A2212/5T 2700 Kv motor budget power upgrade or buyer beware?

Hi Everyone -

I had the thrust stand busy yesterday doing some more testing with the inexpensive A2212/5T 2700 Kv motor with the 6x3E sport prop from RC Timer and the Turnigy AE-45A ESC.

I am doing some more testing with this motor and setup as a possible inexpensive power upgrade from the 2212/6 2200 Kv motor for those folks who don't perhaps want to play around with quad racing motors that can get a bit more pricey and amp hungry.

I will get to the specifics of the testing towards the end, or if you don't want to wait, you can check out my motor test spreadsheet here.  Please scroll along the bottom to find the tab for this motor, it is over to the right of the spreadsheet.😀  Also, if you watch rcplanepirate's YouTube channel, he has done all kinds of testing and has shot three videos on testing one of these motors he bought from EBay.

I have run these motors in several different planes for a couple of years now and certainly you get what you pay for, but I have had some pretty good performance from most of the ones I bought and have run them pretty hard on 6x4 APC electric props (knock offs from Hobby King) and the 6x4 APC gas prop.  If you pick a couple up, my advice would be to be prepared that your motors might not last terribly long depending on how you run them, quality control is not a big strength of motors that you can get for $5-7 USD😏

The link above for this motor is from GearBest, I have also purchased them from a couple of different vendors from EBay.  GearBest just raised the price to $7.01 USD which is the price at the time of writing this post.  There are several vendors on EBay that sell this motor, I just found this one that sells the motor for $5.16 USD.

The worst experience I have had with this motor were two that I bought from Banggood over a year ago.  The two motors I got from Banggood were not usable, even with a 6x3 prop, they both pulled over 40A and ran exceptionally hot.   Here is the link to the Banggood motor, they want $7.59 USD for their version😕

In all honesty, it is very difficult to know the amp limits on this motor.  Reading specs from this vendor on EBay, they give it a very low amp rating.  Here are their specs copied and pasted in.

Model No.: A2212/5T 2700KV
Weight: 50g
Motor Dimensions: 27.7 * 26.3mm
Shaft Size: 3.17 * 37mm
Battery Operating: 2-3 LiPo
Idle Current: 1.8A
Load Current: 18.5A
Power (Watt): 240
ESC (A): 30A. 20A
Ri (MΩ): 0.14
Peak Amps: 14-22 A

I have a bit of a hard time believing this motor is rated that low, unless it was run on 2S or with a very small, low pitch prop on 3S where you would get very limited thrust.  I think I have also read somewhere it is a 25A motor, again I think a bit low.  However, all of the motors I have run do run warmer/hotter than other higher quality motors.  One of the areas that most manufacturers will "cheap out" on is the bearings which can cause the motor to work harder and rather than producing more power, the motor produces heat.

Here are some comparison pictures.  The motor on the left was run for almost 300 flights using the 6x4 APC electric prop.  This motor was consistently pulling 35A on a static test.  It has now pretty much reached the end of it's productive life as the bearings are starting to go😢  Hopefully you can see that the top has become discolored, much lighter than the new one on the right.

In the next two pictures, I tried to get shots of the wires, the wires on the used motor are darker indicating they have had some pretty high temps running through them.  The new one of course has very nice, shiny wires.

Another thing to look for when a motor is starting to run rough or the bearings are going is to pull gently on the bell of the motor, looking for a gap where my thumb is pointing below.  In the old motor, I can pull the bell so that this gap is about 1mm, on the new motor, the bell barely moves.

So to answer the question, can you run this motor on a 6x4 prop?  Yes, you can, but you need to be aware that you are probably pushing the motor pretty hard and depending on whether you got a good motor or a bad motor will determine it's longevity.  I suppose 300 flights from a $5 motor is not a bad result (about $.02 per flight😉), I have certainly had more expensive motors last less time than that😒

I did run this motor with the 6x3E sport prop in the past, also available from HobbyKing as 6x3 TGS and Banggood as 6x3 KMP and it ran very well, I just preferred at the time the feel and performance of the 6x4 APCE prop.  So now that I have an actual thrust stand that is far more accurate than my previous crude setup, I decided to do some more bench test comparison.  The results were actually quite good.  I first tested with the Turnigy Plush 40A ESC with timing at low as this is the ESC I have been using all along when flying with this motor.  Here are the results with the 6x3E sport prop.

50% throttle - 13.1A/158.8W producing 540 gr/19 oz of thrust;

100% throttle - 28.2A/328.1W producing 995 gr/35.1 oz of thrust.

So these results are quite good and very efficient for that much power.  Compared to the best setup I have found with the 2212/6 2200 kv motor, it is about 80 gr more thrust at mid throttle and 45 gr more at full throttle, so certainly a boost in power, especially at mid range.

So since I have been seeing such great results with the Turnigy AE-45A ESC with custom settings of 22.5 degrees timing and 24 KHz PWM frequency, I gave that a try as well with three different props.  Here are the results.

6x3E sport prop

50% throttle - 14.8A/182.2W producing 586 gr/20.7 oz of thrust;

100% throttle - 30.2A/348.3W producing 1045 gr/36.9 oz of thrust.

6x4 APCE (Hobby King knockoff)

50% throttle - 14.3A/173.0W producing 530 gr/18.7 oz of thrust;

100% throttle - 34A/395.5 producing 1010 gr/35.6 oz of thrust.

6x4 APC gas

50% throttle - 14.6A/176.2W producing 555 gr/19.6 oz of thrust;

100% throttle - 36.5A/402.3W producing 920 gr/32.5 oz of thrust.

So I was quite surprised at how low the top end thrust was with the 6x4 APC gas prop considering it is better than that with the Turnigy Plush on factory default although the AE-45 does give slightly better results at mid throttle.

I was quite impressed with the thrust and efficiency with the 6x3E sport prop with the AE-45 ESC, so I will have to give that a try at the field and compare it to the 6x4 APCE since if I am trying to find a "budget" power upgrade, these props are much less expensive and available than the 6x4 APC gas prop.

So next up some field testing with this motor, the AE-45A ESC and the 6x3E sport and 6x4 APCE props😀

Park Jet noise...the "other" sound of freedom😎

Cheers,

Scott