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:
- DYS
- Multistar
- Turnigy
- T-Motor
- Afro
- Motortron
- Quattro
- 3DR
- Spider
- KDE
- ZLW
- Aris
- EMAX
- 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.
Replies
The above reference definitely does not apply to the above testing, which is done well and shows the same as i've found (except that they haven't as yet tested the above ESC).
Words, in my book, mean nothing unless they translate to actual measurable performance. Marketing tries to do the opposite ... make words mean everything. Betaflight, regenerative braking, 32 bit ... are all great only if they can show measurable response difference with the props on in terms of actual thrust response.
So stick to the test data. Show me an ESC that outperforms the "old" tech in response ... please. I'm still waiting ...
Forrest-
Since you still didn't answer my questions, I looked up your pet ESC on the DYS site.
http://www.dys.hk/ProductShow.asp?ID=51
As I suspected, it does not support either 1-Shot125 OR active braking of any sort.
These are MINIMUM REQUIREMENTS nowadays for a "Race-Ready" ESC.
THAT is why Ryan never bothered to test them. They're stone-age bunk.
They are AIRPLANE ESCs with 3 generations out of date SimonK firmware from 5 years ago. They are made for the "AP Airship" market; quads that haul cinematographic camera gear and NEVER leave a hover.
They are NOT "Race ESCs" by ANY definition of the word. PERIOD.
Today's Race ESCs handle 60A surge current on a 20A rated ESC, because that is what today's racers demand. The latest generation have 32-bit Silabs F390 processors, because 8-bit processors can't keep up.
FPV Quads are another thing altogether. They fly high speed, mostly FFF in 40-60° forward tilt, and they fly acro, flipping and tumbling and piro-ing like a 3D Heli.
For that you need to not ONLY be able to accelerate rotating mass quickly, you ALSO need to be able to STOP the props just as quickly.
These MB30040s are stone-age crap that simply doesn't cut it anymore.
Now don't get me wrong; I LOVE me some DYS. I have their motors on a dozen quads, and their BL20A ESCs on several and their XM20As on another.
You want to see some SERIOUS performance from DYS targeting REAL RACING applications? Look at the XM20A and XM30A.
http://www.dys.hk/ProductShow.asp?ID=186
http://www.dys.hk/ProductShow.asp?ID=209
Yeah, you read that right. 50MHz clock. 3000hz refresh rate. 9.2 freaking grams.
The MB30040 are ancient boat anchors don't even hit on their radar screen, they're so long out of date. 500Hz? PuhLEEZE. 39 FREAKING GRAMS?!? :rolleyes:
That's 1 ESC that weighs more than 4 real race ESCs. That would mean adding 90 grams of unsprung weight to a 500 gram build. The math is pretty easy. NO FREAKING WAY. ;)
And even those DYS are what we consider to be third or 4th string; the X-Rotor 40As are STILL tougher and faster. As are the KISS 18A and even the Zeus 20A/FVT LB20s.
So REALLY. These are NOT a "Muticopter" ESC by today's standards. They're a Heli ESC at best, REALLY an Airplane ESC with slightly modernized FW.
The guys who are buying the ESCs I directed you to are the guys who fly at the Drone Nationals and the World Drone Prix in Dubai. I PROMISE you, they aren't flying ANYTHING like these antiques. I know several of them personally.
Cheers,
Paul
As a capitalist, i'm glad to hear that marketing hype still works. As an engineer, i'm smiling because some people ignore hard data, which is how we win races against flyers that have "minimum hype requirements".
Oh ... and keep believing that the DYS weighs a lot, so please don't read the next line.
Naked, the DYS ESCs weigh 13 grams and still outperforms a 1 gram ESC with on a net-thrust basis on acceleration. No surprise if you understand heat loss in circuits that are too thin/wide.
love the fact that flyers are going the snowboard route with great imprints on their electronic platforms
I thougth that I was crazy building a racer cuad if I'm too sucky too to race FPV, only to entusiasm young boys, and take pictures, but I'm not alone in this world :D :D
Since when isn't FPV racing real racing? And it's the fastest growing segment of the multicopter market.
Hallelujah! I heard it's on track to be an Olympic event for 2018. X-games is weaksauce.
@Paul Great to see there's some innovation going on in the ESCs, even if it's very specialised. The fact we're effectively doing D2A A2D D2A conversions from the FC to ESC to Motor in the 21st century is crazy.
I think Forest's title for this blog is pretty silly, it's clear that his interests lie within a particular defined set of parameters that don't cover every eventuality. Yours with fpv racing, I put my ESCs in CF tubes so that pretty much rules out every ESC Forest has tested, others lifting much larger UAVs won't find anything here of interest etc etc. However, what he's doing is interesting as base research and he is looking at the most common set of parameters - the general small/midrange UAV - so it probably applies to the vast majority of the bell curve, so to speak. The type of ESCs you're talking about have little interest to 99% of the UAV community outside of fpv racing. Which is fun, and makes headlines with pretty leds, star wars getups and real-life computer gaming, but is probably a drop in the ocean of the overall UAV market.
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