2212/6, 28A Brushless Motor

Watt meter and tachometer readings for motors with different props. Each motor gets a separate topic.

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2212/6, 28A Brushless Motor

Postby hyperion1 » Wed Apr 13, 2011 8:01 pm

Hi all, i have 5 of these and have only recently found somewhere to fly at full pelt. Great, but i've burnt 2 out !

I'm really confused; the data sheet indicates a max of 342 watts. On a 6x4 APC i have been getting anything from 230-290 watts, even the higher figure is still withing the 28 amps.

If i prop down to a 5x5, 5.5x4.5 or a 5.25x4.7 the power is reduced to around 200 watts at around 19A and there is a signicant loss of thrust.

Is this common to get such wide ranging outputs between individual motors and why will this 28A rated motor not take a 6x4 with confidence? With a prop in the 5's i have to start thinking if this motor works for me?

Has anyone tried any of the Keda alternatives that Giant Shark sell?

Thanks in anticipation, Hyperion 1
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Re: 2212/6, 28A Brushless Motor

Postby hyperion1 » Thu Apr 14, 2011 8:59 am

Thanks Elmuchacho, that is the motor.

I know Giant shark recommend the 5.25x4.7, i don't know for how long this has been the case.

All these motors seem to have theier origins in the 2212/06 offered by Grayson in USA for the parkflyer foamies and 6x4 was the recommended prop. This seems to have changed over the last 12 months or so to the one recommended above.

On a 6x4 the motor is strong, but will not last, on anything less, it does, for me disppoint. As you say you get what you pay for.

Thanks again for your explanation

Hyperion1
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Re: 2212/6, 28A Brushless Motor

Postby Keith England » Thu Apr 14, 2011 2:01 pm

There is another piece to this that you are not thinking through as well.

That motor has a fairly poor maximum efficiency to start with but it states 14-22 Amps. Watts doesn't come into it; motors are defined by amps not watts - for example a motor that is claimed to be 630W and means 30Amps on a 6S pack is absolutely not capable of delivering 630W as 60Amps on a 3S pack - it will still be limited to 30Amps and become a 315W motor - I personally think any manufacturer that sells its motors specified only in watts is an idiot!

Therefore if you consistantly run it at more than 22 Amps its going to be fairly awful! If that motor is 72% efficient at 22 Amps it will be nearer 50% efficient at 28 Amps. Not only will it get a lot hotter but you are throwing a whole chunk of battery (and therefore both output power and duration) away as heat. If you want to run a motor at 28Amps buy a motor that will take 28Amps while still in its max efficiency range - oh, and it will be heavier, the weight of a motor is proportional to the current it can safely take. To an extent you can get a motor to take a higher current for the same weight by less turns of thicker wire - which automatically means a higher kV. However higher kV means higher RPM means smaller prop means less efficiency and thrust - it only really works well if geared - hence high kV low gearing is the norm in helicopters but for planes it is better to use a heavier motor than the weight of a gearbox! You don't get owt for nowt as they say somewhere up north near the arctic circle!!!

Oh and if you do buy a motor that is actually intended to run a 28Amps efficiently you will actually have more power at the prop (so more speed and or climb) as less of that input power will be wasted.
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Re: 2212/6, 28A Brushless Motor

Postby hyperion1 » Fri Apr 15, 2011 11:22 am

Thanks Keith, your right, that hadn't hit my radar and is really useful stuff, thanks.

I've actually just got 6 Keda motors which go to 420w (oops, that watt word!)as i need to really experiment as i move away from known combinations. i will make afew mistakes no doubt, but that can be a good way to lear.

Interestingly, i put a 6x4 back on my 2212/6's and none ran past 23a, around 235/240 watts. I've decided afew three second full blast bursts are more preferable to propping down to a 5 something.

Thanks, Again, Hyperion1
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Re: 2212/6, 28A Brushless Motor

Postby RobC » Sat Apr 16, 2011 11:07 am

I'm using a 2212/6 motor in my Funjet, running on 3S with a 6*4E TGS prop, I can't remember what the meter reading was but it's survived about a year of use and abuse. Admittedly it doesn't get run flat out all the time as that gets too intense, but it seems as strong now as when I first flew it. I tried the recommended 5.whatever prop, but prefer the 6*4.

It does beg the question, what are you using them in, and do they get enough airflow for cooling?
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Re: 2212/6, 28A Brushless Motor

Postby hyperion1 » Sat Apr 16, 2011 11:39 am

Hi Rob C, They are all in Delta pusher jets, x41 Delta Storm, Deltawatt, Eurofighter, Vantis(modified). Airflow should be o.k.

I think i was to blame in the way i burnt out 2 of them, in that i kept it at full throttle for too long and wasn't allowing any cooling off periods. When i went out a couple of nights ago, i was keeping bursts to afew seconds and once the momentum was there, the 6x4 was doing its job for what i want.

I'm off now to test a Keda 2826/07, 2800kv. With a 5x5 APC prop and Hyperion 1600, 3s 25c it was showing 312w and 29A on my wattmeter. ....I'm going to keep checking it for coolness and take it easy to start with.

Thanks, Hyperion
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Re: 2212/6, 28A Brushless Motor

Postby Ashleylad » Sat Apr 16, 2011 5:50 pm

Generally a burnt out motor is down to overworking it. Too much current. I have several 2212-6 motors all going fine still. A TGS 6x4 prop from memory draws quite a bit less current than it's APC counterpart, yet gives pretty much the same thrust. I always use a 30A esc without problem.

It's always best to do a rough bench test first. I have noticed the KV value can vary slighly and build quality of these motors. If you operate them within the limits they should provide hours of trouble free use.

As for KEDA i would recommend this motor for pusher jets, similar kv to a 2212-6 but lighter and draws less current:-

http://www.giantshark.co.uk/keda-thumrun- ... 03664.html

Here is Dr Kiwi's report on this motor have a look at the tables:-

http://www.rcgroups.com/forums/showthre ... st13790284
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Re: 2212/6, 28A Brushless Motor

Postby hyperion1 » Sat Apr 16, 2011 6:41 pm

Thanks Asleylad and the links are really useful.

I've actually got the motor you recomend but haven't used it yet; thought it could be a good 2212/6 alternative . The more i use the 2212/06 within its limits the more impressed i am and it is cheap !

Cheers, Hyperion
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