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
looked at their test. You can see why many pilots are taken in by marketing. Most pilots don't have the $$$ to buy the necessary equipment nor do they desire to take valuable time away from fun FPV flying to create metrics we can use. Instead they do the "Charmin" test. I do that test myself and it is a good way to discern large differences between products.
My message to ESC designers and manufactures is this ...
A good coach focuses on fundamentals first. Once optimal, then the coach adds smart play.
My message to FPV racers is this ...
Ignore the hype. Focus on results.
I will take your advice. But at the moment, teaching takes 2nd fiddle to testing and finding a method for pilots to reach that data. The only way to teach a FPV champion, is to beat him with a ship built by thorough testing. Then and only then do they listen.
I LOVE the SN20A; it is the same ESC as the BL20A, only with outdated SK firmware. We buy them when they go on sale and flash BLHeli on them to turn them into serviceable entry-level acro ESCs. :D
Cheers,
Paul
for anyone that wants, mail me an ESC. Friend me so i can send you my address. tell me if you want the comparison results published or private.
Forrest, with all due respect... you have no idea what you're talking about, at least where racing is concerned. Those DYS aren't even in the top 50 for a racing ESC; they're ancient tech with crap FETs that switch too slow and have way too high on-resistance. A real racer wouldn't even CONSIDER them, they're what we'd call a "boat anchor".
Today's cutting edge ESCs are running faster 32-bit processors than the FC in your quad, and they have to because of the speed and demands for twitch-trigger responsiveness that racing quads and acro pilots demand. The FETs have such low on-resistance they have to have dedicated drivers, and we consider active braking to be a minimum requirement, NOT an option.
You're putting this kludged-together airplane ESC up as a paragon of ESC performance, when I binned ESCs that outperform them on their best day years ago.
We're running excess of 30K RPM nowadays dude... that needs a lot smarter, stronger, and faster ESC than any Atmel-based processor can deliver, and certainly that finds even the latest SK firmware sorely lacking.
Oh, and we use velcro wire wrap to keep our wires out of trouble. ;)
mnem
*Toddles off to ded*
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?"
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