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Old Jul 05, 2011, 01:22 PM
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"BrownOut Reboot" with cheap servos

Hi,
I have experienced "BrownOut Reboot"with some 9gr very cheap servos on my 1meter 3D katana (lipo 3s 2200, both AR6100/JR receivers,
BL 36-16M 1050 rpm*V, ESC 30 A).
Servos remain locked in a end position (fortunately only rudder!!).

I'm intentioned to replace them with the Corona/HobbyKing 929MG Metal Gear Servo 2.2kg/ 12.5g/ 0.10sec


Somebody tested this servo with spektrum/JR radio and experienced with "BrownOut Reboot"?

thanks

john
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Old Jul 05, 2011, 01:49 PM
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But what is the capacity of your BEC?
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Old Jul 05, 2011, 02:04 PM
"Unnecessary Necessity"
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If it is the HXT-900, they are known for very high peak current and 3 of them on 3 cells would overload most bec:
http://www.bhabbott.net.nz/Servo.html
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Old Jul 05, 2011, 05:46 PM
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Well, part of the reason the HXT900 has high peak current is that they are fast! Comparing the HXT900 to the crappy HS-55 (as done in the linked page) is unfair. The HXT900 is as fast as the HS-65HB and has almost the same torque. The HS-65 is a better servo - no discussion - but it is also more than 5 times as expensive!

I have tried the Coronas, but are not impressed. They generate some nasty noise pulses, which may disturb other servos or the receiver. As other posters mention your problem is most likely an underrated BEC.
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Old Jul 06, 2011, 06:25 AM
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I have some 30A esc with switching BEC's only rated for .7A or 700MAH, yes thats right .7A . If your servo are have a high amp draw rating, would not be surprised you have BEC failures causing your receiver to reboot.

It is most of the time if not all of the time a power issue.
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Old Jul 06, 2011, 10:57 AM
"Unnecessary Necessity"
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Quote:
Originally Posted by Tomve View Post
Well, part of the reason the HXT900 has high peak current is that they are fast! Comparing the HXT900 to the crappy HS-55 (as done in the linked page) is unfair. The HXT900 is as fast as the HS-65HB and has almost the same torque. The HS-65 is a better servo - no discussion - but it is also more than 5 times as expensive!

I have tried the Coronas, but are not impressed. They generate some nasty noise pulses, which may disturb other servos or the receiver. As other posters mention your problem is most likely an underrated BEC.
Being fast become irrelevant when the Rx goes into re-boot, the HXT-900 is cheap and perform poorly as for many other things "you get what you pay for"
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Old Jul 06, 2011, 11:23 AM
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Quote:
Originally Posted by coriolan View Post
Being fast become irrelevant when the Rx goes into re-boot, the HXT-900 is cheap and perform poorly as for many other things "you get what you pay for"
No, being fast may be a requirement. Instead of solving the problem by using inadequately slow servos for a 3D plane, the solution to avoid brown-outs is very likely to use a sufficiently rated BEC instead.

Yes, the HXT900 is very cheap, but how does it perform poorly?

Your saying is wrong: "you pay for what you get (but seldom get what you pay for)"
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Old Jul 06, 2011, 11:24 AM
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Quote:
Originally Posted by coriolan View Post
Being fast become irrelevant when the Rx goes into re-boot, the HXT-900 is cheap and perform poorly as for many other things "you get what you pay for"
I've had good performance from the HTX900 servos and no problems running 3 servos on 3s pack with 40A ESC (linear BEC unknown rating). I should note that the flight loads are fairly light.

I would say you get quite a lot in this servo for the little you pay.
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Old Jul 06, 2011, 01:27 PM
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Servos are: DYS 0206

*Weight:9g
*Size: 23.0 x 12.0x 21.5mm
*Operating Speed : 0.12sec/60o
*Stall Torque : 1.5 kg/cm
*Operating Voltage:4.80-6 Volts

I used also the MG version with the same poor results.

I replaced also the ESCs: first I used a HW 30A (5V, 2A BEC) then replaced with a more expensive XREG 40 (40A, 5V 3A BEC) but still the same problems.

When I compared these servos with others more expensive (e.g. Hitec, Corona, Henge) I noticed(without power supply) when trying moving them with the hand that they were not smooth to move.
I thought this could be the reason of BrownOut Reboot due to the high power (current or voltage drained) requested when flying 3D.

john
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Last edited by hot wings; Jul 06, 2011 at 01:28 PM. Reason: .
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Old Jul 06, 2011, 01:52 PM
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The servos must be smooth in the gears! If you can afford it, I can recommend HS-65HBs. If you want to go cheap, you can try the Turnigy MG90S - I use them with great satisfaction in a couple of HK450 helis.

I have bought a couple of Coronas (DS-929, DS-919), but they seem to induce jitter in other servos on the same receiver. I have also tried a Henge 922, but it had some random jitter and would not always come on, when bench tested for brown-out.
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Old Jul 06, 2011, 02:06 PM
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That's the answer I was looking for!

I don't want to have brownout reboot anymore!

I'll try the Turnigy servos MG90S for my HK450 and my 3D airplanes.

What servo did you use in your HK 450 for gyro? I have Henge 922 already purchased to test.

Thanks
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Last edited by hot wings; Jul 06, 2011 at 02:15 PM. Reason: .
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Old Aug 24, 2011, 01:30 PM
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Quote:
Originally Posted by hot wings View Post
Hi,
I have experienced "BrownOut Reboot"with some 9gr very cheap servos on my 1meter 3D katana (lipo 3s 2200, both AR6100/JR receivers,
BL 36-16M 1050 rpm*V, ESC 30 A).
Servos remain locked in a end position (fortunately only rudder!!).

I'm intentioned to replace them with the Corona/HobbyKing 929MG Metal Gear Servo 2.2kg/ 12.5g/ 0.10sec


Somebody tested this servo with spektrum/JR radio and experienced with "BrownOut Reboot"?

thanks

john
Hi guys,

I flew my plane with the brand new Corona/HobbyKing 929MG Metal:
GOOD! GOOD! GOOD!

No brownout anymore!

I had 15 flight in very hot weather conditions and I'm very satisfied.

I have just bought 8 more Corona/HobbyKing 929MG Metal servos for my models and for my just finished F22 EDF70 raptor.
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Old Aug 25, 2011, 05:51 AM
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Originally Posted by hot wings View Post
What servo did you use in your HK 450 for gyro? I have Henge 922 already purchased to test.
I use a Turnigy/MKS DS480 for the tail. This is a very good servo for the money. Smooth, fast and small.
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Old Aug 25, 2011, 06:40 AM
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The Netherlands, EHKD
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6200 with sattelite, 4 ts-9018MG RCtimer servo's, 5A Ubec and still a brown out on my Dx6i.
The DX6i takes about 6 seconds to restart the reciever connection. That is tooooooo long! I bought a Turnigy 9x, Frsky and flashed it to ER9x.
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Old Aug 25, 2011, 12:43 PM
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Originally Posted by Solex_nl View Post
6200 with sattelite, 4 ts-9018MG RCtimer servo's, 5A Ubec and still a brown out on my Dx6i.
The DX6i takes about 6 seconds to restart the reciever connection. That is tooooooo long! I bought a Turnigy 9x, Frsky and flashed it to ER9x.
Hi,
I checked your ts-9018MG and it has only 1,5 kgxcm torque.
My previous servos were basic and similar to yours.
I suggest you to use at least 2.2 kgxcm torque servos in order to avoid stall at end position and very high power consumption (increasing in that position).
They say that ts-9018MG is comparable to Corona but I do not think it!
Buy Corona genuine servos!
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