Since we had a few days until Vegas, we decided to stress test the Bot by driving it up and down the gravel driveway. We demonstrated at least 500' range on the radio with the 6" Dean's antenna, but afterwards one of the wheels was wobbling.

The problem turned out to be one of the bearings on the NPC 60522 motor. A side load generated when one of the wheel's cotterless pin fell out caused the bearing to pop out of its hole.	Our solution was to cut 4 bushings to fit over the motor mount rod, and a couple of 3/4" steel pipes to fit between the motors. The combination of bushings and pipe should give the bearings no room to pop out.

Upgraded motor mount scheme

So once again, we are ready to pack up for Vegas. We leave Wednesday evening.

We completed shockmounting components using foam rubber and mousepads. The two boxes with the mousepads hold the two Vantecs. The batteries are held in place by adjustable nylon strapping. Taking a cue from Mauler vs. Killerhurtz, we tiewrapped the Futaba receiver.	We mounted a steel cover plate over the master switch. The LED runs off the Futaba receiver battery, so we can be sure the receiver has power after the cover is bolted on. We read a horror story on the Forum about a builder who forgot to turn his receiver battery on and was torn to shreds by his opponent.

Here's the completed FrostBite: 4 NPC 60522 wheelchair motors (24 volts nominal) running at 41.6 volts 2 pairs of DeWalt 18 volt XR+ batteries 2 Vantec RDFR-33s speed controllers. Futaba FP-8UAP75 PCM on Channel 87 (75.930 MHz) FrostBite's blade is 38" wide and 9 1/2" tall. The body is 30" by 18" wide by 6" tall. The wheels are 9 5/8" in diameter. Current weight is 206.5 pounds.	Here's Fuzzy riding on the completed FrostBite. For fun, Fuzzy and Debbie rode around together on FrostBite. We plan a team group photo, and believe that a robot should be able to drive its whole team around.

Biohazard's view of Frostbite

Danny decided to build his own flyweight robot called LockDown .
It weighs less than a pound and is powered by imagination.

Debbie's horse Gizmo looks on as we drive FrostBite down to the barn .

Yesterday, Fuzzy was visiting CMU's Robotics Institute, and saw some signs of a robot revolution

Today we painted the body orange , the children added teeth to the shovel

Got 2 sets of 4 DeWalt 18V XR+ packs purchased, so I have a spare set that can charge while FrostBite is crunching metal.

I prepared a weight distribution pie chart .

Basically, after the Las Vegas competition, I'd like to reverse the percentages for weapon (now 10%) and wheels+hubs (now 23%). The body could be lighter, but we'll see how well 58 pounds of steel holds up in Vegas before deciding whether we have too much or too little armor.

After reading the threads about DeWalt NiCad batteries, I decided to try a set. FrostBite was running with 4 5AH 12volt gel cells, giving 10 AH at 24 volts (weighing 16 pounds).

With four DeWalt 18 volt XR+ packs, we have 4.8 AH at 41.6 volts (weighing 13 pounds). We verified that FrostBite can run for at least 8 minutes flat out using the DeWalts.

To make sure the Vantec RDFR33's don't blow, we used two, one for the front wheels and one for the back. One side benefit is that we have completely independent power and control for the front and rear pairs of wheels. So no one blow from a huge spike can immobilize FrostBite: you guys will have to hit it at least twice.

The extra voltage sure makes FrostBite a lot peppier.

Here's the photos:

Front view 10/24/00 Top View 10/24/00

FrostBite Spinning 10/24/00 (1.9 mb AVI)

Today we installed the motor capacitors and passed the office floor smoke test .

We also had our first driving test , and the results are impressive.

We have some videos available from today's tests:

Stationary object test (3.1 mb AVI),   ATV test (4.9 mb AVI)

Weight carrying test (1.8 mb AVI)

The bump test showed we need to beef up the battery mounts; the impact broke the tie-wraps holding the cardboard boxes to the axle. Today's test did show that the Radio Shack gel cells will power FrostBite for 8 to 10 minutes before losing steam...they also showed that FrostBite has enough traction to push a whole shovel load of gravel up and down the driveway.

We are considering switching to a more advanced battery system. Instead of 24 volts, we may try 30 or 36 volts to improve ramming impact. But first, Team Toad is going on vacation (it's important to be well rested for these competitions). Don't expect any more posts until early November.

We also managed to reserve our hotel rooms in Las Vegas. Thank heavens that I had the foresight to be on Caesar's Palace's VIP list...they're even sending a limousine to convey FrostBite to the arena.

All the motors, hubs and wheels are mounted and the snowplow blade is attached. So you can now see the external view of FrostBite:

FrostBite side view FrostBite front view

FrostBite back view FrostBite weight test

We've had to lose the big black spiked bar on the rear end because of weight limitations (we're at 208.5 pounds), but at least we have enough margin to attach the wheel spikes. With luck, we won't need more than 1 pound of wire to hook the motors to the speed controllers. Tomorrow we wire up the Vantecs and the Futaba. Just have to remember to move the car out of the garage before firing it up.

First and most important, all ordered parts have been delivered:

• Vantec delivered 2 RDFR33 controllers 15 days after they were ordered. Way to go, Vantec!
• Vantec also delivered my 8 channel PCM radio.
• All Metal Fabricating delivered the custom wheel hubs and spikes for the mower wheels.
• Team Delta delivered the e-switches and actuator controllers.
• Radio shack delivered the high amperage terminal blocks, and finally
• Flaming River delivered what has to be the world's largest battery cutoff switch, a 250 amp switch rated for 2,500 amps for 5 seconds.

Work is progressing on the NPC 60522 motor mounts. We're using 1/2 steel rods

cut with a ginder and sanded on the drill press .

The wheels are attached to the motor shafts with custom made steel hubs bolted to the wheel walls and double pinned to the motor shaft.

The machinist who made the hubs got into the spirit of the competition, and made four steel spikes to protect the wheels from flanking maneuvers.

Work this weekend:

• Attach the motors to the steel body
• Hook the speed controllers, batteries, and receiver together temporarily
• Have the first driving test with the new wheels.

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