Sunday, January 3, 2010

Brushed Vs Brushless Motors.

My head is spinning faster than these motors.

I don't understand. ?!?!?!?!?

Maybe I'll just stick to brushed. They are super cheap these days! Who cares about changing the brushes and maybe the whole engine when they cost $15 in Japan. Who bothers to cut the commutator? Not me anymore.

But New tech is good. so let's GO GO Brushless!

From what I can gather. I should just consider the new technology and forget trying to campare to what I have. Brushless have different RPM and torque and therefore need different gearing for similar performance. They also can be changed by a controller in terms of Torque @ specific RPM if you have sensored versions.

What does this mean for me?

I need a range of Pinion and Spur gears as well as the Motor and ESC which are already quite expensive.

1. New Motor.

Engine Turns.
   Lower Turn = Higher Top End/Less Torque

   Higher Turn = Lower Top End/More Torque
   This is basically irrellevant on its own because now the world adds kV as a measure also

Race classes.
   Stock (27 Turn Brushed) ---> (17.5T Brushless)
   19T Spec (19 Turn Brushed) ---> (10.5T or 13.5T Brushless)

   Unlimited (Any amount of turns)
  Who knows??

I found this juicy comparo chart that totally contradicts this..

Castle Creations CM36
brushless / brushed equivelent:

S7700 (7,700kV) = 6-turn
S6900 (6,900kV) = 8-turn
S5700 (5,700kV) = 10-turn
S4600 (4,600kV) = 16-turn

LRP Vector
brushless / brushed equivelent:
X-11 3.0 (11,400kV) = 3-turn
X-11 3.5 (9,800kV) = 3-turn
X-11 4.0 (8,600kV) = 4-turn
X-11 4.5 (7,800kV) = 5-turn
X-11 5.5 (8,100kV) = 7-turn
X-11 6.5 (6,900kV) = 9-turn
X-11 7.5 (5,900kV) = 11-turn
X-11 13.5 (3,350kV) = stock 27-turn

Novak SS/EX/Velociti
brushless / brushed equivelent:
3.5R (10,500kV) = 3-turn
4.5R (9,000kV) = 5-turn
5.5R (7,400kV) = 7-turn
6.5R (6,400kV) = 9-turn
7.5R (5,800kV) = 11-turn
8.5 / SS5800 (5,000kV) = 13-turn
10.5 / SS4300 (4,200kV) = 19-turn
13.5 (3,300kV) = stock 27-turn

Reedy Neo-One
brushless / brushed equivelent:
4-Star (7,400kV) = 7-turn
3-Star (6,400kV) = 9-turn
2-Star (5,800kV) = 11-turn
1-Star (5,000kV) = 13-turn

Yokomo Sensored Range 6600yen
Zero 6.5T (7400kV)
Zero 7.5T (6100kV)
Zero 8.5T (5600kV)
Zero 10.5T (4500kV)
Zero 13.5T (3500kV) = Stock
Zero 15.5T (3100 kV)

Why the confusion about what translates. Well thats because the RPM, TORQUE delivery and max power can be varied.

2. New Electronic Speed Controller.
(My reverse is not working anyway.)
Brushed -> Brussless ESCs are not compatible, so you need a new one. But
Some Brushless to Brushed ESCs are compatible. so if you want to go back you can just change engine. Maybe. These are usually the more expensive PRO models.

It also should be noted that unless you are a smooth driver, like me. You need to get used to being more controlled with trottle application.

An ESC's specification is the lowest number of turns that it can handle. So a 8.5T ESC can be used from 17.t to 8.5T brushless motors.

Because of all this custom specification in engine braking and accelleration and off throttle zone and reverse. It gets quite difficult for a beginner to work it all out.

So lets look at the Yokomo Brushless starter combo.
I'll probably end up with this Yokomo setup for Drift Meeting.

A Yokomo Zero 13.5T Brushless (stock 27T equivillant engine) and the BL-SP which is capable of an 8.5T brushless motor in the future.
It only has control over Max power setting, Brake and neutral range settings which is a good thing for a beginner at new tech.

3. New Gearing

According to this cobmo chart you should be able to work out new gear ratios.
I've highlighted stock settings for Drift Package.

Yokomo Brushless engines (as above)

Zero 6.5T (7400kV)
Zero 7.5T (6100kV)
Zero 8.5T (5600kV)
Zero 10.5T (4500kV)
Zero 13.5T (3500kV)
Zero 15.5T (3100 kV)

Motor 1/10Touring    1/10Off     2WD 1/10 Off    4WD Drift

6.5T         1:8.5            1:10.0             1:10.5              -
7.5T         1:8.0            1:9.5               1:10.0              -
8.5T         1:7.5            1:9.0               1:9.5                -
10.5T       1:7.0            1:8.5               1:9.0              1:6.5
13.5T       1:6.5            1:8.0               1:8.5            1:6.0
15.5T       1:6.0            1:7.5               1:8.0              1:5.5

So what pinion and spur is that? I need a calculator. Arrrgh!

Can I still use my Nicads. Yes. Maybe won't last long though.

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