I'm finishing a PST Reaction, with all Hitec servos, 123 batt. Specktrum 12020 reciever.
I'm using Hitecs 5685MH for flaps, BUT, twice they have freezed after approx. 5 -8 minutes turned on.
The first ones were sent to Hitec , and they told me the motor was burned ????
Any ideas, or suggestions?

Thanks;

ENT

If you are trying to push the flaps beyond what the hinges will allow then you are straining the servo. When you are setting them up restrict the travel to some small amount using End Points then gradually increase the travel until you get to the mechanical limit or to the position you want. The way a servo works is it keeps trying to get to the commanded position. It does this by increasing the current going to the motor to try to get it to move. Eventually, the servo gets to the point that it cannot take any more current and the motor burns out.

You may also want to install an inline servo current meter - I have one from Hangar 9 (Horizon). This will tell you how much current the servo is drawing - you can then adjust the servo so it is resting and not stalled against the wing, etc. [8D]

I prefer to use analog servos on flaps. You still need to set the end points properly but they are a lot more forgiving if there is slight binding. I usually use Hitec 645MG's onflaps.

Joe

I gave up on Hitech after I lost a 3rd heli from a failed servo.

But regardless.... the above advice is good. Get a meter, and check the draw. You don't want a bind. A current draw could cause a brown-out (reset) on 2.4.

Joe,

That 645MG is exactly what I use on Flaps. Very forgiving, never had a failure. I also use it on nose wheel steering.

Bob

I am a big fan of the 645 as well but do you not think the 5645 holds better for flaps, i.e. you can push back against a 645 (airflow) but difficult to do with a 5645 one reason why I would prefer them.

The HS 985s gives you a bit more at 6.0 v ( 172 oz. ) but also cost about two times more then the HS 645s [:@]

http://www.hitecrcd.com/products/ana.../hs-985mg.html

BUT""" would you have to use a voltage regulator with these
servos? Remember I'm using 123 nano batts.


ENT

Hey Héctor. Just glue the damn things permanently. Save yourself the weight of the servos. The reaction is a floater already, flaps not needed, specially for flying at Sabana Seca.

Saludos doc!
David

<span style="font-family: Arial; font-size: small; ">Hi,</span><div><font face="Arial" size="2">I have put together numerous planes all with Hitec servos except for one prop plane. All my Jets have digital servos, and Hitec with the exception of my SM Mig 29 which also have some JR servos.</font></div><div><font face="Arial" size="2">Always run Life Batteries 6.6 volt.I havenever run a voltage reducer, andnever had a problem. The only time I run a reducer is for my ignition on my gas motors.</font>

Ivan</div>

How easy do your flaps move up and down? My buddy recently purchased one and one wing didn't have the flap completely cut free on the hinge line.

Flaps are designed to change the airfoil curvefor increased lift on takeoff and landings, not to be air brakes like on a jet.Using anymore than the recommended settings just changes their function from creating lift to creating drag.

The flaps have good downward movement, but they have limit upward from top of the wing.
The wing skin is the hinge. Four servos burned, even with limited movement.

ENT

I suspect your voltage is too high for the servos used. I manfactured model servos for 16 yrs (1969-1985) and if any one ran more voltage than specified all warrantees were voided. I recently contacted Hitec about running their servos on 7.2V (2 A123 in series) and got vauge answer. They stated you could run their standard servos on 7.2 but I didn't find out which ones are standard. Personnally I won't run any servo above the specified voltage.

BUT, the ones that got fried stated that could be used with 7.4v's

ENT

I stand corrected. This servo is speced at 7.4volts. Then as suggested before I would look for excess drag causing high current drain.

thanks to all of you guys.

ENT

I've used Hitec 56xx series servos in prop warbirds and for the throttle on giant gas planes and have had a number of them burn out. I wouldn't use them for anything other than a 60 size prop job. The only servos from Hitec that have been trouble free for me are the 7955 and up series...

HiTec servo user for 10 years, even karbonite series. Never a single issue.

+1 Never had a problem, and i have well over 50 servos mostly 5645,7955 and other sizes as well.

Same here, using Hitech servos in my jets for 10+ years on all major flight control surfaces, never a failure. My favorite is the 7955.
Ron

I like and use 7955 also