This review is about the small brushless Racerstar BR1103B motors that were kindly sent to me by Sandra from Banggood for a review.

You can buy them here: https://goo.gl/87uhXS 

Weight: 3.63g
Shaft: 1.5mm
Kv rating: 10000KV
Voltage: 3.7-11.1V (1-3s LiPo)



I have used their older version (RS1103) on my Minimalist 112 frame and they had only one flaw - if you used props with mounting hole too tight, by forcing it to fit the prop shaft sometimes pushed it inside the bell making it loose. This should not be the issue here as the shaft is held by more aluminum and glue. 



The motor comes packed in a small box, together with 4 screws that are… too small to mount it on a frame… Luckily I have a ton of M2 screws left from my old DYS 1806 motors and they fit perfectly. Actually… I am very happy they changed the size of the mounting holes as M2 screws seem to hold it really tight on the frame.



The top of the bell has a changed design - now it also accepts props that are secured using M2 screws.

Tips:

If you want to use press fit props - get a 1.45mm drill bit to drill larger holes in prop hubs. This way you will be able to use propellers from your old toy quads, but it also helps with fitting props that were meant to be used on a 1.5mm shaft. For example, the Eachine 65mm prop requires a lot of force to fit it, drilling it to 1.45mm makes it easier but it still doesn’t fall off during flight.

There are very thin wires used here, and by nature, they are also very brittle - its a good idea to first solder on a very short silicone coated wire (28-30AWG is perfect) to the ESC pad and solder the motor wire into it. This will act as a “pigtail” to avoid them breaking in crashes or trough vibrations. You can also use a bit of hot glue on the pads if you prefer to.

Thrust tests:

I have tested this motor on RCbenchmark 1520 thrust stand with a custom micro motor mount. The thrust stand was kindly provided by Oscar. Thanks mate!
Power source:
1S: single cell from SLS 1300mah 45/90C
2S: Giant Power 50C 350mah, 4 packs in parallel
3S: SLS 850mah 45C

Propellers used in this test are:

• Racerstar 2035 quadblades and biblades (two blades cut off)
  
• “Brushed” Ladybird (and cut to 2”), Hubsan H107L and Eachine e10 props
  
• Gemfan 3025 biblade full and cut to 2”
  
• Racerstar 2530 R-DD65 65mm biblade full and cut-down to 2”
  
• Eachine CG022 props (first toy quad) full and cut to 2” and also 1.5” for a 3s test.
  

See thrust test results below:







Download thrust table here: https://1drv.ms/x/s!AjPcddmb6KaegQDAQuIpz-0RerGC 

Rows marked as “hot” mean that motor was unpleasant to the touch.

First thing I have noticed is that 2035 quadblades are drawing the largest current. It is way better to use them as biblades after getting two blades cut off - the thrust remains the same, but they become a lot more efficient.

Gemfan 3025 biblades are way too heavy - I have felt the scent of burnt motor after 3 seconds of test. It was too hot to touch, luckily it is still working. After cutting the blade to 2”, it is still pretty heavy, but usable.

Looking at the rest of the test it becomes apparent that this motor performs the best with very light 2” blades, while the 65mm Racerstar 2530 R-DD65 may be considered a good, but very heavy propeller for it.

The motor should be used on the lightest 2s builds possible.

I have also ran this test for 2035 cut on 3s but it got too hot very quickly despite the fact that it was not charged completely.. I do not recommend using this motor with those packs, I just don’t see the point of it - you increase the mass by mounting a heavier pack just to receive a similar amount of thrust.

Pros:

• Can mount props with M2 screws or by a press-fit
  
• Prop shaft is held by the bell better than in previous version
  

Cons:

• Motor mounting screws delivered in kit are too small, should be M2
  

Reviews of the remaining hardware for the build:

• 12A 4in1 Racerstar ESC
  
• Mini Acro F4 flight controller
  

Incoming:

• 85mm build
  

Konrad

Nice review! The hubsan props look pretty good for thrust and efficiency. What size is that, and did you have to drill and press fit those?

Thanks! Hubsans are about 55mm and yes, they need drilling.

Thanks for the review Konrad, very helpful information indeed!

I am running the BR1103 on my 100mm micro with the Racerstar 2025 quadblades props, and the motors are hot to the touch after a couple minutes of intermittent hovering. Do you think it would help if I were to break off 2 of the blades as you did with the RS2035 during your tests?

(26-Jul-2017, 10:48 AM)domtkho Wrote: Thanks for the review Konrad, very helpful information indeed!

I am running the BR1103 on my 100mm micro with the Racerstar 2025 quadblades props, and the motors are hot to the touch after a couple minutes of intermittent hovering. Do you think it would help if I were to break off 2 of the blades as you did with the RS2035 during your tests?

Generally, those motors seem to like very light blades, so seems like removing those blades will help. But your motors can also be hot due to tune or bad filtering. Hovering shouldnt be an issue unless your quad is really heavy and has to compensate by pushing more power into the motors.

I find it very odd that the 2035 quadblades cut to 2 blades produce the same thrust.
It just feels off... is it the
Any insight in why this should make more sense to me? Is it purely the weight which they motor just cant handle?

(27-Jul-2017, 10:47 AM)Fint Wrote: I find it very odd that the 2035 quadblades cut to 2 blades produce the same thrust.
It just feels off... is it the
Any insight in why this should make more sense to me? Is it purely the weight which they motor just cant handle?

Yeah, in this case it is probably caused by lack of torque. But generally, biblade props are considered faster than triblades, while triblades provide more "grip"

Great review KonradS!
I've been wanting a micro brushless setup pretty bad for a while now... You're making it worse.

What are you planning to build? There are some spintech 1106 8000kv motors that I would.... Ah I was supposed not to make it worse?

(30-Jul-2017, 07:23 AM)KonradS Wrote: What are you planning to build? There are some spintech 1106 8000kv motors that I would.... Ah I was supposed not to make it worse?

I was thinking something in the 130 size or smallest I can find that will mount 30.5mm FC. I have a FC/Rx combo from FrSky I want to try with it.
Have to get through vacation first though.

Then I'll just leave it here
https://www.rcgroups.com/forums/showthre...roductions

(30-Jul-2017, 01:44 PM)KonradS Wrote: Then I'll just leave it here
https://www.rcgroups.com/forums/showthre...roductions

That is exactly what I have been looking for! Thank you very much Konrad.....

Way lighter than some of the others I have seen that will hold a standard FC.
I like the way this QQX-130 looks but she's heavy as   compared to the minimalist lol. Trying... trying not to research too much as I tend to buy when I shouldn't if I do.

(26-Jul-2017, 12:14 PM)KonradS Wrote: Generally, those motors seem to like very light blades, so seems like removing those blades will help. But your motors can also be hot due to tune or bad filtering. Hovering shouldnt be an issue unless your quad is really heavy and has to compensate by pushing more power into the motors.

I am using the Aurora 90 frame which I believe is on the heavy side. I went ahead and removed 2 blades from the 2035 props, and you are right I barely noticed any difference in terms of thrust, it did seem a little less noisy, and even the motors are still relatively warm they seem to be slightly cooler than before (could just be my imagination though haha)

Hi folks, late update

I was testing if I can use them on a 1s quad despite their "low" kv - 1s thrust table added.