Contra Rotating BL System 375W

• Overall
• Quality
• Value

Customer Rated

Jun 22, 2014

Very good price for a unique product. First things first - bin the supplied props, way out of balance. Buy some APC tractor/pusher props, I am currently using 12x6 giving just under 40A & 404W (total peak). Then buy some 3mm tool steel, you WILL bend the shaft quite easily. Only a couple of quid.

Finally build something for it (I chose a Westland Wyvern), then go out and enjoy it. I've also purchased the CR50 version of this motor (2x6s 16x10 setup) for the next project.

• Overall
• Quality
• Value

Customer Rated

Jan 21, 2013

The principle works very well. However my front collet had 1/8" / 3.17mm Dia and the shaft 3mm Dia. no wonder it was shaking. After changing to the right one and balancing the prop it runs on 2S. On 3S it is not possible to go to full throttle yet. I ordered a new set of propellers and hope it will work. It seems the currently installed props don't flex alike on the two sides and couse the vibration by passing each other.

• Overall
• Quality
• Value

Customer Rated

Aug 21, 2012

Great motor!

Four of them are working in my

X.8.TAHU.silver shadow coax-copter.

See video:

http://www.youtube.com/watch?v=liZGBab-sQo



:-) Joahnn

• Overall
• Quality
• Value

Customer Rated

May 03, 2012

The props I received with the engine were so unbalanced that it was impossible to run the engine . Huge vibs !!So I balanced the prop by my own with the special device and 2 cutter blades; I was obliged to cut one blade more than 8 mm shorter than the other !!

Then it runned, but with very unsymetrical aero behaviour .

Then , the magnets started to unstick.... This engine must be a very good one , but these troubles makes it impossible to use .

I need a spare rear rotor or a new set of magnets ... but how find them??? It's nowhere on any web page .

• Overall
• Quality
• Value

Customer Rated

May 03, 2012

Hello

As some magnets were unstick, I had to reseal it . But after lots of troubles I need a new rear rotor or a set of new magnets . Who know if it's possible to find these spare parts and where ???

Thank

• Overall
• Quality
• Value

Customer Rated

Mar 31, 2012

I received this engine few days ago.

(order 2004116507 )

The engine itself is a very smart piece of engeenering and works well.

It seems that the constructor has a quick feed back because , all the magnets came well stuck . No magnet failure anymore so.



But the big trouble comes from the props ! The 10x6 " contra one ( closest to the engine ) is unbalanced up to an enormous rate!! '(The other prop - normal rotation - is OK )

It's made of semi rigid platic, and triming the balde to get it balanced drives to shorten the tip of more than 5 mm !!!!!! . No way else, because the prop would tear or bend the axle ! So , I will run with a prop blade with about 6.4 mm shorter than the other ! A very queer look !

And 10x6 is a little strong for the engine . I would prefer 9x5 as proposed before.

Please ,how can I buy a pair of prop : contra and normal, 9x5 , well balanced if possible ?

Thank you for any help to show me where find these props .

Or props made of another stuff : (wood ) because this semi rigid plastic makes it impossible to balance by adding varnish to weigh the lighter blade. A very tricky solution !

• Overall
• Quality
• Value

Customer Rated

Dec 13, 2011

Mine recived with the front propp broken!! otherwise good motor, have it in a fury 3d with lots of power.

79g is a joke, 126grams with propp and spinner!

• Overall
• Quality
• Value

Customer Rated

Oct 16, 2011

I got this motor and it came with 1060 props. these are the same ones sold on HK. 3 spare sets for 3 dollars something. so at least i have spare props if needed. fyi, the RH prop (for the bottom) needs a 7.8 mm dia hole and the normal prop (on top) needs a 5mm hole. i clamped the spare props on a vice and used a metal drill bit to do the job. please be careful to ensure the hole is perpendicular to the hub and that you dont damage the vice or over clamp the prop too tightly. it's done in less than 1 second once you pull the trigger of the drill.

the quality is good. i made a motor mount using 3.5mm plywood with a 29mm dia hole in it for the motor to fit. Use a wood drill bit and a circular file to smooth the edges.

the total vertical thrust it could lift was 1.4 kg using a 3 cell 2500 mah 35C 12.6 v battery. i'm happy with this motor and it really cancels out the torque effect. max amp draw was 14 amps per esc. (28 in total)

for safety, im using 2 x 30 amp turnigy plush escs. one to chn 3 and the other to chn 6. for the one connected to chn 6, i disconnected the red wire on that esc. (if i didn't, i think i would fry my rx? im not sure but can someone explain?)

anyway, i slaved chn 6 to chn 3 on my tx so i can fine tune the motor speeds of both motors and control them simultaneously.

overall, it is a good buy!

• Overall
• Quality
• Value

Customer Rated

Oct 13, 2011

Great motor.

Runs perfectly wihtout any vibration.

I will use it in a special MonoCopter together with a KK BlackBoard.

Look at the video



:-) Jovan

• Overall
• Quality
• Value

Customer Rated

Jul 26, 2011

Out standing motor set, except for the motor shaft. Limp as a noodle. one prop strike, and not only are two props shot, but so is the shaft. Worse yet, HK doesn't sell a replacement shaft. Luckily a new shaft made of hardened DRILL STOCK of proper diameter can be relatively easily fitted.