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
Good point Paul!
There is a racing car and there is an off-road car... or even a truck... and then is a tiny Smart. So there is no universal car (read ESC :-).
Love it Paul. You perfectly reflect most FPV racers. My brother Jim and I worked with one FPV racer this past few months to improve his ship after he won the Arizona Open (an amazing pilot). He was just like you. It finally took repeated side by side drag races to show him that the test data doesn't lie. He got tired of being beat by "old" tech. And started listening and adapting.
You can apply all the tech you want to ESCs and make them as complicated, expensive, and small as you want, But if they don't:
- generate a higher max net-thrust (thrust after is moves itself)
- generate a higher response Hz as measured by thrust change
... then all that glitz and tech talk is for naught.
so you keep racing your glitz and long-words. my guys will start racing what actually generates the quickest acceleration.
Have you actually tested active braking on a response meter? And I'm not talking in the lab. I'm talking put a prop on the darn thing and test actual thrust changes?
i'm trying to dispel the impact of advertising and hype on pilots with actual test data that is realistic and takes into account how big and heavy the darn thing is.
Rather than "brain storm", do me and the FPV community a favour, "try storm". The result will astound you.
So please help. Tell me what you think I should test. If i don't already have it, i'll get it. And test it. Deal?
Forrest -
One simple question:
What is the max E-RPM on your ESCs?
What we call "performance" is power to weight in the range of 8:1-10:1. An average build is pulling around 1KG per motor on 5" props and in excess of 1KG thrust per motor on 6" props with a 500-600 gram quad.
On top of that, we expect it to handle like a hummingbird on crack, so we need not only fast acceleration, we need massive braking performance. Do your ESCs even SUPPORT active braking?
Simple straight-line performance is totally 2008. ;)
Sorry... your ESCs just can't cut it. What we consider to be a total "Team Nana" build would leave any quad built with those ESCs in the dust in the first turn; they just can't turn the RPMs we NEED for the way we fly. Modern racing ESCs are working so fast, talented folks like my friend RS2K are writing entirely new protocols for them to talk with the FC because PWM is just plain too flupping slow.
I suggest you scope out Quad McFly's performance database to see what I'm talking about, and to see the kind of ESCs and motors we actually RACE WITH.
http://www.rcgroups.com/forums/showthread.php?t=2492809
http://www.miniquadtestbench.com/
Once you see the setups actual racers use, then you'll understand; you're comparing a Cummins TurboDiesel to a V12 Ferrari. If we were RACING dumptrucks it might be a good idea, but we're racing Formula 1. ;)
Right now, this is the fastest growing segment of both QuadCopters AND Model Aviation; we just had the World Drone Prix in Dubai, where a scary-talented 15-year-old kid won a cool 1/4 mil. Quad Racing is right now on the cusp of going completely mainstream; it's the next X-Games. Seriously.
Cheers,
Paul
This is where I usually put some pithy remark.
Yes. I'm familiar with that site. Excellent work.
- That site list the best rated ESC is the HobbyWing X-Rotor (i tested the 40A version)
- His site did not test the 40A DYS Multicopter, which
... beats the above in max net-thrust (defines the top end of acceleration)
... beats the above in nnet-lift efficiency (g/w after it first lifts it's sorry ass)
... they match response
- So if that is the ESC you are using, don't feel bad. You are almost using the best.
Too many manufacturers and pilots rely on the wrong criteria.
For example, RPM. One doesn't win races by a motor that can accelerate and decelerate without a prop. The criteria that matter is when you put the iron to the metal and test ESCs on 250 FPV Racer motors. Then the only criteria that matters (having blue blood doesn't count):
1) Thrust acceleration (+ and -) is the only criteria that matters in terms of response
2) Maximum Net-Thrust (thrust generated after lifting itself) determines how far acceleration can reach.
So those that want to look at meaningless criteria, "Red is the only color I consider", might be happy, but will lose races.
Confession: I'm too sucky of a pilot to race FPV, so hats of to those that do. But my brother an i sponsor an FPV winner. So yes, we have a lot of experience in building ships that haul ass and can turn on a dime.
Offer and Challenge to Other FPV Champions: If there is a proven champion that is open to improving his FPV racer ship. I'll be glad to help. Every change is carefully done with through testing first. But the final test is in your hands maneuvering and racing the ship. I can guarantee a 20%+ improvement in acceleration of any champion's ship. The only question will then become, "Are you good enough to fly it to it's full potential?"
If you are referring to the above mentioned person doing testing, he does test with multiple props and motors not motors without props, The dys40 is a good choice for low kv motors. The F330 base esc's are a thing of the past for fpv racers. The f39x's are the way to go. The f330's can not keep up with Betaflight's full potential. Most serious racers use Betaflight and are going for the maximum potential and these units will not handle it. Now for normal flying these are very good choice.
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
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