Brushless size power scale ?

[MarNaDaKi]

Hi all.

Just would like to know where, in power, is located the 540 size short motor in relation to the 400 (380 in reality) S, L and XL ? Is it between the S and L, between the L and XL or after the XL.

Also, I haven't been able to find a size schematic for the Basic series. I know that they have the reputation of being really torquey for their size compared to any other motor of similar size. But where, in term of torque, are they located in the above power scale ?

[Andrewg]

The Lehner Basic is pretty typical of most 05 sized ie 36mm dia brushless motors. It is not a torquey brushless the same sized Hacker and Lehner withthe same KV will make more torque. However these motors make huge torque compared to any 05 ferrite magnet motor.

The 540 motor - the brushed motor varies in output as brushless do.

The brushles manufactrurers started trying to get veryone to run 400 (27mm diam motors. IMO these are not torquey enough.

It is much easier to get a 36 mm diam brushless to outperform a top line car motor in speed acceleration and runtime. In palce of the standard size 540 modified use a Lehner Basic; Mega 22/20; Hacker B50-s or C50-S; Kontronik 500; Aveox 3624; Nemesis B50-S.

BUT - becareful - brushless motors have much less impedance and inductance than brushed motors. This means if something goes wrong or your setup is wrong and causes driveline drag they can pull huge amps and will pop cells and controllers before they hurt.

When selecting a brushless keep the resistance above 15 mohms with the rpm you want and you should be fine. And test it carefully as you learn the setup. RUn it first on the lowest level of timing advance and increase it once you have everything sorted.

[MarNaDaKi]

In fact, what I wanted to get at, is this;

I am transforming an HPI Nitro MT2 into electric. I know that Novak SS or any other SHORT 380 (400) would be slightly over-taxed in such a 4WD truck. I am also affraid that a 540 size (Lehner 1920, Hacker B50) would be overkill as they are really strong beast.

So I was looking for an in-between motor. That's why I thought about a Basic or a L or XL version of a C40 or any other variant.

[starluckrc]

The Basic and C40-xxL motors are similar in power. The 540 will be fine in the nitro MT as well.....more power than you need, but that's half the fun.

[MarNaDaKi]

The 540 will be fine in the nitro MT as well.....more power than you need, but that's half the fun.

:D Yeah it's what I thought, more power than I need with a 540. :cool: But why waste run time for power that I will not be using. :confused:

Why not go for your Feigao 38084xx XL version ? Wouldn't it be better ballanced between power and runtime.

[Andrewg]

MarNaDaki

You are missing a key point about electric motors.

In nitro bigger = more power and often less rpm.

In electric bigger doesnt mean more powerful. The batteries determine the power; the motor merely converts it to energy. How efficeinct the motor is and whether it makes torque is what is important.

For you vehicle something like a Hacker B50-8L will be good. If you want more efficeincy at less than 35 amps - thats a full throttle run of more than 7 minutes on 3300's go to a 10 or 9

Shorter can means more rpm but lower efficiency 2-3% less torque (usually about 1/3 less) and a narrower power band.

Worse a 400 (27mm Diam) motor has way less efficiency and torque - usually about 10% less efficeincy than a 36mm can - so you get more heat and less acceleration and lower power output. Just less drivable rather than easier to drive.

Pick your rpm/v - Hacker and Kontronic are best in 2 poles - they have the widest power bands. But Plettenberg Mega and other multiple motors are so drivable it isnt funny and the Megas are cheap and FAST!

[MarNaDaKi]

:eek:

Ok ok Andrewg, you have kicked my ***** bucket way enough now. :p

I'll go by your advice and go with a 540 XXLarge version. I'll probably go with a Feigao (Nemesis) since I want to buy from starluckrc. Because I have not yet determined the number of cells I am gonna be using, I can't tell the wind number I will choose. With the help of the theorical speed formula, I'm gonna shoot for a 37-42MPH.

[starluckrc]

Well.....that's now all true exactly. Bigger means the CAPABILITY of more power for sure. Running a big motor well below it's intended operating range will lead to poor efficiency as well. The 540-xxL can is just too much unnecessary weight to carry around. The 540-xxS is already overkill but manageable. The 8 turn is quite nice on 6 cells.

[Andrewg]

Starluck - you have worked out the efficiency of the motors you are talking about? Which rpm/v motor are we talking about? Which brand? What V's and amps and what eta did u come up with?


MarNaDaki
ok which cells are you using?
how many are you going to use?
what run time do you want?
do you have a minimum rpm/v?

I can give you the optimum motor if you let me know

[starluckrc]

Just making generalizations. I have the motor constants for my Feigao motors and can work numbers on them. I use the 540-8S on 6 cells in stadium truck applications and know it to work quite well. It will put it on it's roof.

[MarNaDaKi]

I should have received my MT2 by next week. I will then be able to see how many GP 3300 I can cram into the chassis, to help me decide on the motor.

[Popop]

Andrew, nice to meet you here
Your info is always good to read !
Do you have some other BL manufacturers to indicate to me ?

I know about the BMI company (Chili peppers) ... but they seem pretty familiar ... Anything else ?

Thanks