How to determine or know an ESC AMP capacity?

parcou

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I could be asking this question wrong. I do not know the science behind and ESC power and how that is used. I hear terms like AMP and voltage and BEC not sure how all that works. Any videos or docs to explain?

This is what I am I have Firma 130A ESC. I want to put two of radio-controlled RC 8.4v fans (motor & ESC). I have done this on the larger Max6, Firma 160A since they were large ESC never thought about the if they would have enough power....so far no isses.

The ESC will have the Firma 130A ESC
Continuous Maximum Current: 130A (760A Max Burst)
Input Voltage: 7.4 - 14.8V
BEC Voltage: 6V (4A)

Servo 6V DS3235
Operating speed (at no load): 0.12 sec/60 degree @6.0V
Stall torque (at locked): 32kg/cm @6.0V

Lights (front bumper, rear bumper, roof) roof would a led lights on the front/rear of the roof

Fans (2x)
Run on receiver voltage (5 to 8.4 volts)
Deliver 28cfm @ 8 volts
1.55 amp


How do I understand the science of ESC to know if 2 of those fans will work with this ESC?

Thx
 

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An aftermarket bec can supply more voltage and as importantly more amperage. Many high end servos require high amperage as well as 7.4v or sometimes more.

you can use the stock esc to power the fans, and use the external bec to supply the higher voltage and amperage to the servo.

single voltages. You can split the output to many devices as long as the current doesn't exceed the capability of the BEC. Use a simple y-splitter or DIY your cables.

But it will cut out. If you run close to it.
Best bet is a castle external bec. I have one brand new if needed.


Here’s a link

https://www.rcdriver.com/where-does-all-the-power-go/
 

nomis38

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You will be fine running those two fans and servo on that esc's BEC. FYI BEC's are a seperate component, even ones that are built into the ESC, They do not share load or voltage with the ESC itself.

If overloaded the BEC can cause a brownout or reboot of your system. But again you aren't overloading it.
 

RedOctobyr

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BEC Voltage: 6V (4A)
Servo 6V DS3235

Lights (front bumper, rear bumper, roof) roof would a led lights on the front/rear of the roof

Fans (2x)
Deliver 28cfm @ 8 volts
1.55 amp

Best bet is a castle external bec. I have one brand new if needed.

Can I ask which Castle BEC, and what you're asking for it? You can message me, if that's preferable. I'm considering a servo upgrade, and/or adding a modest BEC, preferably with the ability to do 8.4V. Maybe getting a bit more performance out of a moderately-priced servo upgrade, or from my stock servo (at 6V, but can take 7.4).

You will be fine running those two fans and servo on that esc's BEC. FYI BEC's are a seperate component, even ones that are built into the ESC, They do not share load or voltage with the ESC itself.

If overloaded the BEC can cause a brownout or reboot of your system. But again you aren't overloading it.

I haven't used the ESC, and maybe its ratings are super-conservative. But the stall torque for the servo is probably around 2A (found a reference here: https://aeproductsourcesite.alicdn....eI.zip&token=33194c3d02ce6e3ee6e2fef6f322aa0a)

Then there's lights. And 2 fans, which each draw 1.55A, presumably at 8V (like the CFM rating). Scaling down to 6V, that would suggest 1.2A each, at 6V, so 2.4A (out of the 4A rating) constantly going to fans. Then the servo (max 2A), plus unknown draw by the lights.

I guess to me it seems somewhat less clear-cut that the integrated BEC wouldn't be overloaded, especially not know what the lights use?
 

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An aftermarket bec can supply more voltage and as importantly more amperage. Many high end servos require high amperage as well as 7.4v or sometimes more.

you can use the stock esc to power the fans, and use the external bec to supply the higher voltage and amperage to the servo.

single voltages. You can split the output to many devices as long as the current doesn't exceed the capability of the BEC. Use a simple y-splitter or DIY your cables.

But it will cut out. If you run close to it.
Best bet is a castle external bec. I have one brand new if needed.


Here’s a link

https://www.rcdriver.com/where-does-all-the-power-go/

Castle Creations 10 Amp Adjustable BEC​

Brand new in the bag still. Reason why I bought for some 4S fans that I was making. Ended up not needing either. If you are interested just PM me and once I get home I’ll take some photos
 

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Ok clear cut lol. Then i'll follow up with experience and pictures so you know you can trust my words lol. So constant amps, and peak amps are different. The burst of your internal bec isn't 3 or 4amps, it's prolly more like 8 or 10. Trust me a 6v servo - that will not be pulling 2amps, and two fans, and some lights will not need a external BEC. Ask me how I know lololol. (below)

All these heli's are $3000 plus 700 heli's, Heli's run 4 servos and a receiver. If I get a brown out, it falls out of the air, and I lose a lot of money, So trust me I understand how, why, and when to use a external BEC. If you get a brown out its not a big deal as your model doesn't drop from 100ft and hit the ground. I have never seen anyone with 2 fans, even the super high rpm ones, some lights, and a 6v servo need an external BEC. it'll be wasted money. And the castle ones cost what a new servo costs. On heli's most times the internal BEC is enough even for 4 servos and other crap.

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Awesome, those are beautiful! What does the 3-bladed head offer? I've never used anything besides 2 blades. Does it fly better?

My "big" heli (which is small by comparison) is a Gaui X5, more like 500-class. I have a Castle BEC Pro on it, because I wasn't comfortable using the Phoenix 100's 5A built-in BEC. Then, because I'm a chicken (and have had a bit of experience with power problems on my 450), I also added a Scorpion Backup Guard (has an integrated, small 2S LiPo). So if the BEC voltage ever drops below 5V, this instantly kicks in to maintain it, so you don't brow-out and crash.

