Worlds Best ESC - Making it Better

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.

You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –


    • 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  :)

  • MR60

    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 -

    • @Forrest

      Nice test-stand! I love the fact that you put it vertically. So the in-flow as well as the out-flow are unobstructed. Very nice job. Thumbs up!

      That would be a good material for a discussion :-)

      • MR60

        hopefully this answered your other question on the criteria for an ESC and how to test it.

        1) Response (highly critical to FPV racers and response in wind/turbulance)

        2) Net-Max lift (now much the rotor (ESC, motor, prop can lift after lifting itself) ,critical to your heavy lift ship

        3) Net-Efficiency (critical to sensor ships that need to travel to their destination, perform a long inspection, or maintain a position of surveillance)

        There are many other criteria for a designer:

        - cost

        - reliability/durability (i like the burn-in process of your Herkules)

        - size/fit

        - brand

        - etc.

      • MR60

        Thanks you. I've also tried about a 10 to 15 degree angle (normal ship attitude). It doesn't make a difference as long as the prop is out of prop wash and not impacting the load cell.

  • Wow, Mr. Jack___ sure can de-rail a useful conversation with the best of 'em!

    @Darius, the carbon footprint caused by the energy you expend typing this drivel just killed a baby seal... Please stop killing baby seals... just stop.

    • Okay.  Now I have a real problem with the 'wet noodler'.

      He is giving bad advice to a newbie who has no idea that he's being fed manure by a horse's ass:

      "Manual control is fuzzy logic based."  No poop, Pedro!

      What should I do?  Moderators?

      • Maybe he's an AI that somebody is testing on this site.

        • MR60

          could be as it looks quite robotic (borderline idiotic). In case of an AI it requires some improvements.

          Other possibility : it is an alien using an automated traduction interface.

          • 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 reply was deleted.