Thread Tools
This thread is privately moderated by carcynic, who may elect to delete unwanted replies.
Sep 08, 2014, 08:47 PM
Fun until flying robots attack
carcynic's Avatar
Thread OP
Mini-Review

REVIEW: EMAX 22042300KV Motors


I was honored to be selected by EMAX to do a review and Flight Test of their New 2204 2300KV Motors.

I received my motors on 06 September 2014. What follows is not a full review, but I will update this with more posts in the future.

I mentioned to EMAX that the EMAX 2204's would be replacing the 2208 motors installed on my BlackFish 250 Quadcopter. For more information on the BlackFish, please see it's build thread, here:
https://www.rcgroups.com/forums/show....php?t=2172022

Before I installed them, I weighed one of each motor:

The Angel 2208 2600KV on a scale, showing 44.8g

Here's the EMAX Motor:

The EMAX 2204 2300KV on a scale, showing 26.5g

(Yes that is an old scale, but I prefer a true laboratory balance over a cheap digital spring scale.)

Note that I have to include the collet on the Angel's to make it fair. In both cases, I am showing everything needed to attach the prop.

So that is 18.3g less, per motor, or 73.2g less for 4 -- Almost a 15% weight reduction for the quad.

Weight, not advertised thrust, is really important for a small 250 size quad. I am never going to get near the peak of the efficiency curve for either motor when I am limited to 5" props, and smaller batteries. (More about the props later.) Weight savings, however -- on a small supposedly manoeuvrable racing quad -- is golden.

Next came installation:

The 2 motors have exactly the same mounting holes -- Size, orientation, and spacing, so mechanical installation was "Plug and Play".

I should mention that the Angel 2208's came with mounting adapter plates, but the EMAX 2204's did not. That said, I have never used the mounting plates on any of my Quads. I now have dozens in my parts drawer.

Similarly, the Angel Motors came with bullet connectors (uninstalled), and bits of heatshrink tubing. The EMAX's did not. Since the bullet connectors included with the Angel Motors fit the ones already installed on the ESC's motor leads, I actually was using them. Also, since many ESC's do not have a reverse setting, having bullet connectors makes setup much easier.

Including bullet connectors (uninstalled) with the bits of heatshrink is a nice touch that EMAX may want to consider. It gives the builder the choice.

Never-the-less, chop, solder, and re-solder I did, and here are the EMAX 2204's installed on the BlackFish250:



These motors are far shorter than the previously installed ones. Not just the 4mm from going from a 2208 to a 2204, but much more from the fact that they do not use a collet or prop adapter.

Obviously, most installations are not "retro-fits" like this, but you do need to be careful to make sure a lower motor will fit. There isn't much clearance between the props and that connection to the camera:



As everything in engineering, direct prop mounting (like this), collets, and prop adapter shafts all have their advantages and disadvantages.

This way (direct) has the fewest possible points of failure and the lowest mass (remember that rotating mass is even worse than static mass). Personally, I don't like either collets (like the Angel's) or direct (Like this). I prefer a removable prop adapter shaft. The benefits out weigh the disadvantage of the extra weight, and the remote possibility that all 3 screws could come out.

It may -- OK, it does -- make sense on a smaller motor such as the EMAX 1804-2408's, but by the time you get up into a 22mm dia. core motor, you are talking about a quad that can lift the extra few grams.

The benefits come in being able to replace them if they get bent in a bad crash, or if there is just a problem with the threads from, again -- crash damage, over tightening, etc.

Lastly, for this post, I want to talk for a moment about ESC's.

I have had problems with High KV motors destroying certain ESC's (with certain settings).

See this thread:
https://www.rcgroups.com/forums/show....php?t=2210831

I have had the Angel Motors destroy a total of 4 ESC's. Since that thread was active, I have had another violent ESC failure with a Hobby Wing SkyWalker 30A ESC even with it set to "middle" timing.

It's not just me, or the Angel 2208's or the Hobby Wing ESC's.

The package the EMAX 2204's came in state:
Quote:
"Different ESC's perform better or worse with certain motors, If the motor makes unusual sounds, try retiming the ESC, or use a different ESC. Different ESC's will give variations in performance and power"
(Spelling and grammar corrected as an additional service to EMAX)

High KV motors, or any specialized motor -- of any brand -- is going to have issues (possibly violently) with certain ESC's.

Heed the above warnings.

Check the ESC settings before arming the motor (again, that is any brand of high KV motor). During the first few run-ups, or if you change props, ESC settings, etc., be especially cognizant of roughness, jerking, or noise.

