(10-Sep-2002) Now that the NDA is off the prelims, we can report with sadness that SnowCone lost its first fight with BullDog.
(11-Aug-2002) Because SnowCone was so vicious, we were never able to test its weapon before putting it in the box. We were very happy with its destructive force, but disappointed that BuillDog was such a tough opponent.
Today we took the newly repaired SnowCone to the Lazy Toad Robot Club both to demonstrate its spinning weapon, and to show the arena builders why you need an arena to test.
Click on the image to the right to view the Video of SnowCone vs the Ink Jet Printer (3.9 mb RealMedia).
As you can see, SnowCone is exactly at 60.0 pounds. We even had enough weight left to add a hose clamp to the back of the MagMotor to hold it steady against the rear bracket.
We also got the Dean's Antenna mounted. We moved it from the back panel to the left side channel, with the wire sticking up through a hole in the Lexan. This way, no pur side impact can affect it.
To the right, you can see the blade in motion...the flash still stops it, but it's strangely transparent because it was moving between 4,000 and 4,500 rpm.
(19-Apr-2002) Got SnowCone reassembled after painting. We are very close on weight, so we couldn't afford to put aluminum on the top/sides. So we cut a couple of triangles of 3/16" Lexan and made tabs on the sides that could be bolted to the top and front plates.
We also added a couple of wdege/spikes to the front sides of the robot (these are just small triangles of 3/16" 6061 aluminum). These mainly serve to increase stability and prevent the blade from hitting the ground when the robot pitches forward after hard braking.
Here you can see the brackets holding the NPC 2423 motor and 4-1 reduction gears. To the right you can see the 4" MagMotor C40 bolted to the front plate with 4 5/16" stainless steel bolts. The front plate is 3/16" 6061 aluminum.
Here are the guts. The Vantec RDFR23 is mounted against the side wall in a sandwich of foam rubber. Debbie was nervous about the spike strips piercing the electronics, so to the right you can see my fix: a piece of 0.100" grade 5 titanium bolted to the ouside wall.
To the left you can see the 3 strings of 3 7-cell packs of Nickel Metal-Hydride batteries. That gives SnowCone 9AH at 25.2 volts. The weapon is controlled by a White-Rodgers 24 volt contactor to the right of the Vantec. The master switch is mounted at the back...its a Cool Robots switch from Team Delta.
Now all we have to do is trim 1/2 pound, mount the Dean's antenna, and we're set for May.
(16-Apr-2002) Today we got the blade cut and mounted. We went with 17.5" giving us about 3/16" of clearance between the blade tip and the ground. We're using a Dalton torque limiter (with some secret modifications) to attach the blade directly to the MagMotor's 5/8" shaft.
Fuzzy cranked the blade up to full power in the garage, and the balance was fine. The bad news is that we'll never know the exact rpm's, because Fuzzy isn't willing to get within 15 feet of SnowCone when the blade is turning. Based on the measured speed of the 30 pounder at 3,030 rpm, and given 50% higher voltage, we calculate a blade speed of 4,500 rpm, or a tip speed of 234 mph.
Once we got the bot working, we took everything completely apart and applied the paint, grey automotive primer and glossy blue to match Ice Cube (since we have two lightweights and two middleweights, we have a separate team called "Toad-Crystal" with blue robots).
So all that's left is to reassemble the robot and add two triangles of 3/16" Lexan to cover the sides.
Be afraid...be very afraid!
(15-Apr-2002) Debbie's vicious little propeller spinner bulks up for BattleBots in May 2002 as a lightweight. The new SnowCone is wider, taller, and meaner. The photo on the left show the size comparison between the 30 pound version and the 60 pound version. We haven't mounted the blade yet, so we put a piece of 3/8" X 2" chromolly bar in the photo for inspiration. The blade will be about 17" long and weigh only 4 pounds.
The frame is a welded unibody of 0.190" 6061 aluminum base plate and top, 0.375" aluminum front plate, and 0.125" side walls. Fuzzy welds aluminum a lot like Toonces the cat drives... Fuzzy can weld aluminum, just not very well. In the top photo, Debbie shows Fuzzy how it's done.
Here's a closeup of the motor mounts. We're using the NPC 2423 motor kit with the 4-1 reduction gear and 5" wheel.
The outside wall is made of 3" x 1" 6061 aluminum channel 1/8" thick, and welded in place. The interior plates are held on by four 1/4" bolts.
To the right you can see the bottom with the two double-hung wheels and a UHMW polyethylene skid plate at the back. The wheels are about 14" apart, making this version of SnowCone a little tippier than the 30 pounder...but we've got the batteries low to keep the center of gravity as low as possible.
Next we cut the blade and mount it on the Dalton Gear torque limiter.
The new blade will weight 3.6 pounds (up from 1.75 pounds for the smaller bot), will be 5" longer, and spin 50% faster (about 4,500 rpm) with 9 amp-hours and 25.2 volts compared to 6 amp-hours at 16.8 volts.