Re: aluminum heatsinks?
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The current that flows through the tabs surely is the full motor current draw. So theoretically the lower the resistance between the PCB and the motor the better the performance would be.
Oxidisation, even a greasy fingerprint can be enough to increase the resistance of the contacts. In an ideal situation you would have a soldered connection between the conductors from the PCB and the motor case. Obviously this is a fairly dificult thing to do, but perhaps not imposible.
The cross sectional area (greater CSA = lower resistance)of the wires from the PCB to the tabs is relatively small so there may be minimal gains made by increasing the size of those wires.
As you said Jamie, the current is small, and I guess that in the big scheme of things it is. I’m an Electrician – Instrument tech by trade and regulary work on BIG industrial gear, with electric drives up to 3000 hp, so these are small yes.
The batterie/s in a Bit are only rated at what 100mAh up to perhaps 200mAh, that is milliamps per hour. So if I remember correctly, the battery in theory will deliver exactly that, 100mA for 1 hour at its rated voltage.
The PEAK amount of current available from the cell/s is actually MUCH higher. Short out a batery and tell me how hot it gets!! A lot more heat than 100mA will give yo thats for sure.
So if the motor is the item that draws the most current then improving the supply to it should make it go better.
If you look at say the 1/10 scale electric cars, most of them run say a 1200mAh (1.2 Amp) 7.2v pack, but the Electronic Speed Controllers are often rated for currents up to around 80 amps. And those cars never run for an hour. 5-10 minutes would be a good run for some of them. Likewise, a Bit doesnt run for an hour so it definately draws more than 100 – 150mA.
Gold plated contacts would improve things marginally, so would a gold plated motor, both plated, even more again I’d guess. Even tinning the motor case and the contacts with solder may improve the contact area and give you minor gains.
Whatever you do, the improvements would be fairly hard to distinguish over standard.
8ch Ess Vee
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