pic: FRC 225 -- 2014 Robot

[Ben Martin]

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[Ben Martin]

FRC team 225, TechFire, presents our 2014 robot, "DJ Fireball". The "DJ" stands for David J. Stickler, a TechFire mentor and NRG Energy Vice President who tragically passed away this past fall. He was a great supporter of FIRST.

TechFire is sponsored by PRESIDIO Networked Solutions, NRG Energy, Penn-Air & Hydraulics, St. Onge Company, Fred Dallmeyer Fund of York County Community Foundation, Leidos, Coupling Corporation of America, Lockheed Martin, ParenteBeard, Vicente Rojas Family, Tekgard Inc., JMT Engineering, Weldon Solutions, the Engineering Society of York, and Penn State York.

Robot:
• 117.5 lb without battery/bumpers
• 27.5” long x 28.125” wide x 48” tall
• Thomas 215ADC38/12 compressor for air generation and 9 tanks for air storage

Drive:
• Eight 4”x1” VexPRO Traction Wheels with nitrile roughtop tread
• VersaChassis west coast drive system driven by #25 chain
• 80/20 brace in middle of the frame for extra rigidity
• 4 CIM motors and 2 Mini-CIM motors driven through VexPRO 3 CIM Ball Shifters
• Geared for speeds of ~4.5 ft/s and 11 ft/s

Collector Arm:
• Rotation actuated by 2 ¾” bore and 3” stroke cylinders
• 3 positions determined by cylinder extensions – one position where the collector secures the ball, one position for shooting, and one position for collecting
• 80/20 collector design keeps collector rigid, low-profile, and easy to tune
• RS550 through a 10:1 VersaPlanetary powers four 2 3/8” BaneBots wheels for manipulating the ball
• Potentiometer tracks arm position
• Arm used for collecting the ball, catching a bouncing or thrown ball, centering the ball for shooting, passing to other robots, and low goal-scoring
• Inspired by many 3-day robots (Ri3D, team JVN, team Copioli)

Catapult:
• Ball launched with 2 2.5” bore and 5” stroke cylinders (Inspired by a 987 prototype--thanks for sharing your prototyping videos!)
• Pneumatic latch allows cylinders to “pre-charge” prior to release, creating an air spring
- Changing the time between pre-charge and latch release provides a variety of launching strengths for different distances from the goal or over the truss (thanks for the idea, 842!)
• Catapult used for launching the ball over the truss and launching the ball into the high goal
• Ball centering control using a photo eye and the collector roller

Catching/Human Player Assist Device:
• Opened and closed with by 2 3” pneumatic cylinders
• Opens on three sides of the robot
• PVC construction allows catching device to flex, dampening impacts with flying balls and other robots
• Catching device mostly used for inbounding from human players—the catching device doesn’t catch robot truss shots very well
• Catching device applies pressure to the sides of the ball after acquisition, allowing for a more-consistent shot due to consistent placement
• Photo eye detects balls thrown into the robot from human players and other robots, automatically closing the catching device when a ball is sensed

Programming
• Homebrewed java program inspired by Cheesy Vision for detecting the hot goal (thanks 254!) (this was done by our fantastic programmer Andrew Lobos while riding to MAR Champs)
• Running a variant of Cheesy Drive (again, thanks 254!)
• 2-ball hot goal autonomous (Also done by Andrew—he did a great job with this, getting it after about four iterations between practice matches)
• 1-ball hot goal autonomous
• 2-ball (1 hot, 1 not) autonomous (for if there is a goalie)

Results
• Springside-Chestnut Hill Winner (from #5 alliance, alliance captain)
• Lenape Quarterfinalist (from #2 alliance, alliance captain)
• Greater DC Winner (from #1 alliance, alliance captain)
• MAR Championship Semifinalist (from #3 alliance, alliance captain)

[Brandon_L]

Fantastic robot.

225 came out of nowhere last year, and its good to see that the group put out another great robot proving they're a true MAR force. It was great playing with and against you the past few weeks, good luck in St Louis!

[Steven Donow]

Originally Posted by Brandon_L

Fantastic robot.

225 came out of nowhere last year, and its good to see that the group put out another great robot proving they're a true MAR force. It was great playing with and against you the past few weeks, good luck in St Louis!

Agreed, the 225 have quickly risen to be one of the top teams in MAR.

