Team Toad: SnowCone 30

This page describes SnowCone, Debbie's 30 pounder originally built for iHXRC.

(15-Apr-2002) Check out the newer, bigger, meaner SnowCone LW page. Debbie's taking SnowCone to BattleBots.

(25-Mar-2002) SnowCone got 2 wins, including 1 KO, one forfeit and two losses at HSRC'02. Debbie gave us a new tag line in her fight with EMF:

(16-Feb-2002) Although SnowCone made a good showing for itself at iHXRC, knocking out Metal-n-Lace before losing to Paladin, we decided to make a few changes for HSRC. One weakness was the 3.6V B&D cordless screwdriver motors. The fight with Paladin turned into a pushing battle, and the gears in the screwdriver transmission started to get "crunchy". Then, our Vantec popped a nutsert which shorted out one side. We lost the fight because of a weak drivetrain. Then we couldn't get back into the loser's bracket because changing a motor required removing too many parts to make the repairs in 20 minutes.

On teardown, even 6 months later, we're still finding sawdust left from Paladin on the sticky tape on the bottom plate.

Taking a cue from Andrew Lindsey, we chose to upgrade to 24 volt motors from the Surplus Center. They are heavier, but since they run at higher voltages, we won't need a separate power supply for the drive and motor. Dropping one RC battery pack saves about a pound, which is almost enough to fit the bigger motors. The wheels and hubs come from Cruel Robots.

We needed to save a little more weight to get the motors to fit, so we replaced the Vantec RSFR48e controlling the MagMotor with a White-Rogers 24V relay. The Vantec gave fine control and allowed reversing the blade, but a robust drive was deemed more important.

The final wheel mounting is shown in the title photo at the top left. As an added bonus, the new motors are neutrally timed, so we also eliminated SnowCone's bad tendency to steer to the left.

(26-Jan-2002) Debbie was the last member of the family to get her own robot, but in many ways, SnowCone is the most extreme robot Team Toad has ever built. The engineering challenge was to fit a 12 pound weapons motor more suited to a 220 pound BattleBot heavyweight into a competitive NERC robot weighing less than 30 pounds. The result is an extremely powerful, aggressive spinner whose only weakness is an underpowered drive train. For 2002, we’re upgrading the two front motors, hoping to keep the whole contraption within legal weight.

• Robot: SnowCone
• Weight Class: 30 lb.
• Weight: 29.7 lbs.
• Physical Specs: 14.0” wide, 20.0” long, 9.0” tall, with a 0.5” ground clearance.
• Offensive system: a steel propeller spinner 12.5” long, weighing 1.75 pounds driven by a 3.8 horsepower MagMotor at 3,030 rpm.
• Defensive system: top armor is 0.038” 6-4 titanium, sides are 3/16” polycarbonate, and the bottom and front are 0.13” 7075 aircraft aluminum.
• Navigation System: Futaba FP-R148DP 8 channel micro receiver operating on 75 MHz, controlled via PCM1024 modulation from an 8UAPS 8 channel radio transmitter.
• Drive System: two 2” diameter Colson rubber wheels driven by Black & Decker cordless screwdriver motors at 8.4” volts. Power is supplied by a 35 Panasonic NiMH cells, and moderated by a Vantec RDFR23 electronic speed control.
• Win Record: 1 win, 1 loss at CJRC’01.

(07-Sep-01) Okay, after a very full day of painting and reassembly, SnowCone is ready for the Chicago competition. Weight is 29.81 pounds. Next week: we post the results. The photo at the left shows the whole Tiny Toad fleet.  

(04-Sep-01) In spite of suggestions from the forum that having Debbie drive topless would be a crowd pleaser (and who could argue), we decided we needed something for SnowCone to wear, and decided the next sexiest material is...6-4 Titanium.

The photo on the left shows a frame of aluminum angle with a trapezoidal top made from some scrap TI-6-4 we had laying around the ranch. Tomorrow McMaster will deliver some Lexan we'll use for the sides. So the top will be somewhat see-thru.

The photo on the right shows the front view. Note that the safety cage only covers the electronics in the back. We figure the spinning blade will be enough armor in the front.

(03-Sep-01) We had the first driving weapons test of SnowCone yesterday. The blade weighs 1.75 pounds, and rotates at 3,030 rpm. The startup current is 90-100 amps, and the blade reaches top speed in under 1 second. As you can see from the photo on the left, we have about 3 pounds left to put top armor on the robot.

Debbie did help with the cutting and drilling.

(28-Aug-01) We got the wheels mounted to the motors (2 3.6 volt B&D cordless screwdriver motors). There was a question on the forum, so here's a couple of photos. Basically, we use a Dremel to cut a big keyway in the shaft, a jigsaw to cut a keyway in the 3" Colson wheel, and we grind a 1/2" steel washer to make an oversized Woodruff key.

We use 7/16" split shaft collars to hold the wheel and key combination on the end of the shaft.

The photo at the top shows the prototype drive system ready for driving practice. The current weight is 3.75 pounds, leaving us 26.25 pounds for weapon and armor.

More details on the weapon will be coming shortly. For now, we can tell you that SnowCone is a spinner combining features from Hazard, Bender, 911 and Hypnodisc.