Question on ESCs: Help!
 

Hi everyone, I'm a bit curious as to ESCs.

anyone can tell me why there is such a thing as motor limit. eg 12-turn limit. is the reason the esc cannot handle lets say, 9 turn motors because of the amp draw of the motor is too high during low speed(or is it high speed?), or is it the ESC is unable to dissipate heat fast enough to handle the 9 turn motor at low speeds and thus burns out?

is there a way to calculate what esc can be used for a certain motor if i know the max amp load of the motor and the rated current of the ESC?

thx in advance!

just also like to ask, if the rated current of an esc is higher, does it mean it can support motor of lower turns?

How do you know the Max Current draw of your Motor??
The Pulse draw to get it spinning or Continous at loaded or unloaded??

most escs on the market alreadi have the motor limit stated,it's should of like a market standard,...eg the lrp quantum competition has a limit of 5 turns...
should b of no problem when u obey the instructions n keep within the limit...

um, can check rcca magazine, sometimes they got features on motor, like the nov edition i think got 1 on trinity speed gems

Re: Question on ESCs: Help!
 

To my knowledge, an esc's performance is normally determined by the type, grade and number of FETs used. If an esc's motor limit is only up to say 12 turns, it simply means tat the FETs cannot take the load of any motor lower than that of a 12 turn. =)

i see...so the motor limit is due to the FETs and not to the max current the ESC can take.

just 1 more question on thermal protection: does this mean that, if i use dual motors on a, lets say, top end esc with thermal protection like the LRP F1 pro or the ipc 7.1 which have no turn limit for 1 motor but don't specify 2 motors, and the esc cannot take it, the thermal protection will kick in and i don't conk off the esc. ie. so i simply try-try the dual motor config until the esc says..."STOP ITS TOO HOT!"

not all esc r built 2 take in more than 1 6 cells batt pack,u will have 2 check the esc's spec 1st.

Actually the FETs (type and qty) very much determine how much current it (ESC) can handle. The FETs are the 'muscles' of ESC; for how much load it can carry thru, the heart is the microcontroller chip which determines the heartbeat freq (not all esc can be programmed) punchy or smooth, 1khz-4khz....depends on ESC.

As for twin motor load, (not all motor comes with dyno tag) look for current it draws, combine both n should be lower than ESC current (amps) handling spec.
The easy way is take from ppl experience, copy them. Or your method of trial and error-but this would be costly...
all providing that you have the correct gearing.
hope this helps :D

as mentioned by ijnek, most esc cannot handle 2 x 6 cell packs... some esc like the super rooster is able to handle up to a 10 cell pack. if u put the 2 x 6 cell packs in parallel, it shouldn't be a problem but u are not increasing ur voltage (top speed), just your capacity (run time).

i'm not sure about this but i think not only the esc will be fried if u pump in too high a voltage, but also the reciever as well. cos the reciever is powered thru the esc. to achieve more cells without fried reciever, u can try powering the reciever seperately by a rx pack. to do this, u will have to remove the red wire from the esc to the reciever leaving only signal and ground. even by doing this, the number of cells will still be limited by the esc FET rating. this just insures the reciever.

I thought it is the FET that produce the output Freq .
The MircoProcessor Control the FET Switching (On and off).
Then there is a Amplifer to Amplify the current??

If large current but little FET,the FET gets hot, and burnt out. So More FET mean can support high current= higher end ESC???

correct, FET is the one that do the switching, pulse rate still determine by the controller.:)

hmm so if the combined total current of the 2 motors don't exceed the max limit of the ESC, then i'm likely to be in business, if not the ESC will have that auto-protection feature turned on rite? LRP users, tell me so...! i got a LRP F1 Bullet(the old one before F1 Pro)

if can confirm then i will go get a couple of 11 to 13 turn motors to play with...

temp for me is no problem, i can get custom made heatsinks and install fan if necessary.