Any word on what offseasons you plan on going to this year?

[Ben Martin]

Originally Posted by Steven Donow

Any word on what offseasons you plan on going to this year?

We're on the list for Midknight Mayhem right now. We're going to skip Monty Madness this time, as we really never stopped to take a break since Worlds last year...

If people are free, we may try to participate in as many local offseasons as possible. We'll have new drivers next year, and they will need experience. This all depends on student interest, however. At <$250 each, going to 7 or 8 of them sure sounds like a bargain to me.

We have the manpower/interest to put in an application for the IRI this year--hopefully we'll get in.

Thanks for all the compliments, everyone!

[OZ_341]

I think this team will make a very strong showing at Champs.
Great robot, great people, smart drive team.
No flying under the radar for you Ben.

[Gdeaver]

Techfire been on fire this season.

[nuggetsyl]

That stat sheet misses two huge things.

1. The drivers and HP are with no question in the top 5% of their respective positions. When I played with them adjustments on the fly were flawless and we never shot a truss or in the top goal and still scored 244.

2. 225 drive coach is extremely smart and knows how the game is played. He coaches the team with minimal mistakes and communication behind the glass is fantastic. I can't stress enough how important communications between coaches is, this game more so than others.

[JesseK]

I got an opportunity in DC to watch Ben command his drive team while waiting in queue behind their driver's station. He doesn't say much until it matters - 225's drivers are very smart and talk amongst themselves very well.

[Domenic Rodriguez]

TechFire has an awesome bot once again this year. We had a blast competing with you guys this season. Best of luck at Worlds; I know you'll do great!

[Conor Ryan]

Originally Posted by Ben Martin

Catapult:
• Ball launched with 2 2.5” bore and 5” stroke cylinders (Inspired by a 987 prototype--thanks for sharing your prototyping videos!)
• Pneumatic latch allows cylinders to “pre-charge” prior to release, creating an air spring
- Changing the time between pre-charge and latch release provides a variety of launching strengths for different distances from the goal or over the truss (thanks for the idea, 842!)
• Catapult used for launching the ball over the truss and launching the ball into the high goal
• Ball centering control using a photo eye and the collector roller

Can you go more in depth about this mechanism, I'm having a tough time conceptualizing how it works.

Congrats on a great season!

[Ben Martin]

Originally Posted by Conor Ryan

Can you go more in depth about this mechanism, I'm having a tough time conceptualizing how it works.

I'll do my best--

The catapult arm pivots about an axle ~18" off the floor. Two large-diameter cylinders are positioned such that the end of the catapult arm moves very quickly while still applying the required force. The extension-side of the cylinder vents to atmosphere, making the cylinder extension very quick. Gravity/a slight surgical tubing assist returns the cylinder to its dropped position.

Because the cylinder extension still wasn't fast enough, we added a gate latch actuated by 2 additional cylinders to block the throw of the catapult arm. This allows us to "pre-charge" the cylinders a bit, creating an air spring to increase the speed of the throw. By varying the amount of time we allow it to pre-charge, it adjusts the force of said "air spring" and varies the shot (oddly enough, our most common shot uses a delay of 225 ms).

The catapult foot is made of sheet metal and plastic cutting board material with the tips covered in rubber roughtop. The throw has a lot of backspin, and this helps to reduce it slightly and increases the height of the throw.

Underneath the catapult foot, we have a photo eye detecting whether or not a ball is directly above it. If the ball is too high, we run the collector roller in reverse until the sensor sees the ball--it's a pretty simple way for us to detect if the ball is sitting too high for throwing.

Thank you for all the great compliments, everyone! We really appreciate it.

[Akash Rastogi]

225's driver is phenomenal. It was really cool to see 225 select 2495 this season, too bad the cards just did not play out in your favor. Hopefully 225 and one of the MORTs can team up at Champs!

[nuggetsyl]

In my earlier post I made a mistake there was one truss and one shot in the top goal. But watch how good the 225 drivers are. I would tell them were we were going to place the ball left right etc... and they pick up the ball and hammered them home to finish the cycle. And as you will see, leave them open for one sec and they can shoot in the top goal.

https://www.youtube.com/watch?v=pUxb...nKS4zuu78wn-0g

[silverD]

Congrats on your double win season as well! Your robot and drive team execute this year's challenge superbly.