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I would never use a Hitec servo of any kind for the
elevator. I use them in other applications but never the
elevator.
Walter
At 09:24 AM 2/8/05
-0800, Albert E. Wedworth wrote:
Hi
All
I'm building a HM
Ventus 2ax 5 m model sailplane.
I've used Hitec digi servos thought.
HS-5245MG digi Mini & HS 5125
MG Digi thin wing servos.
What I've noticed is they burn out very easily..
What's up !!!!
I haven't gotten my plane in the
air yet and I've burned up 5 of the servos already!!!!!
What burned out so
far...
1. rudder
servo; on a pull pull system HS-5245 MG Digi
( to tight ) my fault... Non Digi
now.
1.Tip aileron
HS-5245 MG Digi servo.
2. Flap servos HS-5125 Thin Wing Digi servo.
1. Spoiler servo HS-5245 MG Digi
servo.
None of my
surface's are tight!
5
cell battery pack.
Should I be concerned???
Is this normal???
Could it be too much throw?
I like that Hitec
replaces then without a questions, But.....
I've never had this
happen with non Digi servo before..
So let me know if this
is happing to others out there.
Cheers
AL
Albert E. Wedworth ( AL
)
Hi Al,
I've had quite the opposite
experience with the Hitec HS-5245 servos. I've got three electric helis in the
".38 size" with 550mm blades running HS-5245s in eCCPM mode and they have
worked flawlessly. I've also used them in gliders on flaps and elevators with
perfect centering and no drift due to temperature excursions. They are not
quite to the quality level of the JR DS3421, but they are pretty good,
nonetheless.
What gauge of wire are you using for the power and ground
runs to these servos? Insufficient wire gauge or lousy connections/connectors
can yield significant IR losses (this is part of Ohm's law with I=current and
R=Resistance) resulting in major voltage drops at the servos. Many analog
servos will continue to work during a major voltage drop, but with much lower
torque and slower transit speed, while the digital servo's internal
microcontroller will often reset during such a voltage drop.
You can
chase down the problem by monitoring the voltage AT THE SERVO while running
the surfaces through their paces. Alternatively, you can attach a battery
minder such at SkyKing's Lost Model Locator (http://www.skykingrcproducts.com/accessories/lostmodel/lost_rc_model_alarm.html)
in line with the servo. The finder is fast enough to respond quickly with a
low voltage condition (I should know, I designed the product for SkyKing). A
quick beep or prolonged beep, will indicate a voltage drop due to the IR loss.
I also know where to get some really dependable wiring harnesses built to
commercial specs, with commercial equipment ;-), but you already knew
that.....
Remember that the instantaneous current demands seen with a
digital servos are often much higher than their analog counterparts, thus the
IR losses become even more apparent with digital servos. There is no free
lunch.....
Tom Hoopes -
([EMAIL PROTECTED])
------
Hoopes Designs -----
"Taking the hassle out of wing wiring
harnesses"
<http://www.hoopesdesigns.com>
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