If you have the ability to do so, use a current limited power supply for a first run-up.

If you do have an issue or failure, do not be too quick to blame either the motor manufacture or the ESC manufacture, it could be just an incompatibility between the two.

Note that even the relatively small difference between a 2300KV motor and a 2600KV may be enough to alleviate some of the ESC compatibility/timing problems. In other words, a 2300KV motor may have fewer timing related issues than a higher KV motor.

I am now using Hobby Wing Skywalker 20A ESC's (as shown in pictures, above) on several builds with several different brands of 2300KV to 2600KV motors, and I have not had a problem with those ESC's.

Please check back for more of this review, the actual flight test results, more pictures, and possibly a video.
Last edited by carcynic; Sep 09, 2014 at 03:34 PM.
Sign up now
to remove ads between posts
Sep 08, 2014, 08:51 PM
Fun until flying robots attack
carcynic's Avatar
Thread OP
Place Holder:

Prop Nuts:

Prop Sizes:

BlackFish 250 Quad w/ EMAX 2204 Motors -- Scream Test (1 min 7 sec)


Scream Test of the EMAX 2204/2300KV Motors with GemFan 3 Blade 5030 props (plastic). Will These motors scream them like others are reporting with 2 blade 6030 props or like the Angel 2208/2600KV motors did to these same 3 blade props?
Answer: No. It sounds close, but it is not the scream.
Still plenty of "Punch", as you can see.

Note that these not the props I usually fly.
Last edited by carcynic; Sep 29, 2014 at 05:38 PM.
Sep 08, 2014, 08:52 PM
Fun until flying robots attack
carcynic's Avatar
Thread OP
Still in Work:

Flight Test:

On-Board video from a casual Sunday flight can be seen here:
EMAX 2204/2300KV Motor Test Demo Flight (6 min 7 sec)


Flight Times:

I performed an indoor flight duration test...

-- Conditions of Test:

-- Turnigy Nanotech 1.5 (1500mAH) 3S Battery
-- Many Flights on it, and very slightly starting to puff
-- Charged to 12.6V, but the charger had not beeped when I pulled it off charge.
It is likely that it was only a few mAH from a full charge.
-- FPV Video Transmitter Unplugged (The VTx draws about 300mA)
-- MinimOSD board still powered (draws only a few mA)
-- 3 Blade 5040 semi-carbon props.
-- Leisurely indoor flying... A few passes... climbs to the ceiling... getting out of the way
of kids playing basketball (What a stupid thing to use a basketball court for !), etc... Slightly more usage than just a hover.
-- No significant time spent in ground effect.
-- Landed with in a few seconds of the beeper (set to 3.3V/Cell) going off.
(In other words, not straining or stretching the battery.)

And the answer is...

7 minutes, 52 seconds.


Competing motors:

EMAX offered me these motors to test. The did not offer me a bribe, or give me the motors in return for false propaganda. I believe they truly wanted my opinion and my feed back to improve them.

For this reason, I will mention some of the competition (or more correctly, point out that there is none.)

As mentioned in the 1st of these posts, I like the removable prop mount on the DYS 1806's. I also like the fact that DYS includes bullet connectors. If someone were going around handing out free motors (Oh... Wait...) I would frankly rather have the DYS 1806's over the EMAX 1804's or 1806's.

However, there is no similar DYS 2204 or equivalent. The DYS 2208 are a larger, heavier motor, and would get you in the same situation as the Angel 2208's I had previously.

Further more, EMAX (or at least some of their retailers will / can simply include bullet connectors and heat shrink.


Conclusion:

I will say that that my BlackFish 250 is a totally different quad with these motors. It's not that the previous motors were bad or of poor quality, it is just that Angel 2208/2600KV's are not right for a 250 Quadcopter.

The EMAX 2204's are far better suited for a high performance 250 Proximity Flyer/Racer than the Angel 2208's.

With the EMAX 2204's, it still has more than adequate "Punch" (Rate of Climb), but is far more stable, and I am getting far more flight time.

I will say that even the 2204's are pretty powerful for a 250 Quad. I would not recommend them for those just getting started in Proximity Flying. Start off with some of the 1804 or 1806 motors.

If you have some FPV prox flying stick time, and you are ready for aero mode flying, Full Fast Forward passes, or racing --- Yeah -- These motors can certainly do it.
Last edited by carcynic; Sep 26, 2014 at 05:10 PM.


Quick Reply
Message:
Thread Tools