Blog - October 2010

VEX Programming Session

Last week, October 26th was our first VEX Programming Session. If anyone hasn’t had the chance to write a sample program or to look at sample code, please do that so that we can move on in the sessions!

If you haven’t downloaded the trial for Robot C, follow the link and start programming:

If you have any questions, please email Zahi Hakim at [email protected] or Bhargava Manja at [email protected].

VEX Tournament: Tracy

Teams 254 A and 254 E are ready to take on the Tracy regional. 254 D is another potential Cheesy Poof team that would want to attend, but is awaiting confirmation from the Tracy director for an extra slot.  254 B, C, H, and S have opted out of the regional in order to get extra time to perfect their ideas before heading into a regional ill-advised.

254 A deploys a “sketchy” at best hanging mechanism accompanied by a claw that has the ability to score and descore.

254 E has avoided the infamous ladder for the time being to focus on their double sided robot.  One side carries a simple spatula to descore while the opposite side of 254 E shows a rolling intake for scoring.

Both robots are tournament ready. There is a scheduled “pack-up hour” for Thursday after school in the Physic’s Lab to collect items such as tools and build material the teams may need for the regional.

San Jose Sharks Street Rally

Team 254’s T-Shirt Cannon made an appearance in San Jose today at a Street Rally for the San Jose Sharks, a professional hockey team.  The Sharks play their first home game today against the Atlanta Thrashers and celebrated the occasion with a pre-game street rally.

The rally was a ton of fun and the robot was quite popular.

Sharks to Host Street Rally

Technical Specifications


  • Ten Barrel Revolver/Gatling Action
  • Automatic Barrel Indexing
  • Motorized Adjustable Pitch – Horizontal to +60 degrees
  • Adjustable Range Control Via Electronic Solenoid Valve
  • Six-Wheel Drive, Off-Road Capable Chassis
  • Wireless Control
  • Capable of launching 3+ T-Shirts per second
  • Also Capable of launching racquetballs or hacky sacks

Technical Specifications:


  • Dimensions:  28″ Wide, 38″ Long, 18″ Tall
  • Weight:  160 Pounds
  • Top Speed:  12+ Feet Per Second
  • Capacity: 200+ Shots per Tank
  • Projectile Range: 150+ Yards


  • Qty 10 – 2.5″ OD, 2.375″ ID Barrels x  24″ Long
  • Globe Motor Barrel Revolver Mechanism
  • Van Door Motor Pitch Adjustment
  • Pneumatic Cylinder Indexing/Lock
  • Gas Spring Assisted Pitch
  • High Pressure SCUBA Tank Reservoir at ~3300 psi
  • Low Pressure Regulated SCUBA Tank Accumulator at ~120 psi
  • 1″ NPT MAC Solenoid Valve at ~17.0 cV Flow Capacity with a 23 ms Response Time
  • Norgren Low Pressure Regulator for Cylinder Indexing
  • H2Oddysey Tank Mounted SCUBA Regulator


  • Power Source:  12 Volt, 17 AH  SLA Motorcycle Battery
  • Controller:  VEX PIC Micro-controller with VEXNet 
  • Wireless Protocol:  802.11 g Wi-Fi @ 2.4 ghz
  • VEX Pro Victor Speed Controllers
  • VEX Pro Spike Relay Modules
  • 12 Volt MAC Solenoid Valve for T-Shirt Launching
  • 12 Volt Rexroth Solenoid Valve for Cylinder Indexing

About Shockwave

In Summer 2010, Team 254 decided to build a T-Shirt Shooting Robot to be used for promotional events.  After two months of hard work, our robot debuted at a spirit rally at our school, Bellarmine College Prep in San Jose.  The robot was received very well and was loved by the students at the rally.

Team 254 plans to use its T-Shirt Cannon Robot to promote the team and its sponsors.  We will be bringing the cannon to team and school events as well as sponsor events.

For detailed information about the design and build process as well as the cannon’s technical specifications, please visit the following pages:

Build Process

Technical Specifications



Bellarmine Spirit Rally

The T-Shirt Cannon made its debut tonight at the Bellarmine Spirit Rally.  Set before the school’s football game against its rival, St. Francis of Mountain View, the rally aims to boost school spirit and morale before the game.

The T-Shirt Cannon came out in the middle of the rally and shot 30 T-Shirts at students stationed across the gym.  The students aimed to catch the T-Shirts in trash cans in order to win spirit points.

The rally was a great success and the T-Shirt Cannon was a huge hit!

Robot Complete

After more than two months of hard work, Team 254’s T-Shirt Cannon is complete.  

Today, we recieved the parts neccesary for us to fill our high-pressure SCUBA tank.  After filling the tank, we tested the robot extensively to determine how many shots could be taken on a single air fill.  On one air fill, the robot can shoot more than 200 shots, well above our initial estimates.

We are very pleased with how the robot turned out and look forward to using it to promote our team, our school, our sponsors and our community.

First Shots

The robot took its first shots today, shooting racquetballs.  The robot shot extremely far, with distances yet to be officially measured.

For today’s shots, the robot’s tanks were filled by a shop compressor in the lab to approximately 100 psi.  Early next week, we hope to start powering the shots off of the SCUBA tank.

Indexing & Tilting

After many days of work, the robot is almost complete.  Today, we completed the indexing and tilting mechanisms and tested the robot in the lab without a projectile.  The whole system seems to be working great.