Cathi

Cathi
Year Of Creation	2013-2014
Versions
Current Version	2.1
Update Year	2014-2015
Information and Statistics
Weight Class	FeatherWeight
Weapon Class	Ring Spinner
Wins/Losses	0/5
("Temporary")	("Temporary")
("Temporary")	("Temporary")

Cathii is a 30 pound invertable ring spinner robot.  A ring spinner design was chosen because it allows and offense on every side of the robot, while still being invertable.  The ring design allows weight normally dedicated to the armor of the robot to be dedicated to the weapon, thus increased the power of the weapon.  Her ring is approximetly 15 pounds and spins around 2500 rpm at top speed.  Cathii has be undergoing continual improvements every year since her first competition in 2014.

Competitions

Motorama 2014

• Results:
  • Bracket Style:
    • Loss vs Pitter Patter
    • Loss vs Candy Paint and Gold Teeth

Motorama 2015

• Results:
  • Bracket Style:
    • Loss vs Pitter Patter
    • Loss vs Candy Paint and Gold Teeth
• Results:
  • Bracket Style:
    • Loss vs Drum Thing Else
    • Loss vs Triggo
  • Loss in Featherweight Rumble 

Motorama 2016

• Results:
  • Bracket Style:
    • Loss vs megatRON
    • Loss vs The Robot Formerly Known as Drumthing
    • Win vs Gracious Pipefessionalism

Version

Cathi V1.0

Desgined By: Max Carlson

Cathi was first designed and built during the 2013-2014 school year.  

Drive Motors	RS-545
Drive Motor Controllers	Ragebridge 1.0
Weapon Motor	NTM 5050
Weapon Motor Controllers	TURNIGY K-Force 120A-HV OPTO
Reciever	Turnigy
Remote Control	Turnigy
Battery	Turnigy Nanotech 8s 5000mAh

Problems:  

• Drive Motors are over volted
• Weapon ESCs burned up
• Weapon Belts would bind and stall out the weapon motors
• Overall weight was heavier than the estimated weight(weapon aluminum inserts were removed to account for this)

Future Changes/Improvements:

• Decrease the main robot voltage
• Look into new weapon ESCs
• Redesign weapon motor system
• Use more powerful drive motors

Cathi V1.1

Very little changes occured in this second iteration.  The majority of parts were reused, with some being altered.

Drive Motors	RS 550
Drive Motor Controllers	RageBridge 1.0
Weapon Motor	NTM 5050
Weapon Motor Controllers	TURNIGY K-Force 120A-HV OPTO
Reciever	Turnigy
Remote Control	Turnigy
Battery	Turnigy Nanotech 6s 5000mAh

Problems:

• The RS-550s performed better than the RS-545s, but still burnt up
• The Weapon motor controllers continued to burn up
• The inner pulley diameters were decreased to keep the belts from binding.  This resulted in under tensioned belts which failed to transmit the force of the motors.

Future Changes/Improvements:

• Program the Ragebridge/Tranmitter to limit the motor voltage
• Use new weapon motor controllers
• Change the weapon motor system
• Change the weapon mount system

Cathi V2.1

Designed By: Ethan Bisgaard

Cathii was completely redesigned from the ground up.  Some of the design goals were reducing the overall weight and accomplishing that overall weight, redesigning the weapon system, and improving the electronics system.  When fininshed, the entire robot shrunk by approximetly 1" in diameter and was estimated to be 28 pounds.  The actual weight ended up being 29 pounds accomplishing our first goal.  For the weapon system, the weapons mounts were completly redesigned, and we switched to a teardrop wheel drive instead of a beld drive.  The new weapon mounts are a custom built tapered roller mount which increased the load ratings, while eliminating the friction seen in the previous pulley design.  The idea behind the teardrop wheel is similar to a centrifugal clutch; as the weapons spin up, the wheel would expand to contact the inside face of the weapon ring.  Both of these designs accomplished our second goal.  Finally, we changed the electronics of the robot.  For the drive system, we programed the drive controls on the trasmitter for a maximum voltage of 16 volts instead of the max volts of our robot(22 volts).  This kept our drive motors from overvolting and burning up.  We also used a new weapon ESC, the Toro TS 150a.

Cathii accomplished all design goals set out.  All aspects of the robot worked as expected except for the teardrop wheels.

Drive Motors	RS-550
Drive Motor Controllers	RageBridge 1.0
Weapon Motor	NTM 50-50
Weapon Motor Controllers	Toro TS 150a
Reciever	Hobbyking
Remote Control	Hobbyking
Battery	Turnigy Nanotech 6s 5000mAh

Problems:

• Teardrop wheels exploded under their high speeds and high forces
• The weapon motors burned up either due to high lateral forces on the motor, or prolongedhigh current in the motor.

Future Changes/Improvements:

• Redesign the weapon drive system

Cathi V2.2

Designed By: Justin Ma

Cathiii was modified from the remnants of V2.1. The weapon ring and tapered roller mounts were retained, while the weapon drive was converted back to a pulley system with a rubber drive wheel. The robot ended up being 28 pounds. For the weapon drive, the pulley system consisted of a steel pulley, angular contact bearings, and aluminum end caps that bolted into both the top and bottom plates, and were driven by two 1/8" wide polyurethane belts. A neoprene rubber wheel, cut from tubing, was epoxied onto the pulley. The drive system was kept the same save for the electronics. The RageBridge was replaced with a Scorpion XXL controller and provided unregulated voltage to the drive system.

Drive Motors	RS-550
Drive Motor Controllers	Scorpion XXL
Weapon Motor	Scorpion HKIII-4025-550KV
Weapon Motor Controllers	Toro TS 150a
Reciever	Hobbyking
Remote Control	Hobbyking
Battery	Turnigy Nanotech 6S 2650mAh

Problems:

• Weapon drive wheel detached from the pulley.
• The weapon motors experienced inconsistent loading due to tolerance stack-up of bearings and bearing mounts.