PAN003

Using the Novak, Rooster Electronic Speed Controller (ESC) with the SV203

Day 1
I arrived at my local hobby shop with full intentions of picking up a radio (in the RC world the term radio is loosely used as slang for both the radio transmitter and radio receiver) with a trainer port and an electronic speed controller. I was successful in obtaining the radio, but quickly found out I had arrived too late at the store to acquire all necessary items for this project.

Today I arrived slightly earlier and accompanied by my enthusiastic helper Dan. We had plenty of time to pick out some parts we knew little or nothing about. It would be several hours before I would realize that I should have spent a little more money for a bit more versatility. I settled on the Rooster ESC, primarily at the advice of the store clerk based on my telling him that I wanted to go forwards and backwards and was more concerned about torque than speed. I also picked up a Banzai motor, which I notice in the store spun at about 25,000rmp, a little fast. Since the hobby store sold no gearboxes other than what is integrated into the RC cars I had to settle for this and look for gearing elsewhere, at this point I was not even sure if an off the shelf speed controller would work with the SV203.

When I first tried to connect the Rooster to the SV203 it was not behaving as the users manual implied it should, I assumed incompatibility with the SV203 so connect the speed controller to my Futaba Receiver and tested and this seemed to work. Around the same time I discovered a feature of the Rooster called B.E.C. that may have been causing problems. The Rooster is equipped with what Novak calls a B.E.C. (Battery Elimination Circuit), which is basically a 5.7VDC regulator that steals power from the motor battery and supplies it to the receiver and other servos connected to it. Although this feature seems like its nice for use with a RF receiver, it causes havoc when used with the SV203. The first thing I had to do was to break the power lead coming from the ESC so as not to interfere with the power coming from the SV203. Once this was done I could see that the ESC was responding to stop, forward and reverse commands from the SV203. I could also measure the output of the ESC with a voltmeter and see that the voltage was turning off in the center position, and flipping polarities when switching from minimum PWM to maximum PWM.

I had planed to spin the motor with my bench supply, but my standby supply can only output about an amp. I have a 30Amp supply but it is on loan to Dan and since I don't think I will see him in the next few days I decided I needed to invest in a NiCd battery pack and charger. Unfortunately, due to needing a more current, I am unable to yet spin a motor, but I assume that will be resolved tomorrow.

Day 3

It's getting scary; they now recognize me at the hobby store when I arrive.

There were several packs to choose from ranging from about $17 up to $90. I told them I didn't need an expensive pack so they quickly pointed me to the $17 pack. This pack was a six battery 7.2V with 1800mAh capacity. I asked the difference between the $50 pack and this $17 one and I was told that the $50 pack had matched cells and was 2500mAh. I decided that on the lower cost pack and picked up two so that I could charge one while I was using the other. The charger I bought was called a Prophet, and again was chosen at the recommendation of the clerk.

When I arrived home, I charged up the first pack and plugged it into the setup from the day before. Holy Moly that motor can spin, I about jumped out of my chair. Well, it works great.

Next Task: Gearbox