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Help identifying ESC?

Hi everyone.

I bought a second hand electohub about 2 years ago as my first real multirotor. Hasn't flown for awhile, so in anticipation for a gimbal, I would like to rebuild some of the mistakes I made, just going through and re-soldering, and tidying everything up a bit. Big plans for this one, I'm thinking about using it beside a tricopter for some part time aerial photography work.


I cant remember what the ESC are they are either the F-20A or F-30A from RTFquads. But both look identical from the outside with their branding on them.
How can I tell them apart?




Hostage Taker of Quads
Staff member
F20A vs. F30A . . . yeah, you'll need to look under the heatsink. The only difference between those two were the FETs used. Otherwise, everything else was identical.

Also, the RTFQ versions used different FETs than the HK ones, so you're probably going to have to ID the chip itself to get the current capacity -- matching via photo probably won't get you what you need.
Thanks, I removed the heat shrink, and turns out they are M3006D.

Couldn't find any datasheets on it that would actually load, Either were for the wrong part or didn't want to load the pdf.

However I have found someone who took apart their Hk f-20 esc. Were in that too. I guess It's a 20A ESC

Just by looking on the RTF quads images, they use a 85A3 on their 20A
So perhaps this Is A re-branded 20A HK ESC, or an early version of the RTF quad ones.
So just a question about the build, wanting to make as clean as I can. These ESC are huge for a 20A, I've got some littlebee 20A sitting here not being used. I could get rid of these ESC and replace with the littlebees. That would allow me to mount the ESC inboard, making it really clean.

Then I would have BLheli, and be able to mess around with them a bit more.

Do you think they would be fine. The smaller size means heat dissapation concerns me, but then again they have come along way. Would I be fine on 4s running a aggressive prop?

should be, im also currently building a 180 sized, 20A blheli ESC's, 2300kv motors, going to be powered by 4S
got a small selection of 4" props to test the differences and measure the differences in the drawn amperage
but obviously couldnt literally test it yet (still building)

so maybe some one more experienced could confirm the whole story :p


Hostage Taker of Quads
Staff member
The newer, smaller 20 ESCs have three things going for them . . .

- Better FETs -- the improved chips can handle more current with less waste heat. less waste, less need for cooling.

- No UBEC -- every ESC needs a voltage regulator to run it's own processor, but adding on a linear reg that generates 10's of mA instead of 1000's of mA makes a HEAUGE difference in how much heat the UBEC generates. the downside? you now need an external BEC to power the rest of the airframe, but that's been moved tot the PDB these days.

- clean design -- the F-20A was a very serviceable ESC. responsive and easily reprogramed for it's day. Trim and lightweight, it was not. Many ESCs from a few years back suffered from sloppy design. Build it big and inefficiently, but it starts to overheat? slap a big heatsink on it, and put it up for sale. After all, who really needs 20A out of an airframe weighing 150g? The market has done a tremendous job in pushing ESCs to be designed with weight and size in mind.

I have pushed the littlebee 20's to 20A and they get very warm, not hot. As far as 2S vs 3S vs 4S . . . So long as you don't exceed the breakdown voltage of the parts or overheat that tiny regulator, the ESC could not care less what the voltage is. All it cares about is heat, and it's current through the FETs that generate the heat. So long as your motor isn't demanding more of the ESC than it can handle (how aggressive is "aggressive" for a prop?), you won't have an issue with it.