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
Oopps ... before you write you might want to read. Further back is this link:
http://diydrones.com/forum/topics/standard-industry-wide-rotor-test...
1) Net-Lift Efficiency (nothing that FPV Racers care about)
2) Maximum Net-Lift (what impacts acceleration of the ship when you floor it)
3) Responsiveness (how fast thrust is developed)
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.
does someone have one they can send me? i'm seeing back ordered.
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!
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?
Now my time to disagree ;) . Dental tie isn't more difficult to break in a crash ? it's possible to damage the wires with it?
Cala's always right, Cala's always right, Cala's always right. That's the mantra I repeat every morning except fortunately for my health and safety I replace "Cala" with the name of my wife :-)
Never did the test before, so here we go.
- took Waxed Dental Floss (mint flavored) and tried to cut through electrical wire using 50 saw actions
- took Zip Ties (small, not mint flavored) and tried to cut through the same wire using the same saw action
Here is a photo of the test
Here is a photo of the test result
That surprised me (the zip tie)! Was this test harsh (50 hard pulling saw cuts)? Probably. The zip tie didn't cut through to the wire until saw cut 30. At Boeing, the Material's guys would rig up a vibration chamber, a chaffing device, and try to do an official wear test.
Think that i'll use Waxed Dental Floss and check wear after every crash.
Thanks Cala for having me do that test (Cala can get me to do anything ... she just sends a wink icon in the text and i fall apart ... the joys of being an old fart).
You are a serial tester LOL; I figure your husband with her vacuum cleaner not working well and you in the living-room testing different vcleaners with different dusts calculating the air velocity and dust mass LOL; but your test are very usefull for me :D that are the other extreme.
Now, the two materials damaged the wire so, anyone looks good, correct?, In general I try not to tie wires, but sometimes I need this is usefull for me http://www.hobbyking.com/hobbyking/store/__23571__Spiral_wrap_tube_...
obiously not tested (I'm only test when I crash and learn GLUP! ) For my crash experience, components need to have the possibility to jump from the ship not to be damaged by ties, frame or other components.
You have another work now to test different materials that are secure for flying but not damage wires during crashes ;-), little velcro?
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.
I'm going to have to implement something like this to my racer with flat arms, thank's
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