Brushless B4

[Sylvester]

Hey guys, im gonna go BL in my B4, but was wondering what setup to take for it? I was thinking a 1920/1930 with a quark 80B but was wondering what turn/size of lehner? Thanks guys, BTW im running 6 cell packs.

[BrianG]

I assume by "6 cell", you mean 6 NiMH?? If so, why not use the MM ESC? It's smaller, more powerful, computer programmable, and cheaper.

[Sylvester]

Yes, 6 Nimh. I was thinking of using the MM esc, but what motor? I would love to run a lehner in it for the greatest efficiency. Thanks.

[aqwut]

Well, how many RPMS are you planing to get?

get the mamba maxx.. it's cheap, and reliable....
if you want high rpms.. it's difficult to get high efficiency with 7.2 volts...
for example, say if you got the 1930-4 HiAmp(5225 kv) version.. you would only reach 90% efficiency at 90+ Amps...

[Sylvester]

Im not sure what RPM i want, id want somthing equivilant to a 15 T brushed motor, just dont want it to run too hot. Thanks. MM esc it is.

[aqwut]

Not sure the kinds of rpms brushed 15T motors gets....

[Sylvester]

I was thinking of the MM combo, the 4600 pack, think this would run for a 5min main on GP3700 packs? Or would you reccomend a higher kv? Or maybe a better motor? thanks. The brushed motor gets 31,750 RPM. This is the motor i was supposed to use. http://www2.towerhobbies.com/cgi-bin...?&I=LXJAJ4&P=7

[aqwut]

you should last 5mins without a problem...

[Sylvester]

So what you think, 4600, 5700 or 7700? I was thinking 4600 for longest run time, but the 5700 will give me a nice balance between both. So its either the 4600 or 5700.

[BrianG]

Well, you could try the new version of the R/C Calculator to see what motor it suggests. Just go to the Motor Selector page. Besides, I'm curious to see what it says for real-world applications...

[Nick]

The 4600 and 5700 will run for over 5 minutes easily. The 5700 is a really nice speed on 6 cells.

[Finnster]

5 min on 3700 in a light little B4 should be easy.

I would def go w/ the MMax over the Q80. If you really want a high eff motor you could look at the Neu's as well. I have a 380C-6L in my heavy rustler and I really like it as well, this could be an alternative to the 5700. Loads of Tq, fast spool and should easily do 40 mph in the B4 and give ~10 min run on 3700s.

You don't hear about these as much now the MMax systems have come out, but its not bc they are not great motors. The mamba have just kinda taken over everything since they are sold as a system.

[Sylvester]

Ive decided on the MM 5700. Hope its not too much power on the track. What would be a good place to start with gearing? Ive got an 81T spur.

[aqwut]

use the speed calculator dude... trial and error is the best way....

[captain harlock]

I had a b4 in the past and I can give you some help.
With the 5700 motor, which is almost equivalent to a 10-11T brushed motor, I recommend you to start from 19t pinion and go up from there.