When I bought it (used, but looking new), I hadn't flown it, but was going through it on the bench. And one of the XT60 (?) connectors installed by the previous owner simply came off, while I was messing with wiring. I changed the connectors to my choice anyhow, but that spooked me a bit, about a very-expensive (for me, though not like a 700!) power loss.

I'm less worried about power-loss now, getting back into ground RC. Seems like (with electric), if you lose BEC power, you probably roll to a stop. You might roll into something, but it's probably not an instant death sentence, at least. Not like on a heli.
 

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Awesome, those are beautiful! What does the 3-bladed head offer? I've never used anything besides 2 blades. Does it fly better?

My "big" heli (which is small by comparison) is a Gaui X5, more like 500-class. I have a Castle BEC Pro on it, because I wasn't comfortable using the Phoenix 100's 5A built-in BEC. Then, because I'm a chicken (and have had a bit of experience with power problems on my 450), I also added a Scorpion Backup Guard (has an integrated, small 2S LiPo). So if the BEC voltage ever drops below 5V, this instantly kicks in to maintain it, so you don't brow-out and crash.

When I bought it (used, but looking new), I hadn't flown it, but was going through it on the bench. And one of the XT60 (?) connectors installed by the previous owner simply came off, while I was messing with wiring. I changed the connectors to my choice anyhow, but that spooked me a bit, about a very-expensive (for me, though not like a 700!) power loss.

I'm less worried about power-loss now, getting back into ground RC. Seems like (with electric), if you lose BEC power, you probably roll to a stop. You might roll into something, but it's probably not an instant death sentence, at least. Not like on a heli.
The three bladed head offers much more instant torque and so much more surface area, its night and day more stable then a two blade.

Never used a Scorpion backup guard, thats cool. I just run straight 2s lipo to my flight controllers on some. The Diabolo and Triblade are just BEC, but those ESC's both have dual bec, so you plug two servo leads into the flight controller and it'll switch if one dies.

Hahaha correct if you lose power on land its not the end of the world like on a heli. Those are bad days lol when you see a brown out at the field on a heli.

A Gaui X5 is a great heli. Never had one but ive flown one and love the design. The one I just built is another that is a totally different and cool design the OXY 5 Meg, 500 class streched to 600.

320736373_675112777482129_3813455557295348699_n.jpg
 

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The three bladed head offers much more instant torque and so much more surface area, its night and day more stable then a two blade.

Never used a Scorpion backup guard, thats cool. I just run straight 2s lipo to my flight controllers on some. The Diabolo and Triblade are just BEC, but those ESC's both have dual bec, so you plug two servo leads into the flight controller and it'll switch if one dies.

Hahaha correct if you lose power on land its not the end of the world like on a heli. Those are bad days lol when you see a brown out at the field on a heli.

A Gaui X5 is a great heli. Never had one but ive flown one and love the design. The one I just built is another that is a totally different and cool design the OXY 5 Meg, 500 class streched to 600.
Very cool, thanks! Things have apparently continued evolving. The 3-blalded head sounds great! And dual integrated BECs, nice, I didn't even know that was a thing.

Sadly, I haven't flown my helis in 5+ years. But that video was fun to watch, and helps inspire getting them out again. Honestly, it's been long enough (and my less-intimidating stretched 450 is in a mangled heap, after a main blade broke during it's final flight) that I'm nervous about flying the X5 again. Those batteries are now being put to use in my new truck.

I've heard about Oxy helis, but don't know anything about them, unfortunately. The SAB machines I believe are typically all belt-driven, which sounds awesome. I've only had straight gears and torque tubes, which are noisy by comparison, with more vibration.
 

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Very cool, thanks! Things have apparently continued evolving. The 3-blalded head sounds great! And dual integrated BECs, nice, I didn't even know that was a thing.

Sadly, I haven't flown my helis in 5+ years. But that video was fun to watch, and helps inspire getting them out again. Honestly, it's been long enough (and my less-intimidating stretched 450 is in a mangled heap, after a main blade broke during it's final flight) that I'm nervous about flying the X5 again. Those batteries are now being put to use in my new truck.

I've heard about Oxy helis, but don't know anything about them, unfortunately. The SAB machines I believe are typically all belt-driven, which sounds awesome. I've only had straight gears and torque tubes, which are noisy by comparison, with more vibration.
Yeah I'll be honest the SAB's are the easiest to work on and least pain in the butt after a crash. I hope you do pull a heli out sometime soon, and hope its a fun experience. I've been doing them for so long I can build em in my sleep and rarely have an issue. 99.5% of my time is flying, when its 99% headache it get draining.

Maybe look into a flight controller with stability mode, or bailout, it helps get us over that hump of nervous flight.

Ive used them all, ikon, vbar, vbar neo, beast, spektrum 6250's, 3gx, and so on lol. By far and away the best IMO is Spirit Flybarless. And it has auto-leveling and bailout if needed.
 

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Thanks. I've used a VBar clone, and my X5 has an iKon, with self-leveling. That's a good point, I'd have that as insurance. I think I only had to use the "Oh crap!" switch once "in anger", thankfully. Other than that, it was only used for testing that it functioned properly.

Funny, I only recognize about half the names in your flight controller list :) I am way behind. Thanks for the tips!
 

nomis38

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Thanks. I've used a VBar clone, and my X5 has an iKon, with self-leveling. That's a good point, I'd have that as insurance. I think I only had to use the "Oh crap!" switch once "in anger", thankfully. Other than that, it was only used for testing that it functioned properly.

Funny, I only recognize about half the names in your flight controller list :) I am way behind. Thanks for the tips!
Naw ur not behind if you've used a "k-bar, knock off vBar" and have an iKon your good to go honestly. iKon is my other top choice. They are easy to setup and also have safety help features such as auto-leveling and bailout.
 
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