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Discussion Starter · #1 ·
Hey guys ive been PM-ing zoomer all types of questions and getting excellent responses but i figured id post up some questions i have cos i know there are other people like me(NITRO people) that will want this information too.
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OK, basically im trying to choose an esc for a M03 mini so heres my questions.


What effect does:


-PWM frequency


-Motor turn limit(what is a realistic turn limit im likely to use?)


-On resistance (obviously lower resistance is better but will i notice it)


Have on the performance of the esc?


Cheers
 

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ESC Basics 101, here goes...


husky said:
What effect does:


-PWM frequency

Lower freq gives more "punch", higher freq is smoother & more efficient.


Lately Novak thinks even pro racers won't use higher than 11kHz with their new GTX, but the current GT7 can do 22kHz.


At the low end the usual is about 2kHz.


15 yrs ago everything was 60Hz.


-Motor turn limit(what is a realistic turn limit im likely to use?)

Stock and 540 motors are 27 turn.


Japan stock is 23 turn, USA runs 19 turn classes too.


Mod - anything goes. The fast boys are running 7/8/9/10 turns, Europe has a 12-turn mod limit.


In a FWD Mini, anything more than a SportTuned (consider ita warm 27turn) doesn't improve lap times anyway.


-On resistance (obviously lower resistance is better but will i notice it)

Motor limit = max continuous current & is a factor of ESC's resistance.


More expensive ESCs use better FETs or more of them in parallel, so resistance is lower.


Less resistance means the FETs run cooler when fully worked, when running 'hot' motors. With a 540, any decent ESC would be stone cold.


Nope, won't notice it on a M03.
 

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for the average club/backyard hack (that means me) the only thing you reall need to worry about is the size of the esc and the motor limit.


general rule with motors is less turns the faster you go. if a speedie is rated at 13t limit then that means it can't handle motors with less than 13 turns
 

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btw read the fine print. FET ratings are done "at 25 degC" industry standard.


Trouble is... pass current thru any FET and it'll warm up (resistance, remember?). Warm FETs increase their resistance... Catch 22.
 

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Discussion Starter · #5 ·
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is wire gague important? some are 16 some are 14?????


also do you buy a specific turn motor or do people wint their own?</TD></TR>
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<BLOCKQUOTE id=1ce7e581></BLOCKQUOTE></BLOCKQUOTE>Edited by: husky
 

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Discussion Starter · #6 ·
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<TD id=HB_Focus_Element vAlign=top width="100%" background="" height=250 UNABLE="off">Ive also seen some esc with traction control and abs! are these worth having? </TD></TR>
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With stock motors if you didn't no this about every 5 full batery runs you need to get them like restrung or something by the lhs. Where as with the 540 can motors you can run them as many batteries as you like.
 

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is wire gague important? some are 16 some are 14?????

The lower the number the less resistence, lowest I've seen is 12, also really flexible.


also do you buy a specific turn motor or do people wint their own?

You buy specific turns, although if you want anything under 5 turns you'll have to unwind the armature. But you'll have to see if yourESC can handle theextra amps. Also thereis only one 20T motor I know of... the Traxxas Stinger, then haven't heard of any 22,24,25,26 turns then anythingfrom 28 to 35they also don't make. Then higher turns except 36 are mainly for micros.



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Ive also seen some esc with traction control and abs! are these worth having?

It is useful for offroad racing so you don't slip on the loose dirt, could be useful in on road racing as well, I don't think as much though. Also some transmitters have the ABS feature as well like the Futaba 2PL.


With stock motors if you didn't no this about every 5 full batery runs you need to get them like restrung or something by the lhs. Where as with the 540 can motors you can run them as many batteries as you like.
Yeah, that's only right if your really into racing. The commuator (comm - gold shiny bit on the arm)on the armature (arm - thingy in the motor that spins around)gets worn so you need it to get cut so it's back to it's normal shiny gold. You can also do this to 540 motors but you need a special lathe (comm cutter). although I don't think it's worth it because to get it cut costs about $5-10 and a new motor is about $15. Also lathes aren't cheap either.</TD></TR></T></T></T></TABLE>


</TD></TR></T></T></T></TABLE>Edited by: finny
 

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Discussion Starter · #9 ·

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Discussion Starter · #10 ·
Also the novak is rated at 40Amps but the futaba is 200Amps. What does this affect?
 

