Motor types and ESC

[Darknight99]

Would someone mind educating me on Brushless/Brushed motors. The last time I delt with eletric motors it was all about the brushes and the turns. The ratings seem to have changed now and the amount of stress put on them seems to make a difference.


As an example why would I chose or not choose this motor http://www.castlecreations.com/en/m...tle-1410-1y-sensored-motor-3800kv-060-0065-00

Over say this motor http://www.castlecreations.com/en/m...-scale/1512-1800kv-sensored-motor-060-0062-00

How do you pick a proper ESC to go with these.

I tried to watch a few videos on this topic and while it did make sense. i was still left confused on whether or not a higher or lower kv was better.

For the purpose of the topic I'd be replacing the Outcast stock motor or a traxxas Revo 2.0 motor.

 

[digitaldude80]

Why do you want to replace the stock motor?

I see you selected the sensored motors. If you choose those, you'll have to replace the esc. If you choose sensorless motor you can keep using the stock esc.

 

[Darknight99]

I'm asking for the purpose of learning and understanding. The motors I picked were merely based on a first glance view. From what little I understand sensored motors can be controlled a bit more. The overall purpose of this post was to help me understand what I was looking at when viewing online.

 

[chevys10zr2003]

Why do you want to replace the stock motor?

I see you selected the sensored motors. If you choose those, you'll have to replace the esc. If you choose sensorless motor you can keep using the stock esc.

I believe that almost all of Castle's motors are now sensored, but their sensored motors can be ran sensored or sensorless so it doesn't matter if you get a sensored motor and a sensorless ESC. You just won't be able to run it as a sensored setup.

 

[Toiletpimp]

Btw. To answer your question... a higher kv rating usually pertains to more speed and less torque. Lower kv is normally used for heavier big trucks. They have better power and don't heat up as much, also not as fast. Gearing also makes a big difference.

 

[Darknight99]

Btw. To answer your question... a higher kv rating usually pertains to more speed and less torque. Lower kv is normally used for heavier big trucks. They have better power and don't heat up as much, also not as fast. Gearing also makes a big difference.

Got it. So the stock motors that come with these are a good balance? Esc and batteries would really be to make these things bullets? What sparked the interest is the fact there is a guy with Kraton that sounds like a jet when it passes by.

 

[Toiletpimp]

The reason for the "jet" like sound in these machines is simple... 6s plus metal to metal gears make these things sound ridiculous. 4s makes gear noise but when you stick 6s in them they scream like a pissed off badger! My Typhon sounds awesome on 6s.

#RAD

 

[Iamtheoutcast]

The reason for the "jet" like sound in these machines is simple... 6s plus metal to metal gears make these things sound ridiculous. 4s makes gear noise but when you stick 6s in them they scream like a pissed off badger! My Typhon sounds awesome on 6s.

I love the way my typhon on 6s deff screams but sounds great.

#RAD

 

[beefy nugz]

I'm fairly new to this stuff as well. I just got done converting a smaller scale brushed rc to brushless and have learned a little. The size of the can will also very the kv rating. For instance, a mini brushless motor like, the one i installed on a 1/18 is a 4800kv. This is more of a low end tourque/off road setup, while 7000+ kv would be for speed runs on road. Thats using a 2435 can. Which is 24mm x 35mm. These little guys really have to spin to create power. Then u have the blx in the outcast. I believe is a 4074. Much bigger can, much more torque. 2050 kv is right where it should be for off road use with this size motor. Drop same motor down to around 1000 kv, and that would be for crawling.

Jump up to 1/5 scale, 4885 size can with 1275kv. This is What comes in the traxxas xmaxx. And it' certainly not a crawler, it will do 50mph out of the box. But it' got a huge spur and pinion attached!

Maybe this helps to simplify, maybe not.

 

[Raji]

I'm fairly new to this stuff as well. I just got done converting a smaller scale brushed rc to brushless and have learned a little. The size of the can will also very the kv rating. For instance, a mini brushless motor like, the one i installed on a 1/18 is a 4800kv. This is more of a low end tourque/off road setup, while 7000+ kv would be for speed runs on road. Thats using a 2435 can. Which is 24mm x 35mm. These little guys really have to spin to create power. Then u have the blx in the outcast. I believe is a 4074. Much bigger can, much more torque. 2050 kv is right where it should be for off road use with this size motor. Drop same motor down to around 1000 kv, and that would be for crawling.

Jump up to 1/5 scale, 4885 size can with 1275kv. This is What comes in the traxxas xmaxx. And it' certainly not a crawler, it will do 50mph out of the box. But it' got a huge spur and pinion attached!

Maybe this helps to simplify, maybe not.

The KV is the number of cycles/minute.
High KV faster but less torque and vice a versa.

 

[Pickles]

The above 2 points kinda miss the point of KV, they are correct in saying a higher number equals more top speed and a lower number means more torque. However KV actually refers to Rpm per Volt. So the Lipo you are using makes a huge difference. Can size has no bearing on KV as suggested above, generally smaller motors are available in a higher KV as its expected that they will be run on lower voltage. Unless you're looking at crawler motors you won't find a 1,600kv motor for a micro as you would never fit a 6s lipo in it! It's not that it couldn't be produced it's just that there is no market for it. (I'm sure there's one or two, there's always an exception). Generally if you're planning on running 6s I'd probably go 1,650ish KV and 2,000 / 2,2000kv for 4s motor can size also makes a difference generally the bigger the can the more torque you'll get as it can generate a stronger magnetic force. So it's possible for a 2,000kv motor to generate more torque than a 1,600kv motor if its a much bigger can. You can also gear motors up and down obviously. The other thing to consider is heat, the higher the KV the hoter a motor will run (gearing depending) and the bigger the can the higher you will be able to gear it without it over heating.

 

[beefy nugz]

Different can sizes offer different kv ratings is what I was pointing out.

 

[Typhon]

Nicely wrote Pickles. Stock motor and esc are plenty adaptive. In the talion and typhon the gearing is very conservative and im sure many other arrma vehicles are as well. Ive upped to a 17t pinion in my typhon on 4s and my temps never exceed 130 degrees. Still has plenty of torque and probably a solid 5-7 mph increase. Key pointers i can give is to buy a quality battery with a higher discharge rate. I find my motor runs cooler and has more power on demand. As for sensored and sensorless not sure if anyone touched this topic for you. I wont be the best to explain it and will probably need a better interpretation of it. At the track when you come to a stop you'll have a slight pause before you take off as the esc and motor have to "find" a so called starting position. Sensored escs/motors are in constant communication with each other which results in smoother/faster response. No stutter. I was told sensored setups use slightly more battery but im sure thats minimal.

 

[Zeus]

GREAT QUESTION...I think Arrma is pretty close with their combos...so upgrading their stuff stumps me a bit too.
I.e everything gets really hot...lipo, motor,
esc.

GENERALLY (AS ALWAYS)
Sensored setup and high kv ideal for crawling. But NOT GOOD for bashing. More circuitry = more complexity, more frailty and also the circuitry does NOT like the water. Even the crawler crowd sometimes avoid sensored - they go very high kv which eliminates worst of the cogging.

And Generally...with other brands anyway.
Esc is ALWAYS first thing to upgrade because you cant really upgrade anything else first.
By itself it will punch out heaps more C - as long as the batteries are up to it.

Esc IS the heart. A bigger speed controller is not going to hurt anything except for the size/weight penalty...your motor not blow up with a bigger esc!

As for motors do them last. A bigger can size is more powerful but also heavier.
The Kv (Speed volt ratio) is more a tuning choice.
High kv = Athletic high speed muscles.
Low kv = Body builder, slower but hugely strong.
Generally most go @1/3 lower kv than stock and then use the extra strength to gear up.
Increases speed while keeping motor revs and temps down.

Cogging is normal, some days it seems worse than others. But ignore it. After a while you wont notice it ... if you still do, youre not bashing often enough bro!