Question about runtime with a brushless motor.

[komugen]

I am a newbie to this forum, and I have a question. I have been driving 1/8 nitro buggy (not an expert, and not a racer), and I am trying to get into an electric buggy as well. 15 years ago, I had a electric off-road buggy, but the industry changed so much since then (ESCs, motors, batteries and even car itself are so much different than back then.) . I hope somebody can give me some idea about recent electric cars. I am trying to buy RC10B4 with the brushless motor configuration (either Novak system or new LRP sphere system). Can anybody tell me how fast are they (how many mph?)? Also, what will its runtime (in minutes) be (let's say I use a 3300mah or 3700 mah Ni-MH battery)? Since there is no LHS around my area (it's a bummer that the closest LHS is 5 hours away from my house by driving), I have nobody to ask this simple question. I need somebody's advise.

[tcolesen]

A RC10B4 with the appropriate gearing should get to about 40mph with the the Sphere/Neo, and 35mph with the Novak SS580. Runtime depends upon terrain and driving style, but about 10mins.

[komugen]

Thank you, tcolesen. It helps me a lot. I wish it would run more than 10 minutes. The run time is similar to 15 years ago (but the speed sounds amazing.). I am guessing the motor and ESC are a lot faster and more powerful than back then.

[Rtsbasic]

The kit would have a lot more acceleration than any setup you had "back in the day" :) Runtime for racing would be around 10 mins for either system, but for messing around/bashing runtime can be upto 30 mins. You can get slightly slower motors that give more runtime, for example my "Mtroniks plasma sport" motor with a Mtroniks genesis esc gives me about 15 mins racing time, and on 6 cells will still hit around 36-37mph with brilliant acceleration. Reason being its a small, light motor in a light car (TC3 with carbon fiber chassis). This is on matched GP3300 6 cell packs.

Realistically if your not racing with the Reedy/LRP system in a B4 by the numbers you'll probably get about 15 mins of runtime, pending on how hard your pushing it and what your doing. If your racing 10 mins is about right.

[bholio]

You'll get more runtime if you gear it down (within reason) to run at a slower top speed. I got almost 30 min runtime with the novak 5800 in a Tamiya Hornet on a crappy 3000 battery. And it was uncontrollably fast because the hornet is very lightweight.

Heres another thread talking about the novak in a B4
http://forums.radiocontrolzone.com/showthread.php?t=202291

[Mangokiwi]

Sphere/Neo one+GP3300, Stadium Truck, 14:1:1: 9 minutes.

[Gojira]

my buddys t4 runs for 15 min on 3800mah and a ten turn brushed motor

[komugen]

Thanks, everyone.
It is very interested in to know all of those tips and secrets. I didn't know gearing down would make any difference with the run time. In gas buggys (which I currently have), carbretor setting made changes in the runtime, but gearing up/down didn't affect the runtime (at least it doesn't make any noticable change in runtime). Since I live in Japan, it is difficult for me to get something other than Novak or LRP. Also, the other thread "bholio" suggested for me was very helpful, and thank you. I think I am going to order 10b4 with the Novak brushless system, two 3600mAh batteries and several gears. It should give me plenty of runtime and speed for me. I am excited to get my new hobby. By the way, another stupid question, why are more people still using brushed motors? No more heavy and expensive commutator, no more motor maintenance with plenty of runtime and speed. It sounds like a dream, but there should be some negative aspects.

[Mangokiwi]

Quote:
why are more people still using brushed motors? No more heavy and expensive commutator, no more motor maintenance with plenty of runtime and speed. It sounds like a dream, but there should be some negative aspects.

This technology is new to RC Car and some contollers still have teething troubles, like thermal issue, brake, compatibilities with other systems etc.
Some are simply too expensive.

[Rtsbasic]

People resist change..brushless motors normally have a very different "feel" to them when racing. Cars with brushless motors will coast a lot further so no drag brakes (although on a couple of controllers you can enable them to get the same effect, the LRP system is supposed to be good for this). Small things like this don't matter for the most part, its just a lot of people don't want to have to adjust to these things.

[komugen]

Quote:
Cars with brushless motors will coast a lot further so no drag brakes (although on a couple of controllers you can enable them to get the same effect, the LRP system is supposed to be good for this).

LRP sounds better now, but is it already available in the market? In the RC magazine (Japanese magazine), it said it is not in the market yet (maybe, Japanese market has some time lag). I also checked out the Team Associate's web site, and the LRP Sphere ESC seems to have better features than Novak (especially for braking setup). I also liked Reedy NeoOne brushless motor, but it didn't have any spur/pinion gear recommendation. Does anyone have any recommendation what spur/pinion gearing should I use for the NEO One motor with my future 10b4? Should I use different gearing between sportsman (limitation of 24,000RPM) mode and unlimited mode?

[Rtsbasic]

I've seen it listed as in stock at a couple of sites, and I've read accounts of a couple of people having an LRP Sphere/LRP Vector combo here in the UK and getting brilliant performance out of it (keeping pace with 8 wind brushed) so its out for sure, just not everywhere has it yet.

A top UK driver Chris Doughty has ran them over here, his said "once they become legal I will certainly run one." and is very impressed by the system. The Nosram version is also out here.