That's a bold statement ... Worlds Best. But it's even larger than that. Not just Worlds Best, but best for most all applications less than 30 Amps (limit of the tests). That means:

- duration ships that only pull 2 to 8 amps per rotor

- most all 6S and smaller ships (exception of nano-ships)

- any-size FPV racer

- any other ship in between

Why almost any size? Shouldn't a small FPV racer use a smaller and lighter ESC for response? Yes, if it does better on a net-lift response test. In other words, when you penalize the ESC for it's weight, is it still better and faster? What i continue to see is ESC manufacturers downsizing critical components of the ESC at a net loss. They weight savings is lost because of greater thrust loss and response. In other words, this heavier ESC will out accelerate, in the real world, a smaller and lighter ESC.

Why post this? To move technology forward, we need to report to industry what works and what doesn't. For some reason (i don't know why), this ESC works better than all others tested:

- for generating maximum thrust from the motor***

- for net-lift efficiency or the grams of weight it can lift (after it lifts the rotor) per watt

- for response (how fast it can generate targeted lift)

These tests were conducted on multiple days on multiple rotors of highly variant size, always being immediately compared back to another DYS 40A multicopter test to ensure that the baseline wasn't changing.

The ESC that dominated is a DYS 40A OPTO Multicopter using SimonK. The photo is included because there are two others that carry a similar or same name.

- Not the white cover DYS BLHeli 40A

- Not the one that is says "Programmable" versus "Multicopter" in the blue/purple band across the front

Have i tested all ESCs? No, but if you are convinced you know of one that would work better, let me know. I've tested most all of the following and one or more of their variants:


- Multistar

- Turnigy

- T-Motor

- Afro

- Motortron

- Quattro

- 3DR

- Spider



- Aris


- AutoQuad

- Exceed

- HobbyWing

- Lumenier

To do a test like this, a highly repeatable and finite test stand is needed. It took a while to develop one but what works is one that:

- measures (at a minimum) volts, amps, thrust, motor temp (shoots IR up the aft end of the motor)

- eliminates harmonics between the rotor and load sensor (this proved difficult but achievable)

- is calibrated and proves repeatable within 1.5%

- controlled by a system that can precisely repeat a rotor test (uses a Audurino Mega)

- directly feeds the data into Excel for analysis (uses DATAQ)

- uses a test script that produces repeatable results

- uses a test procedure that minimizes repeatability error (used average of multiple tests)

How much better is this ESC?  On average:

- 4.4% higher net lift (after it lifts itself)

- 2.3% more net-lift efficient (usually the larger the better)

- from more than twice the response or the same response as other ESCs (usually the larger the better)

                                                       So how to make it better?

Step 1: Strip it naked. See photo below.

           ... remove the cover

           ... remove the heat plate (better to locate the ESC under prop wash to run cooler, see below)

Step 2: Right-Size the bullet connectors or wires (see above where heavy wires are replaced by 2mm bullets)

           ... remove the large bullet connectors or wires

           ... replace them with ones that are the most net-lift efficient (where heat loss = weight loss)

Step 3: Seal the ESC. Seal it with Electrical Sealant to protect from moisture and conductive dust

           ... tape or plug connectors and wires

           ... repeatedly spray each side from different angles

           ... a mistake i made was not sealing the bullet connectors and solder

               - don't tape them off like i did

               - insert a male connector into the end of bullets so sealant doesn't get inside them

Step 4: Locate ESCs under Prop Wash. See photos below. The turbulence generated by the prop does not adversely affect lift when the ESC is placed on edge to the prop wash.

           ... Use something non-conductive like hot glue to bond the ESCs to the motor mast or spar

           ... Face the FETS (the little square warehouses or Fire Emitting Transistors) to open air

           ... Protect the ESCs from below from ground contact (not needed here because of clearance)

back-side with hot glue

front-side with FETs completely exposed to open prop wash

Step 5: Tie up wiring. Use dental floss to secure wiring away from the prop.

***Note: The T-motor Air 40 in high-timing mode (an option) generated higher thrust, but at the sacrifice of efficiency and motor temp. Also, the T-Motor Air 40 was 2nd best and close in performance. If you are using an Air40, it probably isn't worth switching.

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forget your crazy idea to seal low dissipation energy Mosfets by Fairchild 

with low thermal conductivity sealant by 3M

Words Best ESC is coming with finned heat sink in open window.

Just read , watch and forget your crazy ideas

Good luck

It certainly looks a bit robotic.

There's been some really good solid information shared by Forrest on efficiency of ESCs, and the way to reduce their weight. It must have taken a lot of precise testing and considerable time to identify the best ESC.

It really is a shame that one person is trying to ruin this thread.

"This is the most stupid idea ever discussed on the public forum"

Oh goodness gracious no, you've introduced far stupider ideas.  Allow me to list just a few of them off the top of my head:

 - Using washing machines to create magic vibrating tables to solve one of your invented syndromes

 - Grounding all pixhawk until you've certified them

 - Nobody should fly where there is any wind (essentially outdoors)

 - RTK GPS is a figment of everybody's imagination and can't actually produce the accuracy that everyone thinks it can

 - Wind farms create.. no wait, allow me to quote your own batsh*t crazy words on this one:

"Lights blinking torture known as "light flickering" or "stroboscope effect", is generated by slowly rotating wind turbines against the sun light, generating infrasonic stimulation of your mind, elerting your brain at night, overclocking brain waves from 15Hz-20Hz (dream relaxation) to 30Hz-40Hz (alert) resulting in Chronic Fatigue Syndrome."

