection shot off the collector going to be a regular thing? I love it.

[ttldomination]

Super solid.

Mind sharing your shooter releasing mechanism?

- Sunny G.

[BJC]

Originally Posted by AlecMataloni

Hard to tell, is that Nonadrive or Butterfly? Looks slick!

I plead the fifth.

Originally Posted by AllenGregoryIV

This is stunning, great job 33.

Is the deflection shot off the collector going to be a regular thing? I love it.

Every time you see it truss or shoot from in close we are deflecting the ball off the arm - so yes.

Originally Posted by ttldomination

Super solid.

Mind sharing your shooter releasing mechanism?

- Sunny G.

We are on team choo choo this year. Unfortunately, I don't have any good pictures. Maybe I'll throw something up after Week 1.

[Agentarrow]

I have to wait all the way until Troy to see this thing in person? You guys are killing me.
Looks like some familiar faces are still around though, which is always good to see. Spectacular job guys. I don't think it's Buzz's prettiest incarnation, but its so brutally effective that I don't even care about looks.
Good luck out there, can't wait until we play together.

Edit: I don't think my wording is very well chosen here. This is not intended as a backhanded compliment with an attached insult, I just simply meant to state the truth about my thoughts on the robot. It's not as pretty as your 2012 or 2013 robots, but that's not a statement on this robot beingvugly, it's just that those are a tough act to follow aesthetically. As I said before though, I care more about function than about appearance and this machine does everything it needs to beautifully. That is worth much more than how it looks.

[TravusCubington]

dat #zjshuffle doe

[Squeakypig]

Originally Posted by BJC

We are on team choo choo this year. Unfortunately, I don't have any good pictures. Maybe I'll throw something up after Week 1.

Real Question: Did you choose the Chug Lyfe or did the Chug Lyfe choose you?

Translation: Was the choo choo shooter your first selection of "winch" mechanism or were there other iterations you went through?

[apalrd]

Originally Posted by Squeakypig

Real Question: Did you choose the Chug Lyfe or did the Chug Lyfe choose you?

Translation: Was the choo choo shooter your first selection of "winch" mechanism or were there other iterations you went through?

We chose the Chug Lyfe based on our experience designing other mechanisms in 2010 and the forces involved in releasing winches. The choo choo has had its share of design iterations, as there is a lot of concentrated force in a small package.

There's quite a lot into the design of that choo choo, the geometry of it, and the gearbox.

[XaulZan11]

Since you already competed, can you share info about your drivetrain?

[BJC]

Originally Posted by AllenGregoryIV

Congrats on the win at Southfield.

What are you all using for a "photon cannon" this year and what exactly are you using it for? Normal aligning to wall?

Thanks, we are generally happy with the robot performance this weekend.

The flashlight basically provides a line on the ground in front of the driver which allows us to line up with stuff on the field from far away. When we initially put the light on we immediately saw an improvement in driver performance. I contribute this to the driver being able to look at the light instead of the robot while driving. Effectively, it becomes intuitive to look where the robot is going to be rather than where is currently is.

Originally Posted by XaulZan11

Since you already competed, can you share info about your drivetrain?

The drivetrain this year is actually has a pretty interesting story behind it. I don't have time to properly do it justice right now, but maybe sometime later this week I'll type it all out.

[Answer42]

Originally Posted by nathannfm

I spy an Omni wheel!


The drivetrain this year is actually has a pretty interesting story behind it. I don't have time to properly do it justice right now, but maybe sometime later this week I'll type it all out.

So.... About that drivetrain.

[s_forbes]

Originally Posted by Answer42

So.... About that drivetrain.

This is one of the first mysteries that I set off to solve when I got to the pits in St. Louis. The answer surprised me: 4 omni wheels, each with a single gear reduction from a CIM motor, nothing more. I chatted with one of the students as they were going through inspection, and the rational for the design choice sounded reasonable. The consistency and range of their catapult seems like a big part of why they are so successful with this approach.

[apalrd]

About the drivetrain:

The drivetrain is very simple. There are 6 pieces of sheet metal (0.050" 6061 T6) which make up a fairly standard square with 2 wheel bays of approximately standard width (I believe 3", don't quote me on that). At each corner, a stiffener plate (0.050" 6061 as well) is used to maintain the center-center distance between a single large CIM with Vex 11t pinion and the Vex omni wheel and 72t gear (held together with versakey parts). The axle is 1/2" 7075 round, dead, taped in the end for a 1/2-20. I can give more details on the exact fabrication if you want.

The omni wheels were replaced every 2 tournaments or sooner, we simply replaced the entire axle-bearing-wheel-gear assembly and had a complete set of identical spares (including axle spacers) in the pit.

We found that the CIM could twist, so we added wood blocks between the CIM and front/rear chassis rail to keep the gear spacing correct. This was done manually by sound, the whole drivetrain is very quiet when running.

We initially used Vex encoders with Vex 2.75" omni wheels as floating odometry wheels, but quickly removed them for weight savings and ran time-based autonomous programs (we did do voltage compensation to try to keep it reasonably consistent). There are no sensors in the drivetrain.

The catapult is a single welded frame, which bolts on top of the chassis to provide significant stiffness. With the 4-omni drive, we don't care about stiffness nearly as much as we did with drop-center traction wheel drives.

The strategy behind the drivetrain was basically to be able to maneuver out of any situation easily enough to prevent direct pushing. We believe this achieved it in the lights, simplest way possible, without any articulating systems. By preventing direct pushing, we also removed the need for a multi-speed gearbox, allowing the 'corner modules' which are extremely light, simple, and efficient.

I can answer more questions if necessary.

[Zebra_Fact_Man]

Are there any better pictures of the drivetrain system posted anywhere?