I’ve had an opportunity to take a look at the 9$ motors being sold by FPV Model – > RobotDog RD2206 2500kv.
What is so special with those motors? Price for sure. It is around £6-7 which is half price of the cheapest motors in UK shops.
Stator diameter: 22mm
Stator heigh: 5mm
Weight with long wires: 28g
At close look
RobotDog motors despite low price have (surprisingly) premium feel. Shaft is held by a C-clip. Material feels solid. Bell has thick cooling fins and coils are winded nicely. Motor feels smooth when spun by hand.
They come with 11cm length wires.
Magnets don’t have too much resistance and it would be fair to compare their resistance to Lumenier RX2206 2350kv which were my favourite smooth motors for a long time.
There is no vertical play in the bell at all.
I have tested motors on my 5” „Steele” Alien
- KISS 32A Esc
- KISS FC V2
- ImmersionRC Tramp VTX
- RunCam Swift V2
- Crossfire Micro RX V2
- Turnigy Graphene 4S 1300mah
- HQ 5×4.5×2
After flight impressions
I flew over my usual flying spot – open space fields. Motors performed very well. They were very very smooth. There was no shakes or oscillations during the flight (I had some on the same setup with LeDrib motors for instance). Low end of the throttle had plenty power. On the other hand when punched (above 60% throttle) motors were not that much powerful. It comes down to the stator heigh and 5mm is not enough for motors to be very powerful. My flight was snappy enough but was lacking that extra kick you get with 7mm stator motors.
I had some bounce backs on that setup and that definitely needs tuning to get rid of.
I was getting almost 4 minutes of pretty snappy cruise and acro flying. When I pushed more throttle battery lasted me 2 minutes.
On average I have seen between 13-17amps and even 30 when punched.
My flight video:
- Price! Only 9.99$ (£7.5) which is around half of what motors usually cost
- Low weight
- Excellent build quality
- Very smooth when spun by hand and in the air
- Stator could have been taller to give more of top end speed
- Mine came without the bolts for some reason
I didn’t know what to expect from motor as cheap as this but after the test flight I was positively surprised. Very smooth performance and great efficiency.
I can’t comment on durability at this stage though. Will update this post after more testing.
RobotDog motors can be recommended for those who want to build on budget as well as for new pilots just getting into the hobby. They are cheap enough to replace when needed. On the other hand I wish they could have been made with a taller stator and somehow low price or at least at similar level. That would make them even better choice.