HobbyKing 939MG Metal Gear Servo 2.5kg/ 0.14sec / 12.5g
A strong performer with a very smooth movement and good centering.
Excellent for parkflyers or planes up to .40 size (3,500mAh electric).
Operating Voltage: 4.8V / 6.0V
Operating Current: 200mA / 240mA
Operateing speed : 0.14sec.60° / 0.13sec.60°
Stall torque : 2.5kg.cm / 2.7kg.cm
Dead band : ≤5uSec
Operateing speed: 40º/one side pulse traveling 400us
Potentiometer: 2 slider/Direct Drive
Ball bearing: MR85
Connector wire length: 215mm
Operating Temperature Range: -20 °C to +60°C
Spline count: 21
Hmotnost ( g )
Rychlost ( Sec / 60deg )
Točivý moment ( kg) (min . 0,01 kg )
Unit Weight (g):
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Kraftvolles Servo, nur das Gehuse Plastik ist meines Erachtens billig. Schade, dass wre die Top-Wertung geworden. Fr Flchenmodelle guter Durchschnitt.I ordered 4 of them. Tested and all working. I will update my review when I start to use them in my trainer.Compared to what I needed, I got metal gears instead of carbonite gears (my personal opinion: good, some more play, but robust), some more weight (12 instead of 9g), but 11,5 height instead of 9mm, what caused design modifications. on the other side: I paid 75pcnt less, this helps a lot for the efforts needed.Caution Be a little careful which receiver you match these servos with. Even individually they can momentarily draw a current demand large enough to cause a voltage drop sufficient to reboot your receiver, resulting in a couple of seconds brown out whilst it re-initialises. Displays this trait on an orange R620, even with just a single servo moved rapidly and with two different dedicated high rated receiver batteries so not a low rated BEC issue. RX works fine with no drop outs with HXT900s or Turnigy TGY5009M. Others are finding this too with the Corona / Hobbyking 929 / 939 series and are putting capacitors across the RX pins to avoid it, but you might just prefer to get a less spikey servo!
I've been using these for a while now and haven't ever had a problem. I'm one that rarely cuts corners on servos so I fly these on cheap planes and mostly friends planes. They are reliable but you can definitely feel the low resolution. I use Futaba 3156's in most my planes for this size but those cost $45 each and these are just a little over $5. For my precision planes I would never use these they aren't a replacement for my 3156 but they do fine on my scratch build planes.I have bought several of these MG servos in the past and I still use them without any problem at all. Whenever I buy a plane with a non mg servo installed on the elevator, I replace it with this servo. These are strong, have a precise and smooth movement/centering.Cracking little servo...well recommendedI don't know what others say... I use it in every built of mine and I never had any problems!I bought two of these servos and they are very good value for the money - fast, strong, accurate. I bought them on recommendation from fellow modelers - they are proven performers.gPrice and excellent quality.