Initial impressions and bench testing of the Brother Hobby EngineerX 2307 2700 kv motor

Hi Everyone -

I recently completed a bench test session of another quad racing motor I picked up to evaluate, the BrotherHobby EngineerX 2307 2700 kv that I picked up from Banggood.  I picked mine up for $23.99 USD, I notice the regular price from Banggood is $30.67, although at the time of writing this blog post it is on sale for the same price I paid.

I discovered this motor watching EngineerX's YouTube channel, here is his test video of this motor before it was released to the public.

I was very pleased to be able to exchange a few words with him about this new motor.  He mentioned that it might not be for all out speed, but perhaps very good torque.  If you want more details about the "guts" of the motor, please watch his video as he takes it apart and shows the details of the motor.

Mine weighed 34 gr/1.2 oz out of the box, it comes with the standard bolts and a prop nut, the finish is very nice and it spins very smoothly.

With the prop and other hardware attached ready to go in the plane, it weighs 48 gr/1.7 oz which I think is very good for a 2307 motor, it is right there with all the 2306 size motors I have tested thus far.

I started off the bench testing with the 6x4 APC gas prop, you can read all the test numbers on the motor test spreadsheet which also has links to all the components used in the testing.  The thrust numbers were not that great, but the amps numbers were noticeably low, so I tested with the 6x4 KMP props and finally the Gemfan 6045 carbon nylon prop which is what I will field test it with initially on 3S.

Here are the test numbers for this motor on 3S using the GF 6045 prop and the Turnigy AE-45A ESC with custom settings of 22.5 degrees timing and 24 KHz PWM frequency.

50% throttle - 15.7A/192.3W producing 635 gr/22.4 oz of thrust;

100% throttle - 39.4A/451.3W producing 1200 gr/42.3 oz of thrust.

So I am excited to get to the field and test it, my experience has been that with the GF 6045 CN prop, the bench numbers normally carry over well to the field😊

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

Cheers,

Scott

Field test of the EMAX RS2306 2750 kv motor 6x3 EMP prop on 4S - 03 May 2018

Hi Everyone -

Just back from the field ripping some batteries through my red Mig-35B😊

Here is video of one of the flights.  Things happen pretty fast with the extra power, so I might have not been as "chatty" (probably not a bad thing😉) and it was a bit more challenging getting it lined up for some closer passes, but practice will pay off😀

You can read more about the Tattu R-Line 1550 4S 75C batteries I used today at this blog post.

I was pretty impressed with the speed of this plane and how stable it stayed, although since I helped to design and test it, I suppose I'm a bit biased😉

The motor did run pretty warm, but I have certainly felt motors that got a lot warmer and still worked fine.  What really impressed me was how cool the HobbyWing Platinum PRO 40A ESC stayed.  It was warm, but I honestly expected it to be a lot warmer.

In all honesty, I expected it maybe to a bit faster considering it was a 35% increase in thrust over the same prop and motor combo on 3S, but I think the low pitch might have something to do with it.  I suspect when my 5" props show up that have more pitch I might see a bit more speed, but either way, it is very fast and certainly this prop, motor and ESC worked well on 4S.  As I mention in the video, it might take a little patience and discipline to let the motor cool off after a couple of flights on 4S just to keep things running smooth.  

The Tattu 4S batteries had no problem whatsoever delivering the power.  I set my timer for 3 minutes 15 seconds, so the countdown started at about 2:45 and checking the battery shortly after the flight, I was still at around 3.75V per cell which I have learned for long term health is pretty good.  I could probably still safely add about another 15 seconds to the flight in the cooler weather like today (14C/57F), but in the heat of the summer I will probably keep the flights around what I flew today.

So step one of the speed trials is out of the way, I will probably try this out now on my smaller Mig with the 24" wingspan until my "speed build" RC Powers Su-30 V4 is complete.  You can watch more about that project at this playlist on my YouTube channel😀

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

Cheers,

Scott

Tattu R-Line 1550 4S 75C batteries initial impressions and testing

Hi Everyone -

I received a couple of Tattu R-Line 1550 4S 75C batteries in the mail a couple days ago to experiment with some serious speed in my park jets😀

These batteries have a very good reputation from what I have read and watched on YouTube, they were not cheap, but I only bought a couple for some experimentation and serious speed fun!

I went with this small size as I didn't want to pay a big weight penalty, so even though my flights will be short, they should be fast😉  The batteries weigh 186 gr/6.6 oz.  The normal 2200 3S batteries I use weigh 192 gr/6.8 oz, so my planes should still be pretty light to help them be fast. 

I already did some quick testing for a modified RC Powers Su-30 V4 I am building specifically for speed.  Here is a short video I shot discussing this testing.  You can watch more about this special build by going to this playlist on my YouTube channel.

As discussed in the video, the only successful test was with the EMAX RS2306 2750 kv motor using the 6x3 EMP prop and the HobbyWing Platinum PRO 40A ESC with custom settings of 26.25 degrees timing and 8 KHz PWM frequency.  You can see the full details on my motor test spreadsheet, but here are the numbers for the combo I mentioned with this new Tattu 4S battery.

50% throttle - 21.8A/346.5W producing 940 gr/33.2 oz of thrust;

100% throttle - 54.8A/860.2W producing 1630 gr/57.5 oz of thrust.

WOW!  That is a 45% increase in thrust over the best mid range power on 3S and 36% increase at full throttle!😲

Until my 5" props that I have ordered show up, this is the setup I will experiment with.

Here are the 5" props I have ordered based on watching rcplanepirate's video on his testing of the EMAX RS2306 2750 kv motor and his personal recommendations. I pasted this list in from the comments of this video.

Hobby King

HobbyKing 5040 GRP/nylon prop https://hobbyking.com/en_us/glass-fib... Dalprops "Indestructible" Bull Nose 5045 V2 https://hobbyking.com/en_us/dalprop-5... Diatone Bull Nose Plastic Propellers 5 x 4.5 https://hobbyking.com/en_us/diatone-b... Banggood DALPROP 5045 Bullnose PC Propeller https://www.banggood.com/2-Pairs-DALP... Gemfan 5045 5 Inch Propeller Bullnose https://www.banggood.com/4PCS-Bullnos... KINGKONG/LDARC 5040 Propellers https://www.banggood.com/10-Pairs-KIN...

So I am excited to get to the field and start experimenting with these new batteries and this setup in a plane, it is going to be scary fast!😳

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

Cheers,

Scott