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:
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.
I never hard crash................yet (touch wood we say here).
My bigger crash were one from 10 mts :leg damaged and alum arm crooked.
I try my ships build crash resistant because it's not easy here to buy spare parts and I don't like to break nothing after a crash I cry a week :( Men at the club have impressive airplanes and when they crash they pick up the parts and....nothing happens here :]
My Esc are with standard plugs in case and tie with two little zip tie arround the esc for the moment.
i've also used dabs of hot glue to secure wires. that pulls away easily and does no harm but can weigh a little if not careful.
i typically only tie down the wires under the prop so that bushes and turbulence don't move the wires to the prop. you'll find that waxed floss is also safe. unlike the test that used constant pressure on the wire, a knot can't do that. if it did start to cut into the insulation, it goes slack as the diameter of the loop stays constant and the wire by definition has to be getting thinner.
The wind shifts my hair. I hear a slight hum. I feel eyes on me...
What is that smell? Cinnamon?
Oh crap! There's a DRONE in the air!!!!
I'm going to have to implement something like this to my racer with flat arms, thank's
and here is the states, it's free. the dentist is always trying to get rid of the stuff.
Forest, do you have your test data someplace where others can look and contribute? Also do you have similar tests for motors and props?
Your work is greatly appreciated, thank you for your contributions to the community!
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. ;)
*Toddles off to ded*
LOL Thanks for risking your fingers in the name of hokey science ;)
The real question here is not marginal downward force on the ESC, but potential loss of thrust from the prop. Have you measure the actual prop thrust with and without the ESC?
I think Forrest should also test this ESC --> http://flyduino.net/KISS-ESC-2-5S-24A-race-edition-32bit-brushless-...
It is one of the best if not the best ESC for racing.
Well, what are your criteria? Obviously Forrest isn't testing responsiveness, so perhaps it is not appropriate to mention racing in the OP. But for my application, long endurance, this ESC is king.
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?
it has taken about four years to develop a test stand accurate enough to handle the little 6" FPV rotor systems to the giant 36" 12S 50 amp beasts.
so yes, over the past four years i've documented a lot of tests. the problem is that over those four years i've rebuilt the test stand four times because i was never happy with repeatability over time. now i am. so finally test data will be valid with the passage of time.
don't know if you saw this. http://diydrones.com/forum/topics/standard-industry-wide-rotor-test...
i've been trying to post results of testing, but you are right. i need to start organizing the test and test results into a form that folks can access. i'll work on that. in the meantime, any specific questions about motors and props?