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View Full Version : Brushless test # 2!!



SweetZ28
10-19-2009, 10:28 PM
Well the 3300KV motor i got did not fair well so i decided to just plop in my noval system with the 4300KV motor I lowered the motors timing and i also installed a ground down CF 35mm custom made prop and will give it a go tuesday and see how she runs... I don't get it that brushless 3300KV motor had no RPM it was 3000 RPM slower than a traxxas titan 12 motor and they are dogs!.

Fluid
10-20-2009, 08:43 AM
There was nothing wrong with the 3300 Kv motor, it performed perfectly. A 3300 Kv motor on 7.4 nominal volts should give around 22,000 rpm under load - this should not have been a surprise. Your 4300 Kv motor will spin a lot faster, probably around 28,000 to 30,000 rpm if not overloaded. Remember that the Kv value varies with manufacturer, some rate it at a different load than others do.

In theory a prop with 2" of pitch should give speeds in the mid-30s. The exact speed and rpm will depend on the quality of the cells, the true Kv of the motor, and the load.



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SweetZ28
10-20-2009, 09:06 AM
Hi the RPM was with no load at all the 3300KV was super slow low reving and the novak 4300KV screams it's like 2 times faster...this is why i put the 35mm prop on...If this works i may just get something inbetween like a 3700KV or a 3900KV.
Thanks

SweetZ28
10-20-2009, 12:10 PM
:thumbsdown: Well just got back from testing ...well looks like the old 3300KV set up was faster the novak 4300KV set up could not push the 35mm prop at all and did not get up to speed. So I am thinking a 3700KV may be perfect or a 3500KV?
Back to the drawing board!

NativePaul
10-20-2009, 08:38 PM
Buying a smaller prop is a valid alternative to buying a lower KV motor and often cheaper.

SweetZ28
10-20-2009, 08:42 PM
Buying a smaller prop is a valid alternative to buying a lower KV motor and often cheaper.
how small can you go...anyhow that novak 4300KV motor screems way...Way to fast for this boat.

Simon.O.
10-22-2009, 05:09 AM
how small can you go...anyhow that novak 4300KV motor screems way...Way to fast for this boat.

Depending on prop choice and cell count I would not write off this as a poor motor choice.
I have a Cat that is a little smaller than the PB Apache and it hauls on a 8S (4400kv) with 2S lipo and a 632 prop.
I have run a lot of other power and prop configurations for speeds well into the 40mph area.
I am now playing with motors and props for more speed.

Your 4300 kv motor is fine if you prop it correctly and set the hull up right. :thumbup1: