Hey Folks,

Yes I have been doing some reading and trying to better understand the world of digital esc's and motors brush / brushless..

I am fairly new to the NEW style of electric RC cars. I used to have the old school speed controls running off servos and sliding contact points...

Anyhow, I guess now there is not quite a direct correlation between brush and brushless but they are referenced in a closeness group, ie: 27t/17.5

I know the 27turns, but what does 17.5 relate to? The Kv?
The cans are about the same , 500 - 550 cans but the brushless puts out a stronger direct power with esc..? Now what does the 45A, 60A rating do for the esc when controlling the motor?

Lastly, I use a new 5000mah 20c 2s 7.4V Lipo. Why do I see different sized lipos like 50c, 45c, 70c , etc.. I have read a little on them and from what I surmise, the larger "c" rating the more juice can feed your motor by way of your esc..??

I really appreciate all you help out there from you "GURUS".. LOL!

Am I on the right track?

17.5 used to mean the motor was close to a 17.5 turn brushed motor or something like that. I don't think that # even means much of anything anymore.

17.5=slow and built to ROAR stock specs.
8.5=medium
4.5=fast

Really nothing more to it than that. If you choose a mototr too fast, your gearing won't make any sense and the car may overheat and be a pain to drive.

Just visit your local track or post here what you're planning to run, for motor advice.

The battery spec are mostly baloney. Not as poor as servo specs but close. The higher C rating is a battery that can output more amps. 30 is plenty. 20 is fine for 1/10th scale offroad. I'd try for the lightest battery. 4000mah, 25c is plenty for 1/10th 2wd.

A 50c battery that is 5000mah....
50x5=250 amps. That's alot of amps. I really don't think these little batteries can meet thier spec reliably for long.

It's more likely that the marketing department determines C rating, not whoever load tests the batteries. I have a pair of Orion socks rated at 60c.

I'll leave the motor explanation to someone else; doesn't really make any sense to me, either.

The amperage (A) rating is the throughput of your ESC or the max current draw of the motor, depending on which spec you're looking at. As ever, more is better Best to have an ESC with a higher throughput rating than the motor, as the motor can't physically draw too much unless you've got your gearing wrong or a mechanical issue.

The C rating applies to batteries, and is a half-arsed way of specifying the maximum current that the battery can supply as a function of it's capacity in miliamp-hours (mAh). The 'C' actually stands for capacity. A 20C 5000 mAh battery supposedly can supply 100A of current (20C*5000 mA=100A). In general, higher is better (more burst=more torque, effectively) but you need to know going in that there's no standardized way of measuring C and some companies will try to snow you with massively inflated claims.

IMO, your best bet is to buy the best batteries you can afford from known good suppliers (search- tons of reading on this topic including who to avoid) and also to splash for a good charger (separate subject; search on this as well). These products are at the foundation of your enjoyment of the hobby and IMO it makes no sense to skimp here. For what it's worth, I have an iCharger 208 and batteries by Gens Ace and ValueHobby (G-Force). They're good. Maybe not the best, definitely not the worst, not the cheapest, and not the most expensive.

$0.02

Well I will try to clear some of this up. Just some....
As far as bl motors go just as the #s meant in brushed motors it relates to the ammount of raps around each pole of stator. Like a 17.5 t has 17½ coils of wire around each pole. Now unlike old brushed motors the stock 27t was a single wire but the new bl novak17.5 actually uses 2 wires together . And I'm sure (or guess) other 17.5 motors r the same. Now the 3.0-3.5t bl motors have 3½ raps but with like 3-5 wires... but some manufactures don't rate their motors in turns . So u will have to find a way to convert kv ratings to turn ratings. As far a 440 motors vs 550 motors I am guessing this is some type of displacement #?? The 550 motors r same inside but have longer statorsand magnets for added tq . Fyi a 550 4.5t is nothing like a 440/4.5t the 550 has 3-4x more tq with about ½ the rpm

What Orion ESC would work great on my sc10 4x4? I have a 4.5 550 motor.Thanks Guys

Not sure about the Orion brand. Why not a novak havoc pro sc? With xdrive. Great speedo for the money I feel

Hey fellow old timer, welcome back!

