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
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!!!!
http://www.walgreens.com/store/c/reach-clean-burst-dental-floss-cin...
and here is the states, it's free. the dentist is always trying to get rid of the stuff.
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 :)
I use zip ties.
Bullet Weight - There is a distinct advantage to large bullets in that they are less likely to accidently disconnect. And if i like to save weight on bullet connectors, then why do i sometimes use an XT60 (6.2 g) on the main battery plug?
Given that optimal wire size drives the bullet connector size (the wire must fit into the shaft), on a quad with 20 bullet connectors between the ESC to motors and battery (weight varies between connector suppliers):
- 3 & 4 mm bullets add 23 to 31 grams
- 2.0 mm bullets add 11ish grams
- 0.8 mm bullets add 5 grams
So for an FPV racer using 2 mm versus 3 mm bullets, the acceleration of the lighter ship will be 5% quicker! That is clearly enough to win or lose the race.
But small bullets come loose. Yes, they can. All lines running to/from the ESC should be tied down (use dental floss to practice knot tying or use slightly heavier zip ties). Do this no matter what the bullet size. If they are tied down properly, they will not come loose in flight. Ever. Check all connections after a crash for wires that pulled and periodically. If the ESCs are under the prop, connections are easy to inspect.
So why slow down your racer with more weight? Why shorten flight time? When all you have to do is learn how to tie a square knot using Minty Floss (my big bro taught me how :-).
Why do i sometimes use the heavy XT60 connector? I'm a hypocrite? Excluding the 250 Racer that can easily spike to 60 amps, most of my ship don't exceed 20 amps. The XT60 is 5 grams heavier than a right-sized connector on those later ships. If going for a world record, i'll take the extra 30 seconds and tie down the battery to the power module connection. But for convenience of every day flying i want the ship to:
- be easy to connect and disconnect to swap batteries without having to tie them down
- on a crash, to jettison the battery, which the XT60 performs nicely (saves the ESCs and frame)
I was in doubt if use connectors (in case of crash they can disconnect) on my future racer or soldered wires to save weight, perhaps connectors is a better choice?
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.
I usually use the stock wires on the ESC and do wire-to-wire solder joints.
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.
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 :(
-
9
-
10
-
11
-
12
-
13
of 25 Next