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Joey · 08:32 PM

I thought I understood how voltage, current, motor kv, gearing, and heat all related but apparently I missed something.

Lemme see if Ive got this right. If I have...

2200kv motor
4S lipo
~33000 RPM

...I will get a particular current draw and efficiency and heat. But say I now keep the same exact gearing and have...

1500kv
6S lipo
~33000 RPM

...the efficiency will increase, and current draw will decrease, right?

Ok, so Ive run my savx conversion stats through an rc speed calculator. Due to a slight design error I cant use a pinion smaller than 17-18T. So assuming I leave the spur at 48T and use and 18T pinion, with the above motor/batt combo I would be geared for ~63mph. Way too fast for me. SOOOO.... say I take combo #2 and change it to this....

1300kv
6S lipo
~28800 RPM

...this would get me to about 55mph. Still a little too fast I think but would keeping the batteries and gearing the same while dropping motor to 1300kv increase efficiency or decrease it due to running at lower RPM compared to the 1500kv? I know these motors make peak power at 35-40k RPM right?

	(#1)
Joey The Big Cheese Offline Posts: 125 Join Date: Mar 2009 Location: Georgia, USA	Gearing, motor kv, and heat question.... - 04.16.2009, 08:15 PM I thought I understood how voltage, current, motor kv, gearing, and heat all related but apparently I missed something. Lemme see if Ive got this right. If I have... 2200kv motor 4S lipo ~33000 RPM ...I will get a particular current draw and efficiency and heat. But say I now keep the same exact gearing and have... 1500kv 6S lipo ~33000 RPM ...the efficiency will increase, and current draw will decrease, right? Ok, so Ive run my savx conversion stats through an rc speed calculator. Due to a slight design error I cant use a pinion smaller than 17-18T. So assuming I leave the spur at 48T and use and 18T pinion, with the above motor/batt combo I would be geared for ~63mph. Way too fast for me. SOOOO.... say I take combo #2 and change it to this.... 1300kv 6S lipo ~28800 RPM ...this would get me to about 55mph. Still a little too fast I think but would keeping the batteries and gearing the same while dropping motor to 1300kv increase efficiency or decrease it due to running at lower RPM compared to the 1500kv? I know these motors make peak power at 35-40k RPM right? Last edited by Joey; 04.16.2009 at 08:32 PM.