spinningmagnets wrote:Just figured out the Castle Creations USB data-link. It is free.
Voltage-ripple- Fortunately, I ordered the ICE line (8S/28V) instead of the ICE-Lite (6S/ 22V). They both come with power-input capacitors, but they are sized to help a model aircraft instead of a heavy E-bike. I was getting enough voltage ripple (4V-ish ?) that I need to install a couple low-ESR caps ($5), and the extra ESC voltage capability probably helped me avoid popping something inside the ESC.
what happened to the ripple voltage after the extra caps were added?
Kepler! if your out there ... How did your launch ramp work out ? Adien's seems to work fine with out it... Happy Easter to all... Bill
Volt / kV-speed chart
For available 63mm motor kV's
1.0" and 1.25" roller diameters
The kV that is listed for a motor, is the RPMs resulting per volt applied. Many factors affect the actual road RPMs in use. The weight of the bike, rider, and cargo is a major factor, and also wind resistance and system friction. In the past, many have found that reducing the kV number by 15% can be a useful (though approximate) way to arrive at a calculated speed which is close to the actual resulting road-speeds.
I have compiled this chart as a rough guide to selecting a motor kV and system voltage. The top number is a 1.0" diameter roller and the bottom number is a 1-1/4" roller. LiPo and LiMn cells have a nominal voltage of 3.7V (and 4.1V when fully charged). Six of them connected in Series (6S) creates a cell-string that will have a nominal voltage of 22.2V; When fully charged, the string will have a voltage that is closer to 24.6V
Edit: I still have the original chart, but it has proven to be off some. I have developed two drive systems that both operate at arount the federal speed limit for unlicensed mopeds, which is 20-MPH (of course, the federal limit does not apply in those states where a higher speed is allowed)
Both are using the Exceed 295-kV motor. For flat land I am using 24V of SLA and the 1.25" roller, and for hill climbing, I am using 37V of LiPo and the 1.0" Roller. For the hill-climber, I am also adding more capacitors and a heat-activated air-cooling fan.
If you chose to use 44V-48V, the available kVs of the 63mm motors would provide you with a very wide range of top-speeds, with the 295-kV providing an estimated 27-MPH.
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