servos chattering
 

guys, is it normal for these spectrum DS-821 servos to chatter ? i have these connected to a JR [ R-700 ] receiver with a 4.8 volt battery pack.

RE: servos chattering
 

Is it cold where you are? if you put little coats on them they won`t chatter:D

RE: servos chattering
 

They must be female servos. Replace them with male servos and youll be alright.

Opps did I say that out loud.

Sorry dont have those servos, but as they are digital its generally normal for digitals to chatter.

Cheers

RE: servos chattering
 

I use JR821 servos. I do not notice them chattering. I have forgotten which airplane I have them in. You have got me searching.
I have been building and flying R/C planes since 1978 and control line planes since 1956. My first radio was a 1978 Futaba 6ch. Over the years, we have had to deal with chattering due to dirty pots, overloaded servos, poor range, RF interference.

I currently have a JR XP9303 with a Spektrum module and one with a 72Mhx Synthesizer module. I also have a Futaba 9CAP with a Synthesizer module. The non 2.4 receivers are all PCM.

Except for Digital servos that Whine, I do not remember having servos Chatter any more. The PCM receivers go into FailSafe, if the signal is lost, so the servos go to Preset positions or just Hold. With non PCM receivers, the servos would chatter if there was Interference or if I was past the limit of a Range Check.

I use mostly Hitec analog and digital servos. I have Futaba 3114 serovs in my Electrifly Seawind. I have Eflight servos in my Eflight Extra 260 flat foamie. The Hitec digitals are in the 87" Extreme Flight Yak54, the QQ 72" Yak54 and my Kangaroo jet. I have JR servos in my H9 P47-150 as I bought it with servos installed.

I do not have anything against Futaba or JR servos, I just have had good luck with the Hitecs and saved some money.

RE: servos chattering
 

The DS821s should not chatter with your config. If it does, it should go away with the tx switched on.
The servos could also chatter if the voltage is too low.Check the battery voltage under load.

RE: servos chattering
 

Are you inside and do you have any Fluoro lights switched on in the room?

I bet that sounds like a weird question to some but let me explain

The OP is in australia - 36 MHz radios.
The power there is 50 Hz this seems to bring the frequency from the fluoro lights (maybe the ballasts or the starters - I don't know much about it) close enough to cause servos to chatter.
I have quite a few planes that chatter inside when the lights are on - especially Fluoro lights. - turn off the lights, or take them outside and the problem goes away.


Otherwise - tell them to behave themselves and be quiet or you won't buy them an ice cream when Mr Whippy comes down the street next.:D

RE: servos chattering
 

steve, this chattering also happens at the flying field when doing the normal range check, when the tx antenna is down i get about 10 foot away and they start chatting but the range is good and all controls work fine. there are no problems flying the model but i really dont feel safe with this problem as anything could happen sometime, if these ds-821 servos would shut up i would feel relaxed. the way these start chatting seems like a range problem but as mentioned i have good range.

RE: servos chattering
 

any of you guys use these DS821 servos with either a JR - R600 or R700 receivers ? if so any chattering of these servos ?

RE: servos chattering
 

Digitals are known for chattering, particularly the zero dead band .
If you really are concerned, then disconnect all linkages and see if they stop chattering. They should either stop or decrease markedly.

I do not use either Rx you mention but the DSM2 Tx/Rxs chatter the least.
The others chatter more, and that is normal.
The chattering is the servo searching for neutral____a tight neutral____.

RE: servos chattering
 

I had this happen once because of a aileron linkage not having enough play....it was too tight. If you take the pushrod off one side (either servo side or surface side) and it stays there....not dropping on it's own, this can cause chatter as well. Just a thought,
Kevin

RE: servos chattering
 

what i really can,t figure out is, i have another model with the same receiver and same servos fitted and have never noticed any chattering but with this other model in question the chattering is a pain or a worry to me as it doesnt seem right. why do all servos chatter ? is it because one could be abit off and setting off the others ? as mentioned i have tried a different receiver / battery pack / switch. the only difference in servos between the two models is the chattering model does have extended servo leads for the rudder and elevator servos as there mounted in the very rear of the fuselage [ Katana 3D Model ]

RE: servos chattering
 

I had this same scenario. Make sure your linkages are not stressed.

Have you swapped the two Rxs in the models.

Also take the Rx & servos out of the model an try it on the bench.

This may be able to isolate whether its the installation, Rx or servos.

RE: servos chattering
 

two things you could do.Try using a 5 cell pack.There could be a voltage drop to cause the servos chattering as you have servo extensions ,especially so if you use nimh batteries.Have this happened to me before. Conversely, the extensions could be causing rf interference and may need ferrite rings.

RE: servos chattering
 

i,ve done some more tests on the model with these sus DS-821 servos, re- positioned the aeriel wire which sort of made some very slight difference to the better, re charged and tested the rx battery pack under load all good . now another question; when i am close to the model there is no chattering of servos but as soon as i walk away with the transmitter antenna colapsed i get to about 15 feet away and they start the chatters but if i raise the antenna abit all is fine again. when doing a range check with antenna down i get a good 100 feet and with the antenna right up i get more than enough range, what i feel is the radio could have some sort of close range problem when the antenna is down but when its up all does seen OK i did also plug in 2 non digital serovs to the aileron plug and they didn,t chatter only a slight hum which did sound normal. any ideas guys ?

RE: servos chattering
 

I have not owned a DX6, 6i, or 7, although I have helped others with their DX7. I just know that with my JR8103, JR9303, and Futaba 9CAP, I do not get servo chattering, at close range, unless something is blocking the signal or the signal is weak.

With a non 2.4 system, I would route the Rx antenna outside the plane and perhaps even the Rx itself. In your case, with a 2.4 Rx, why don't you set the receiver on a table outside with a battery connected as well as an 821 servo and an analog servo. Make sure it is out in the open with no metal buildings or structures or chain link fences and do a range check with the button depressed. This takes the plane out of the equasion. If you can borrow another Rx of the same type, repeat the test with that. If someone has a Tx like yours, repeat the test with that Tx. This will give you an idea if your equipment is behaving properly in your enviornment.