brushless rusty speed testing

[skellyo]

Plug in the different gearing values into BrianG's speed calculator:

http://www.scriptasylum.com/rc_speed.html

[Finnster]

How did you break the motor? 12 cells on a 5700 is way too high of RPMs, over 75K! You shouldn't go over 9-10 cells max w/ the 5700.

Really those speeds are pretty poor, sounds like the truck is way undergeared as well. I can easily do mid 40s on 7 GP3300 cells on a 380C/6L (5800 kv,) so 12 cells should be into the 60s (before it blows up.) What gearing are you using?

[skellyo]

Originally Posted by Finnster

Really those speeds are pretty poor, sounds like the truck is way undergeared as well. I can easily do mid 40s on 7 GP3300 cells on a 380C/6L (5800 kv,) so 12 cells should be into the 60s (before it blows up.) What gearing are you using?

Yep, I'm with ya there. My T3 with 2S lipo on a 380C 6L has been GPS'ed at 47.7mph. Also, the 380C 6L is 4817kv, not 5800kv. http://img.diytrade.com/cdimg/85838/...1082222991.jpg

[Finnster]

Originally Posted by skellyo

Yep, I'm with ya there. My T3 with 2S lipo on a 380C 6L has been GPS'ed at 47.7mph. Also, the 380C 6L is 4817kv, not 5800kv. http://img.diytrade.com/cdimg/85838/...1082222991.jpg

Hmm, is this loaded then? I could have swore it was rated @ 5800, tho I bought it quite a while back, so maybe I'm misrecalling it...

Regardless, the above setup is def off. The Esc is rated for 3S lipo/ 12 cells, but the actual motor max depends on its kv (rpms/V) rating. The 5700 is ...5700 rpms/V. 12 cells is 14.4V, so that is well above the 65K rpm limit of the mamba motors. If you want to run that many cells you buy a lower kv motor like the 4600.)