When engine runs servos begin to glitch
 

Hi Guys,
I picked up my 1st giant scale airplane from a estate sale. The plane is a Byron Husky with ST 2500 engine. The plane was not flown in many years, still had a AM receiver and old style connectors on the servos. The servos are for giant scale, and I had to re-solder new connectors on them . The battery that I am using is a 4.8 volt 1500 mah . Do I need a 6 volt perhaps? When I do a range check without the motor running, all is fine. As soon as I start the engine, the control sufaces go crazy. The attena goes straight down and is outside the fuse, so what can my problem be? I never had this problems with any of the plane sI have owned?
Kind Regards,
Frank

RE: When engine runs servos begin to glitch
 

Did you switch over to a dual-conversion FM receiver? Also, check for any metal to metal contact in the aircraft. Just a couple of ideas.

BB

RE: When engine runs servos begin to glitch
 

Hi,
Yes ,I put a new dual conversion recever in. I have been thru the entire airplane and can`t find any metal to metal contact.
Frank

RE: When engine runs servos begin to glitch
 

Bypass the on/off switch and see if the problem persists. If the glitching stops, install a new heavy duty switch.

RE: When engine runs servos begin to glitch
 

Okay I`ll try heavy duty switch. Do you think I`m still okay with the 4.8 volt battery or is it nessasary to go with 6.0 volts? I`m only using two gaint scale servos , rud. and elev. the rest are standard servos.
Frank

RE: When engine runs servos begin to glitch
 

skrez , If the glitch only happens when the engine is running I dont believe changing from 4.8 to 6.0v is going to improve the situation.
I would check the throttle linkage to be sure that there are no metal to metal contact points ( clevis to throttle arm especially ) .
If there are no metal to metal contact points start isolating servos by disconnecting them one at a time and rechecking for the concern with the
engine running , this will isolate the cause to specific chanel where the interference is being induced . Possible causes could be a bad servo
pot effected only when the vibration from the engine is present or possibly a bad servo wire extension and the pin contacts are being etched by the
engine vibration .
Good Luck ,

RE: When engine runs servos begin to glitch
 

I've seen the exact scenaio you are describing. A guy brought in an old trainer that the servos went nuts with the engine running. Was a bad switch.
Edwin

RE: When engine runs servos begin to glitch
 

Yep, I missed a major fly-in several years ago, because I could not find a glitch with the engine running. Finally bypassed the switch and all was good. I guess the contacts in the switch were corroded, and lost contact due to vibration.

RE: When engine runs servos begin to glitch
 

Hi Guys,
Thank you for all your input, I found the problem last night. I had an bad extension wire on the charge jack end of the swich harness that had exposed wire touching metal inside the fuse. I changed it and all the glithing went away. Thanks to all again.
Regards,
Frank