Electric retracts with glow engine problems
 

Hello all,
I'm experiencing some electric retract issues that are blowing my mind and was wondering if anyone else has seen this and possibly have any ideas.
I recently finished a new GP Patriot and decided to go with electric gear after 25 yrs of not a single failure with the mechanical gear in my old Patriot. The maiden flight was good with no issues. Starting on the second flight one or more of the gear would be extended or half extended randomly in flight. It has progressed to the point that the second I advance the throttle, the nose gear with retract and extend constantly. Further throttling up, one or both mains will retract, half retract or cycle. Obviously at this point, it is unflyable. All 3 gear are plugged into the gear channel of the 7 channel Orange RX. Transmitter is a JR 9303, and if it matters, the eng is a YS 45 with a tuned pipe. If anyone has any ideas, it will be appreciated.

Cody

I forgot one thing, when the engine is not running, they work perfectly.

It's possible the battery pack isn't big enough to handle the current for the servos and the retracts under load. That is where I'd start

I had the same problem as you with a 6V 1600ma. battery. I went to a 2200ma. 6V battery and all cleared up. I fly classic pattern birds, It pulls a smaller battery down when all three gear start at the same time.

I may not have been clear about what's going on. The gear are coming up, going down, cycling uncommanded, I'm not moving the gear switch at all. Gear switch is in the down position. They only start to malfunction once the engine is running and just above idle. I have stirred the sticks on the transmitter and operated the gear to maximize the batt load and they work, go up and down responding to the gear switch normally ( without the engine running ) . With the engine running, they go up and down, independently, and I am not moving the gear switch.

I'm using a 2000mah LiFe

Sounds like you have a cracked PC board on one of the gear or a loose wire, usually the nose gear. The vibration is sending a false signal.
I used to find the same problem on wire harnesses in the Navy. So many cycles and traps would tear up the avionics and wire/pin connections.
http://www.rcuniverse.com/forum/atta...mentid=2207755

Well I will start looking at that, sounds like a very good possibility. I guess I could unplugged the nose gear and see if the problem in in that retract. Thank you.

We used to call them "Phantom Gripes". Worked great on the deck but computer dumps in the air or system off line. Also check the Y-harness. Do you have a engraver or something that vibrates so you can touch the gear/harness/receiver with?
Many years ago in high school, I used to work at a Kraft Radio repair depot and that is how we would find many receiver problems. They would work OK on the bench but fail w/ just a touch of vibration.

Not to change the subject but that pictured Prowler is newer than any I ever worked on. We had a couple that were just trashed electrically. I know 158030 was almost beyond hope when we got it from 136( attached to the USS Midway in 1985) and 160609 was only marginally better even though it was always in my squadron, based at Whidbey.

That's a great idea, thank you. I don't have one but I can get one

Ok we have progress. I put battery power to the rx and without the engine running the gear would not respond to the gear switch. The gear were down and would not retract. That's a new one. I unplugged only the nose gear and the mains worked perfectly. While leavin the rx powered up, the gear are down, gear switch is down, I plugged the nose unit in again and the mains retracted, uncommanded and the nose stay down. So mains up, nose down and none of the 3 will respond to the gear switch. I unplugged the nose again and the mains extended and matched the position of the gear switch. So thanks to the responses here, I think We have isolated the problem to the nose unit or the Y. I'm glad I asked, thanks again.

Cody

Cool, glad we could help.

I just experienced a bad new "Y" cable. Intermittent! Found it purely by accident - fortunately just before maiden of a new model.