Uh huh.

If you know the answer to everything, why don't you **** off and produce them, and leave us amateurs to blissful experimenting ignorance?  You haven't come up with a single positive idea or product that I've seen on this forum, just continuous negative trolling.  Go away.

Painting over the pixracer will destroy the barometer, ruining the flight controller.

Yes, taking in consideration to protect it and the connectors as Forrest advertise, but baro have it's oun sponge protection so is no problem; but thank's for advertise, in case,

That's a nice AIRPLANE ESC...

Some are curious about how the data was attained, referenced other test sites and methods, and are appreciative of the test effort ... so started another thread on that ... which i find fascinating (OK ... i confess ... some think i should do more flying an less testing ... i'd definitely be less of a sucky pilot if i did that) :-)

the thread asks the question, is it time we move away from the really cool but theoretical tool, Ecalc, and base our decisions on reality? i think it's possible. Do you?

The thread references the following two videos that led to this data that got me thinking about ECS efficiency.

Efficiency -

Response -

I mentioned the link between the heat produced by electronics as a mathematical trade on component weight and was asked to share. OK ...

- a thick 12 AWG wire produces little heat (watt loss) when connecting the battery to an ESC.

- but it has more weight than a much thinner 20 AWG wire and thus the ship has to use more amps to lift it.

- so where is the trade? is 12 AWG right-sized? is 20 AWG right-sized? Or something in between?

This is trade is critical on optimal ship wiring as ESC typically come from the factory with too-heavy wiring. This trade is also contrary to normal wiring rules of thumb (e.g., don't use a wire that makes voltage drop by more than 5%). Most motors used in industry do hot have to expend additional amps (causing more voltage drop) to lift themselves up in the air as do our electronics. This dirty little secret changes everything.

This is how it works mathematically:

- wire has measurable mass. so weigh 24 through 10 AWG wires

  ... this seems simple but it can get complicated

  ... there is Copper wire, Aluminum wire, & wire with thick and thin insulation

  ... but this is doable (i use what i consider to be optimal wire, motor wire, to simplify)

- convert the mass of the wire to watts. this is easier than you think

  ... varies from ship to ship

  ... easy to measure. just fly your ship and track watts in the log then add or subtract mass and fly again (e.g., change the battery size)..

  ... but if going with light-weight efficient designs, i can save you the trouble. the number is about 0.15 watts per gram.

- so you can now calculate the watt loss of any wire system due to mass = mass per unit-length x total length x number of wires x # of rotors

- you can also calculate the watt loss of any wire system due to size (AWG) = resistivity x rotor-amps^2 x total wire length x # rotors

- you know what amps per rotor will be from the design of your ship or from testing other similar ships. choose an amp rate that will be typical for a flight mission

- plug that amperage into the equations. add up the watts from heat loss to the watt loss from weight and you get total watt loss

- use the wire that generates the least watt loss.

You can do all that, or just use the attached worksheet (dang ... you saw that coming)

- change the purple cells to the specifications of your ship

- choose the wire size for each part of your ship based on the color tones (green is optimal)


Are you spying my next work Forrest???? ;) I have some lighter esc and lighter wires to lightweight my ship, but I go by female instinct, now I have the obligation to do some calculations, now not excuses :( 

Really I choosed the new wires with an older sheet that you share, thank's, if not, I have to carry extra weight in case. very usefull your post and very clear to explain for dummies that don't speak english  :)

@ ESC manufacturers - Option 2 does not cost much more than option 1. Shrink wrap can then be applied as before and then in an additional but low cost process, stamp-cut away to expose the finned aluminum. At least consider stamp-cutting an opening on the Al slab that you currently use. 


I have already provided you with weblink to manufacturer of Option 2 ESC.

plastic wrapped, unwrapped, bare,  radiator mounted, finned Al stab,

every option, design already manufactured and open market offered.

What you call:


Note: There is an adhesive gel/cloth between the FET and Al slab. It too is approximately the same surface area of the FETs and serves the purpose of minimizing air gaps between the FET and Al slab."

What you call "gel" is in fact high thermal conductivity paste, gel, glue.

Why 3M sealant is not ok ?

3M sealant has not been certified or advised by Fairchild Semi for painting Mosfets made by Fairchild Semi.

Low power dissipation modern Mosfets by Fairchild Semi don't require large radiator, finned Al stab at all.

Mosfet's thermal energy distribution has been tested and verified with the use of thermal cameras at labs.

So I can assure you, manufacturers of ESC are accountable for flaws in design, manufacture, if any, and can be contacted , reached immediately in case of ESC failure resulting in drone crash.

Anyway, my Open Technology Park is ready to fully support your efforts in design and manufacture of better ESC for drones.

Every project can be pretested at the OpenFabLab with thermal camera 

and any lab equipment you find required or necessary to succeed.

Wish you all the best and prosperity in private and business life.

Open Technology Park

Usually i don't like Darius comments...but this much BS and pseudo science ideas from MR.Forrest is unbelievable...and he is doing that for years trying to get attention with bombastic best esc,world lightest multi with worlds best materials known to mankind,worlds longest flight,mr.60 what a joke....Mr.Forrest,did you ever try to visit some institution for people like you?

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