View Single Post
Old
  (#17)
Cheater
Guest
 
Posts: n/a
12.07.2006, 01:07 AM

I am not saying this will work ,but I'm sure it is not that far of. Novak makes oversize speedos so that resistence is extremely low for that little edge in spec racing classes. Not many 10th scale batts I know of can support 700amps for any length of time. Most of novaks stuff is for 6 round cells, higher voltage setups only reguire a fraction of the amps.

ignoring eficiancey and other small variables brushless motors tend to follow some basic rules.

- more kv = less in.oz./amp torque (per amp)
- more kv in same size motor can handle more amps
- motors reach max eficiency at a voltage that puts them near there rpm limit
- smaller diameter motors can handle more rpm
- small motors and large motors make equal torque per amp if the kv are equal, however the larger motors tend to handle more amps


my MM 5700 makes aprox. .24 in.oz. of torque per amp I average less than 34 amp racing.

the 2700 kv small motor makes .5 in.oz./amp. So less than half the amps are required to make the same amount of torque

I would be running the 2700 on 2.5 times the voltage (6-cell nimh to 5 cell lipo). so the 2700 would be spinning the same rpm as a 6750 rpm motor on 2s = I can gear down a couple more teeth = even less amps required

new systeme would make the car weigh 20% less = 20% less amps needed.

I know this is pushing the limits, gearing for a particular track will be critical, and maybe not even worth it, but it is not that far off. Any constructive criticism is welcome, I am asking for it. Eagle tree graphs of hot 18TH scale cars or race condition 10th scales with a breif description of running conditions would be extremely usefull. Serums #'s for his monster are appriciated; there is a huge difference between the weight of it and my little car, but still worth considering. Shooting me down because Novak rated a speedo at 700 amps is not very constructive.
   
Reply With Quote