FRC2168 - Behind the Design

[jwfoss]

Many of you remember back in 2006 and 2007 when the Behind the Design books were sold, and the great information teams provided. I feel as though a lot of teams benefited from reading those, as I know that I did.

FRC2168 in an effort to share ourselves with the community has put together segmented posts of the different components of our design. We encourage other teams to do the same.

Our team may have had a rollercoaster of a season, but we couldn't be prouder of what we created. Below you will see individual posts from my blog, if you have any questions feel free to ask. Thanks.

Behind the Design - Scoring Analysis & Strategy (http://jwfoss.posterous.com/frc2168-2012-behind-the-design-scoring-analys)
Behind the Design - Chassis & Superstructure (http://jwfoss.posterous.com/behind-the-design-chassis-superstructure)
Behind the Design - Lift & Hopper (http://jwfoss.posterous.com/behind-the-design-lift-hopper)
Behind the Design - Drivetrain (http://jwfoss.posterous.com/124816511)
Behind the Design - Shooter (http://jwfoss.posterous.com/behind-the-design-shooter)
Behind the Design - Bridge Manipulator (http://jwfoss.posterous.com/behind-the-design-bridge-manipulator)
Behind the Design - Balance Aid Device (http://jwfoss.posterous.com/behind-the-design-balance-aid-device)

A special thank you to all the teams that have inspired us, been our alliance partners, and our opponents.

[Akash Rastogi]

Justin, this turned out sweet! The information is presented in a very clean and organized manner with your blog. Thanks for doing this, and I hope others follow.

[n1ckd2012]

Excellent series! DiscoBots are going to copy you :D

Quick note: The light grey on white body text in the Scoring Analysis & Strategy Document is difficult to read. At least to my eyes.

Well done.

[rocknthehawk]

Wow, fantastic! Thanks for posting/compiling this. A bunch of great info and pictures.

[topgun]

Great suggestions on the roller ends and the channels made from roughtop. I am always looking for ways to do things simpler and faster.

Some questions:
Could you have gone with a thinner sheet metal (.063 or .080)?
How did you handle picking up three balls? Did you have sensors in there to stop the lift until you picked up three balls? (I only saw one stage in the lift/elevator).
Did you actually use the hopper as intended with another robot dumping into your hopper?
What programming language did you use? CAN?
Did you have any issues with the lift motors at the bottom? (I always understood that you can't push a belt)

Thanks for the blog postings and all of the helpful tips.

[jwfoss]

Quick note: The light grey on white body text in the Scoring Analysis & Strategy Document is difficult to read. At least to my eyes.

Thanks, it appears that when you view the presentation in the embedded viewer the colors are off, if you download it, it is much easier to read

Questions below are answered in bold:
Some questions:
Could you have gone with a thinner sheet metal (.063 or .080)?
Perhaps for the superstructure we could have gone thinner, we just went with what we knew worked previously for us
How did you handle picking up three balls?
We kept the hopper open when collecting
Did you have sensors in there to stop the lift until you picked up three balls? (I only saw one stage in the lift/elevator).
The sensor we used (located at the top) was to index the balls for consistent feed.
Did you actually use the hopper as intended with another robot dumping into your hopper?
The hopper was only used for other robots once during competition, however it did allow for human loading as well.
What programming language did you use?
Java
CAN?
At scrimmage and NYC we ran CAN, at CT we ran straight PWM
Did you have any issues with the lift motors at the bottom? (I always understood that you can't push a belt)
We never experienced any problems, our placement of the gearbox was to keep the weight as low as possible.


Thanks for the positive comments, if you have any other questions feel free to ask.

[BrendanB]

Justin,

Thank you for posting this you guys had a phenomenal robot this year, but I'm sure you guys know that! ;) Some very interesting features in your robot this year under the hood I'm looking forward to Battlecry to check them out!

[Chris is me]

Did you have any issues with the lift motors at the bottom? (I always understood that you can't push a belt)

With the belt wrapped around the axle, it's being pulled on one side and "pushed" on the other. Same as if it was at the top.

Awesome robot and awesome information. Thanks for sharing.

[Akash Rastogi]

Foss quick question; for the threaded inserts you used for the rollers, did you drill out the threads/broach and put an axle through or did you thread short axles/use shoulder bolts and loctite those into the threaded inserts and put them on bearings?