Thunderhorse

Thunderhorse
Robot	Thunderhorse
Year	2007
Competition	FIRST Robotics Competition

This robot was designed mainly by Keefer Dunn and Patrick Harrington.

Mechanics

Tube System

The tube system consisted of the tube grabber and a tube elevator. Each performed a role in making sure the robot successively could grab a tube and place in gently on the rack.

Tube Grabber

The tube grabber was a small module containing one Fisher Price motor to turn a unobtainium roller that would hold the tube in the tube grabber. The bottom of the tube grabber had flat plastic "fingers" that would support the bottom of a tube as it was being moved up and down during game play. When a tube was taken in, it'd be rotated upward at about a 30 degree angle so the tube could be easily placed on the rack.<ref name="CDBrandon">Brandon Adams' Chief Delphi Post</ref>

The tube grabber would move up in down via the tube elevator by 80/20 wheeled linear slides.^{[Citation Needed]}

Tube Elevator

The tube elevator consisted of the 80/20 supports and the rope winch.

The 80/20 supports that held the tube grabber in place as it moved up and down during game play was actually two long pieces of 80/20. Due to the sizing restriction at the beginning of a match, the two 80/20 pieces would be folded down in the shape of a triangle until the match began. After the match began, a pre-compressed pneumatic cylinder would push up the top half of the structure until it was locked in by a simple locking mechanism thought up of by Sunny Gupta. Pneumatics was no longer needed for the remainder of the match.

The rope winch was a simple winch that was placed at the bottom of the robot with small CIM with a BaneBots gearhead and encoder.<ref name="CDBrandon"/> The rope from the winch went up to the top of the elevator, around a pulley, and back down to the tube grabber. The system only pulled on the tube grabber when it needed to go up, relying on gravity to pull it back down.

During scrimmage, the tube grabber would get jammed in the elevator structure causing the rope winch to put a lot of tension on the rope, causing it to break. It was fixed by using a stronger rope.

Drivetrain

The drivetrain of the robot was a four wheel drive with two IFI "sticky" wheels in the front and two omniwheels in the back.

Control

Picture of the driver station for Thunderhorse with Guitar Hero and XBox 360.

Control of the robot was done by a XBox 360 controller for driving and a modded Guitar Hero controller for manipulation of tubes.

Driving

Driving of the robot was done by a XBox 360 controller using the USB Chicklet.

Manipulation

Manipulation of the robot was done by a modded Guitar Hero controller that was interfaced directly to the digital IO's.

The five buttons on the neck were used for high/medium/low positions for the tube elevator and manual up/down for fine tuning. The strumming on the guitar was used for a manual load/unload of a tube, and the select button was a on/off toggle for the auto-load function.<ref name="CDBrandon2">Brandon Adams' Chief Delphi Post #2</ref>

References

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External Links

• Pictures of Thunderhorse