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Old Apr 11, 2007, 12:21 PM
Detail Freak
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Harbor City, CA
Joined Oct 2003
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Help!
Airtronics 94761z-Problems?

Hi, All-

I'm assembling one of the current go-fast slope racing molded gliders, and decided to give these Airtronics 94761z's a try. I really like the fact that they are thinner, and all-around smaller than the JR DS368's that I've been using. They fit better in the thin sailplane wings.

Anyway, I had something new happen to me last night. While I was trial fitting the flap linkages to the plane and servo, I had the 761 start buzzing lightly, and it got a bit warm. I thought it might have been binding, so I unplugged it. I know that binding is BAD for digi's, and any servo for that matter. The linkage was only binding for maybe 10 seconds, more likely 5 seconds.
I checked things out, and did a bit of filing in the linkages tunnel to help clearances. Re-assembled, repowered up. Still the buzzing, and warming....

Now, the servo "sticks" in one position sometimes, sometimes it doesn't...
I'm thinking of sending it in to Airtronics, but I'm not sure if it's a warranty issue, or I damaged it...

Basically, I don't want to glue any of these servos into my wings, if they are going to be that unreliable...

Is this a "FLUKE" bad servo, or have others had similar experiences with these servos?

I am running a 4 cell pack, and the servo was only held in place by my finger when this happened. I'm using an EVO Tx, and have the travels turned up almost max.

Thanks,
Target
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Old Apr 13, 2007, 04:30 PM
Detail Freak
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Harbor City, CA
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Bump.

T
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Old Apr 13, 2007, 04:44 PM
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Sacramento, CA
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T --

I have six of these in my AII running the whole ball of wax and, other than a slight sticking problem in one of my flaps that I attribute to tunnel clearance problems, they have been really good servos for me. Super fast, and really solid (landed pretty hard with the flaps down for friction to save a cliffside slide and they both held w/out damage).

Tom's got a way-cool way of mounting them that doesn't require glue, on his site, here.

None of them get warm but there is a buzz when max deflection is exceeded.

Hope this helps. Sounds like a bad apple to me.

Kurt
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Old Apr 13, 2007, 04:46 PM
F3X
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Costa Mesa, CA USA
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So Target is this for your new ARIS? Send it back in because you sure don't want a sticky wings servo in your new ARIS. Airtronics is out of stock right now so if you want you could use a JR DS368 for the ARIS flap and the 761 for the ARIS aileron.

And I think of all the Airtronics 761's I have sold maybe 2 had issues out of 100's.
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Old Apr 13, 2007, 05:00 PM
Detail Freak
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Harbor City, CA
Joined Oct 2003
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It's for the new ARIS , Tom.
I already have one coming as a replacement, if I get it Saturday, I can be flying (The new ARIS )Sunday...If the wind isn't NE...

I think the servo didn't like it's super short period of binding...I didn't even have it glued in, just held down with my finger! Total bind time, about 10 seconds, maybe; probably LESS!

Anyway, just wanted to make sure it was a fluke before they get mounted. Into the new ARIS .

Thanks.

Let me know if you get up this way this weekend.

Target
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Old Apr 13, 2007, 05:06 PM
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Shropshire
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Quote:
Originally Posted by target
It's for the new ARIS , Tom.
I already have one coming as a replacement, if I get it Saturday, I can be flying (The new ARIS )Sunday...If the wind isn't NE...

I think the servo didn't like it's super short period of binding...I didn't even have it glued in, just held down with my finger! Total bind time, about 10 seconds, maybe; probably LESS!

Anyway, just wanted to make sure it was a fluke before they get mounted. Into the new ARIS .

Thanks.

Let me know if you get up this way this weekend.

Target
Im sure one of the F3F regulars in the UK has had a similar problem with the Sanwa equivilent ...dont think it was anything to do with binding ...Knewt probably knows the full story


Andy
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Old Apr 13, 2007, 05:24 PM
RC LIFER
santa rosa California
Joined Aug 2005
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I think it IS the binding.

I recently built a plane, as i was programming the flaps I thought were stopping at the end-points, but it actually was both flaps reaching their limits identically.

Needlees to say, the servos got stalled out for a couple seconds at a time, a couple times before I caught it, and Both servos were very, Very warm. They still function so I consider myself lucky.
I estimate the servos were stalled for a total of Maybe 10 seconds, at 2 second intervals over the period of a few minutes (Checking end points), and i was Very surprised to see how hot they got so quickly. These were JR368's

A solid 5 or 10 second continuous stall is all it takes to burn a good digi up.

That said, I have also seen servos malfunction prematurally.
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Old Apr 13, 2007, 05:26 PM
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North Hills
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While I was assembling (not building ) my new HADES 2, I had one 94761 that seemed to hang up and got real warm; linkages were not attatched. I unpluged it, let it cool, moved it manually and tried it again. Second time around it was fine. I kept it powered up throughout the entire set up (and for a couple hours watching TV) and then installed it using a servo frame. I've flown it a bunch since then, and haven't noticed any problems.

FWIW, I called Tom and he suggested I send it back to him for replacement. I didn't, since A) I was using a servo frame so it was easily removable, and B) I wanted to test fly it the next day.

BTW, I saw Target's ARIS in San Diego and I must say, it's a pretty fine ARIS.

Pete
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Old Apr 13, 2007, 05:58 PM
Detail Freak
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Harbor City, CA
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Gee Pete, I really didn't know you cared about my ARIS so much

T

I'll just be sending that one to Airtronics, and see what they say. If course, I have already cut some of the lugs off...
Anyway, as soon as the one comes in the mail, I'm covered.
I woulda bought them from Tom, but he was out playin' around!

T
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Old Apr 13, 2007, 06:37 PM
F3X
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Costa Mesa, CA USA
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Shoot I would have sold you some but Airtronics are out of 761's ask Brandon So this weekend I will put DS368's in his Furio , Good to hear the ARIS will fly soon!
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Old Apr 13, 2007, 08:30 PM
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Los Angeles, Ca
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Target: I have 6 in the Skorp and 4 in the Aris and some others scattered about and I did run across 1 that developed some terminal disease during plane setup. Just plain stopped moving. Airtronics readily replaced it. Once in the planes, everyone has worked fine, and even my landing attempts have failed to bust a gear.
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Old Apr 13, 2007, 08:39 PM
Detail Freak
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Harbor City, CA
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Thanks, Bill. I will forge ahead, just as soon a I replace the front brake pads on my commuter.
Dang it!

T
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Old Apr 13, 2007, 09:05 PM
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san francisco
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no problems here

i have them in a couple of gliders both 4 and 5 cells no problem thus far..

val
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Old Apr 13, 2007, 10:23 PM
slope'n the Colombian Andes
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Colombia, Antioquia, Girardota
Joined Mar 2001
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Quote:
Originally Posted by gingin
i have them in a couple of gliders both 4 and 5 cells no problem thus far..

val
Same here... absolutely no problems to report. Sounds like a fluke, and it appears you already have sent it in for replacement?

Dieter Mahlein, ShredAir
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Old Apr 13, 2007, 10:43 PM
Detail Freak
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Harbor City, CA
Joined Oct 2003
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It's still on my bench, Dieter.

Thanks to ALL of the guys that chimed in.
I had the mods move this thread (the first post at least) from the radio forum, to here. You'd think I'd get SOME feedback there...
I guess they are all using BIG servos!

T
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