).
Bushwacker
3DRCF Moderator
Sorry for your misfortune dude.
Suds
50cc
Man I feel bad for Xpress. I don't think spare parts are currently available for the 88" Yak since EF moved onto a new 91" Yak in 2013.
Bipenut53
150cc
I had a very strange thing happen today with my EF 91 Extra. I'll try to make this brief. Quick background on the plane, as of this morning I have had 5 and a half flights on the airframe. It is set up with 2 two cell lipo 2650mah batteries feeding a Fromeco Wolverine switch feeding dual power into my AR-8000 receiver and I have Savox 1270TG servos on all control surfaces. All new items except the receiver which was a year old and never crashed or abused in any way. This morning when I was flying it I did a couple blenders and a knife edge spin into a flat spin and then I went back up and tried a half cuban 8 and while pulling up I noticed the airplane rolled left enough that it rolled out of the maneuver. So I tried it again, same result. So I did a harrier down and went into a hover at that point I noticed that only the left elevator was working so I immediately landed and shut of the engine but left the power on to the receiver. The right elevator half was locked in about a 20 degree down position. I checked all the connectors at the receiver and all were in and tight. The left elevator half was working just fine. I did fix my problem with the aileron extensions pulling out from the last flight on sunday. I did do a rebind on the receiver and still no right elevator half working. So I emptied the fuel tank, took the wings off and brought the plane home and put it on my stand. I then powered it up, moved the elevator stick on my DX-8 and still no movement on the right half but now all you could hear was the left elevator half servo spinning internally with no movement on the elevator, obviously stripped gears.... BUT HOW??? Since it sits in my truck with a canopy on the 10 mile trip home and no incidents or brake slams, basically an uneventful trip home. So now I'm getting frustrated!! I have never had one problem with Savox servos, ever! Not to say they cant have problems... I can move the right elevator half and you can feel the gears working inside but I cant get it to move with the transmitter no matter what channel I plug it in to, and the left elevator is just plain stripped. Question is...... What would be YOUR next step? I thought about replacing the servos but I have all the SWB arms that fit Futaba spline, I dont want to replace those, I also thought about replacing the two bad servos and buying an AR9110 power safe receiver in case that caused the stripping and the burnt out servo but all power was disconnected on the way home, how did that servo strip? Obviously I got lucky today but now Im a bit apprehensive to trust ANY servos......... Very puzzled......:cursing:
SnowDog
Moderator
This could be a problem with binding of the control surfaces which would burn out any servo.
Check that the physical geometry of the surfaces, linkages, arms, etc are as close as possible, and use an ampmeter to check for binding (one surface at a time) as you deflect each surface through the whole range of motion.
I use Savox servos and I have not had one fail like that...not to say it couldn't happen...perhaps you could talk to Savox about a repair.
Regardless of what servos you put in there as a replacement, very the configuration before flying again.
Check that the physical geometry of the surfaces, linkages, arms, etc are as close as possible, and use an ampmeter to check for binding (one surface at a time) as you deflect each surface through the whole range of motion.
I use Savox servos and I have not had one fail like that...not to say it couldn't happen...perhaps you could talk to Savox about a repair.
Regardless of what servos you put in there as a replacement, very the configuration before flying again.
Bipenut53
150cc
In the original set up of the airframe I did set my end points of all my servos with my Fluke meter in line just because I was concerned about how many amps were going through the receiver and there was no binding at all on any surface, in fact I got to the end of the adjustment travels and backed off by at least two clicks for each servo.
Xpress
GSN Sponsor Tier 1
The Savox 1270TG has a known issue where one of the gear is 2 pieces pressed together.
This may be your issue.
If you don't want to use Savox servos anymore but want to keep your SWB hardware then I suggest checking out the Hitec HSB9380 servo. 25t spline (same as Futaba) but ultra efficient and more powerful than any digital coreless servo.
This may be your issue.
If you don't want to use Savox servos anymore but want to keep your SWB hardware then I suggest checking out the Hitec HSB9380 servo. 25t spline (same as Futaba) but ultra efficient and more powerful than any digital coreless servo.