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Discussion Starter · #11 ·
any one have experiance with the novak fusion? Its only $10 more than the XRS and can be sh*tched to 7.8KHz and is rated at 24o Amps. Sorry for all the qns but my only electric(stadium blitzer) had a mechanical speed control.
 

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Fusion is pretty old tech, from the chunkier heavy era.
They work.





husky said:
Also the novak is rated at 40Amps but the futaba is 200Amps. What does this affect?

Don't ask me why, but supposedly Novak has decided to revise the way they rate the max current on their ESCs.


The upcoming GTX is labelled at "160A", which looks really stupid when they bung it on the same spec chart next to the GT7 which has "640A".





Whereabouts are you getting the XRS from?


Its definitely superior to the Futaba 230 for sure.


Might piggyback and get an XRS too, hehe...
 

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Discussion Starter · #13 ·
I think i will be getting the XRS from tower hobbies at $50US it sounds alright. The other option i was looking at was the Futaba 330 at $70US but when i found that $30 Futaba i figured i would be better off with the XRS. Do you really want an XRS? I can always add another to the order
. Dont you have a super dooper novak esc? The GT7??


I just liked the fact that with the fusion you can switch the frequency way above the 1000HZ the Xrs does, but it is alot bigger unit
 

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Tower ain't too cheap after you consider postage & handling... think both XRS and Futaba 330 both sell for roughly the same price in US?





Heh... yeah, I "collect" orange goods - love 'em.
Bought1st GT7 about 2 wks ago (merely as a learning exercise), its still sitting in the spares box. Haven't had a need to stick it into anything yet, as most of my cars are already running Cyclones anyway... and everyone admits ancient Cyclones are better than GT7s anyway hehe.


Novak USA's customer service is the best, bar none.
 

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I'm glad Husky is asking these Q's on the forum as it lets us all learn a bit as well.



But I gotta say it's like ya'll are speaking a foreign language.
 

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Skidd said:
But I gotta say it's like ya'll are speaking a foreign language.

Ahh, its all common sense really.


ESC controls power to the motor by pulsing its MOSFET (metal-oxide semiconductor field effect transistor = switch).


If your RX is feeding out a throttle signal of 60%, the transistors will be 'on' for 60% of the time, 'off' for 40%.


The frequency of the switching eg 60Hz is how often the FETs switch... ie each cycle is 1/60th of a second.


Transistors all have some resistance (impediment to current flow) in them, just like a light bulb filament. Resistance causes heat when you pass current through them. Too much heat and it blows up.


High school physics... you can halve resistance by doubling up FETs in parallel. Modern power FETs are capable of about 50-80A each... so they use multiples in parallel.


Peak (momentary) vs continuous (ongoing) max current is another issue. Some ESCs quote silly huge currents but they can only handle that for very short times.


What motor limit the ESC factory labels it with is also arbitrary, there's no 1 formula. Usually the engineers would try to be conservative, but then they get bashed on the noggin' by the marketing girls who want a "bigger is better" spec to print.
 

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The only bit of that I understood was "bigger is better"



I guess I'll have to get some background in all this if I'm going to get Amy an electric MT.
 

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Skidd said:
The only bit of that I understood was "bigger is better"

Always holds true, matey... especially when talking about HAMMERs.


I guess I'll have to get some background in all this if I'm going to get Amy an electric MT.

I'm getting a tad tempted at a TLT-1 (Tamiya Little Truck series).


Its a "1/18th scale monster"... in real life it's about 15" long. 4WD with 4-link suspension, you can run std electronics and 540 motor in it. (yep 540 in a "1/18th").


You want one too?
 
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