As mentioned 17.5 brushless is the new 1/10 scale stock, and does indeed mean the number of wire winds, not unlike the good ol’ brushed days. (the numbers are different though)

Something to be aware of for stock is “boosted” speed controls, they add dynamic timing advance per RPM to greatly increase the top end of a “stock” motor (ramping, turbo, supercharged are some of the other terms and tricks).

ROAR and many races/tracks now run “blinky” stock, not allowing any of the ESC tricks. Blinky refers to a documented blinking light to indicate the no timing advance mode for teching purposes. But some tracks still allow boost, sometimes called open 17.5, probably some other terms out there.

For modified, well we have virtually unlimited power nowadays. Many (most?) mortal drivers will do best with around a 10.5 for 2wd offroad mod. The truly big boys are usually around 7.5 to 8.5 at most for mod buggy, maybe down to 6.5 for trucks, perhaps 5.5 for 4 wheel drive buggies.

All of this is for sensored systems, involves a standard connector with small wires between motor and ESC, so the ESC knows where the motor is. Almost standard for the traditional 1/10 racing classes. Oh, the standard 1/10 motor size is called 540.



The motors rated by kV (RPM per volt), are generally not sensored. Very popular for non racing, called bashing these days. And are used by some for the newer and larger RC classes like 1/8 scale buggies and 4x4 short course trucks. Non sensored deals typically don’t work well with stock level motors, can have low speed cogging and inconsistent starting. But with hotter motors they don’t have as much issues. Personally for racing I’d stick with sensored, but hey, others will disagree, and that’s OK.

Whew, enough rambling for now. If you like I can go over lipo ratings, myths and realities, next time.

Again welcome back! The new tech is great and actually much easier once you get the hang of it.

Hey Guys,

Well thanks for all the help and great information.. Recently I have been doing some reading and along with your posts have found some great technical information that has answered lots of questions rattling around in my head. Lipo Tech Read

Dave, Great to know the 540 can is the 1/10 stock! Recently I have decided to keep my SC in the stock class to compete, yes I am a racer at heart..

Now guys, I just picked up a used CASTLE CREATIONS SIDEWINDER SV2 AND 4 POLE 1406 4600 KV MOTOR from elh4564 in this forum. (would this be a mod class? The CC site lists this setup maxxing at a 3s lipo, can i use my 2s lipo? My understanding is that it will use the 2s lipo power I feed it and not max or burn it out because it falls under the max threshold 3s 12.6v? )

I have also just purchased two 5000mah 35C 2s lipos, which from my new understanding is moderate and keep me out of trouble and in the running....

My current T4.1 has a HW ezrun s10 RTR esc and a brushless HW motor with no specs but looks like a 540 size. Athough I think its a 3650kV per ezrun pdf by HW. From what I see it is the combo package type and does not get very hot, just moderate, with a new 5000mah 20c 2s lipo...

I am still researching ESC's and motors, seems like a never ending quest... (60A sensored is my current thesis)

Again thanks for the welcome back!!

--OldGuydust to see you soon.. poof!

For anyone looking to size motors or ESCs from a little different angle (based on rough size and speed desired) have a look at my post on my blog. If you search for steventaitinger how to choose rc car esc you should find it.

Holy thread bump!

You might want to read the current ROAR rule book to understand what is legal for racing, if you want to compete. They have technical specifications on the motors (2 pole), batteries (2s) and ESC's (blinking in stock). That 4pole motor won't be legal in sanctioned events, though for your first race they will let you run what you have in novice class. If you are going to buy something specifically to race, you probably want to make sure it is legal.

Just had a failure in my new Redcat KT12's esc reciver combo. Wanting to upgrade the drivetrain and don't know what motor esc reciever combo to get. Would like to go brushless if not too expensive. May need to stick with brushed. Would like to spend around $100-$200, less if possible. Would be good if it was faster as well, so long as i can keep decent torq. Let me know what you think. Is a 1/12 truggy 4x4. Thanks for all the help!