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.
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?
Wow ... great question. I'm not real comfortable soldering ESCs. I like to solder once and praythe solder doesn't go somewhere it isn't supposed to. Thus i prefer bullet connectors and dental floss. But if you are comfortable with soldering, you really only need to change that connection after a really big crash that takes out the ESC or motor.
Maybe if i get down there you can teach me your solder technique :-) I'm afraid is isn't much better than my flying technique.
apology accepted ... it's ok to be passionate and i truly appreciate your kind words.
Solved: I keep how they come, I'm not comfortable soldering, ...I hate it; if you not like to solder them, I forget ;) , sorry I can only teach you how to pile tin.
....but I never suffer an unsolder crash Ehhh!!! LOL ................yet :(
I usually use the stock wires on the ESC and do wire-to-wire solder joints.
I use zip ties.
Just looked at your wire sizing worksheet and input a few numbers. I like the green banding. Very useful.
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).
if solder, then maybe don't use nylon motor mount bolts? we use nylong motor mount bold to help the motor/prop shear off the bolts and eject during a crash (helps save the motor/prop and the ship is the theory). but that also sort of mandates that you use connectors on the ESC so they can pull free without taking the ESCs with them.
So if solder, maybe use Aluminum bolts that are quite a bit lighter than the steel bolts.
Any experience on this Cala? when you crash, do you motors stay on the motor mounts keeping the soldered ESC protected?
yes ... must safer than messing with the solder on the ESC. sometimes i cut the stock wire short and solder to the stubs using the right-size motor wire and then cover the joint with shrink tubing.
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?
That little wires are my concern not to be damaged with vibrations in the time; I try, once an year or less to dissasemble them and inspect and, time to time, I find someones damaged, last week I noticed wires from motor to inside Tarot CF tubes in my new quad becoming damage, I sanded all the edges but It wasn't enought :( . Any recomendation is welcome :)