Thread Tools
Aug 03, 2019, 04:26 PM
Registered User
doug14's Avatar
Thread OP
Discussion

servo glitch at 20% throttle


I posted this in flying giants but decided to try here too. hoping to get as much info as possible before I dump $150 into new servos

so my new issue. 
got curve working smooth. my tune adjusted again with my 16x12 prop.
but as I warmed up I noticed a glitch in ailerion servos. 
it only happens at 19-26% throttle. 
nothing before or after . 
no other servos are effected. the throttle servo does flutter slightly. but not like ailerions. 
1. checked all wires . 
2.unplugged each alieron one at a time and it still happens 
3.these servos are new hitec hs645mg only had them a month. 
4.both Life packs were fully charged

now. this may have happened before I set up this curve . but skipped past it so fast I never noticed ..
now the throttle feels spread and really like the way it feels. (besides this sketchy glitch)
my 1st take off was tense. 4ft off the ground hit 20% ..full deflection hard left bank ..almost caught the wing. the rest of flight was good. even with the crazy 25km winds today at high speed .head /cross wind didn't cause any surface issues. 
I feel like it's the throttle servo . 
was told I shoudnt have and noise effecting things 
but could it be that particular rpm range creates a vibration or frequency that might do this ? 
I'm going to buy 3 new servos tomorrow and swap out both wings and throttle. unless someone can give me an alternative culprit.
Sign up now
to remove ads between posts
Aug 03, 2019, 05:03 PM
Registered User
doug14's Avatar
Thread OP
quick vid
My escapade glitching (1 min 6 sec)
Aug 03, 2019, 05:39 PM
Registered User
Try using a different receiver or even different transmitter. I lost a couple of really nice planes due to a bad receiver. I fought twitchy ailerons thinking the entire time it had to be the servo but found out the hard way it was really the stupid receiver.

carl
Aug 03, 2019, 06:25 PM
Registered User
koppterX's Avatar
Doug I suggest you restrict your questions to a single forum. FG guys have far more experience Than most of the rcg folks. First thing is Replace the extensions. I’ve seen and experienced this a few there times.
Aug 03, 2019, 08:05 PM
Registered User
doug14's Avatar
Thread OP
thanks i will buy some new extensions tomorrow also.
next time out I'm going to have a different rx .
then bind my spare radio.
have new extensions .
confirm my plug cap tight.
Aug 03, 2019, 08:22 PM
Registered User
doug14's Avatar
Thread OP
plus I found some specs on the Jr 537 throttle servo. it's pretty cheap. 49oz plastic gear.
yanking that now.
Aug 03, 2019, 11:26 PM
Registered User
koppterX's Avatar
The idea is to isolate the problem. You’re not able to do that if you are changing more than one variable at a time. Change the extensions first. If you are getting into gs you want a healthy collection of various extensions. There is always a throttle position that shakes like hell. Any problem should be independent of throttle position. Good luck.
Aug 04, 2019, 08:11 AM
Registered User
doug14's Avatar
Thread OP
I already swapped out the throttle servo. today I'm buying extensions . will test it tomorrow.
it it still occurs I will try the rx radio swap.
believed to be a bad plug cap connection . but what stumps me is why it only effects ailerion servos and not the 2 elevator and rudder servos. you'd think it would cause all of them to jump.
Aug 04, 2019, 08:58 AM
Registered User
koppterX's Avatar
I agree. I don’t think it is random which would be the case if it was the cap. I also don’t believe it is the rec or transmitter. Plug the old throttle servo into an aileron port and see what happens.
Aug 04, 2019, 02:46 PM
Registered User
Quote:
Originally Posted by doug14
I already swapped out the throttle servo. today I'm buying extensions . will test it tomorrow.
it it still occurs I will try the rx radio swap.
believed to be a bad plug cap connection . but what stumps me is why it only effects ailerion servos and not the 2 elevator and rudder servos. you'd think it would cause all of them to jump.
Mine did the same thing. ailerons twitched. Everything else fine. Makes it look like the servo. It was the receiver. Incidentally, I eliminate using servo extensions by making up a new servo wire at the servo circuit board. Once I cut the wire to length, I crimp new pins on and put the connector together.

carl
Aug 04, 2019, 11:29 PM
Registered User
doug14's Avatar
Thread OP
all fixed and good to go.
it could have been extensions .bought and installed new heavy duty wires .
I guess I won't know but happy it's better now.
the throttle servo helped too.
thanks for all the suggestions
.it all helps
Aug 24, 2019, 10:42 PM
Registered User
doug14's Avatar
Thread OP
got a little taste of my glitch back today.
and it's confirmed it was sparkplug cap.
haven't flown this plane in 20days.. pulled it out today.
fired up. pretty easy too..was bench testing and this time I have mega glitches
ailerion . rudder and elevator jumped and locked . worst still my throttle stuck wide open. I was pretty shocked ...but greatful it happened on the bench not mid flight .
I hit the kill switch. then ignighted before it completely stalled ..3 or 4 times . then shut it off ..pressed on cap really hard and rotated slightly. fired it back up and poof. problem solved.
tested on bench a few times then took it for a very tense test flight.
so glad posted here and learned what I have from the responses. could have lost and or destroyed the plane.
I do plan on selling it and getting something bigger ..60-100cc but I still really enjoy this plane.
Great Planes Escapade (2 min 43 sec)
Aug 31, 2019, 08:30 PM
Go fly a jet today
CARS II's Avatar
Late to the party but here it goes, I've experienced the same problem before, during my researches I found a thread that talked about the spark plug cup and how he tested it, I did the same and confirmed that it was the cup, I end up using a 1/4" worm clamp, it fits over the cup and it doesn't touch the engine, the tension C clamp that the cup comes with is soft and it doesn't compress the cup as it should, I got my clamps from Kragen auto parts, they have them by the counters.
Sep 01, 2019, 07:40 AM
Registered User
The tension on most of those c clamps at the base of the plug cap are what gives a lot of users fits. They're SO stiff the cap is difficult to get onto the plug completely. Once on, the caps have to be pried off using a screw driver. That's the way they're supposed to be, as that is your assurance of a good electrical connection between the plug and the cap. Without that solid connection, well, that's the cause of 99.9% of the glitches you hear about on 2.4 radios.....

That said, nothing wrong with using a hose clamp. Does the same thing (provides a solid electrical connection), only differently.
Sep 02, 2019, 01:06 AM
Go fly a jet today
CARS II's Avatar
Funny thing is that the spark plug cup on my DLE 35 never gave me that kind of trouble to remove or to snap back on.


Quick Reply
Message:

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Motors twitch quarter turns at 0 throttle Kingkong 20 amp casey62 Multirotor Drone Power Systems 4 Apr 17, 2017 10:20 AM
Help! 1 motor sticking/glitching at low throttle, ZMR250 scottishslayer Multirotor Drone Electronics 4 Sep 08, 2015 03:50 AM
Discussion glitching at 3/4 throttle rcalldaylong Electric Plane Talk 13 Jan 05, 2011 03:08 AM
Help! Help Solve glitch at just over 1/2 throttle. Dan_eflyer Mini Helis 31 Apr 02, 2007 12:05 PM
B/L sometimes glitches at part-throttle Ginger Adam Power Systems 0 Apr 24, 2003 05:09 AM