Strange lockout/glitch...

[the collective]

My Fury Extreme is doing something odd. The radio is a Futaba 9C with the 149DP PCM RX on channel 35. No one at the field besides me is on 35.

Last time out, I waqs flying and went to do an auto. As I hit hold and the engine slowed down, I lost all control for approximately two seconds. During that time the heli was slowly yawing to the left, and pitching forward . THere was absolutely no control on any channel. When I did get control back I was able to land safely and immediately shut it down.

Range testing with the engine on or off showed well over 100 feet with the antenna collapsed.

I ran it up without the blades and found that I could repeat the lockout almost at will. It only seems to happen as the engine is slowing down to idle.

Has anyone seen this sort of thing? I'm suspecting it might be my voltage regulator, because a few of the times I made it happen on the ground it seemed the servos moved to the sides rather than just lock in like they would on an RF glitch... I've got the regulator mounted to the frames right next to the engine on a thin layer of servo tape... probably not the best place for it.

[ErichF]

Check the RX very closely, Twice I've had the servo pinout board come loose from the motherboard. The pinout board doesn't have much of a stress relief built in.

I've also just gotten over a long, drawn out RFI issue with my Fury, and found a couple items. PM me for details....


Erich

[Joel Mann]

The clutch bell assembly may either have a bad or loose bearing as mine did..Its very easy to fix..When you take it apart if the bearing slides off, red locktite it back on..some use green,just whatever..

As Erich stated, closely check your buss bar on the receiver...Turn trans and rec on and move the servo leads around.I have had a time with bad receivers to..I hope this helps..

[Russ McC]

I've also just gotten over a long, drawn out RFI issue with my Fury, and found a couple items. PM me for details....

Hay Erich,

Don’t leave us all out of the loop post your findings hear so we can all learn something form your experiences. Thanks :wink:

[ErichF]

Sorry, didn't mean to shut everyone out, I was at work and couldn't provide all the details at the time...here's a copy of what I wrote back to The Collective:

"OK, where to start

I had to isolate each and every electrical component, starting with the switch and moving through the GV1 and Gyro. After doing all that, I found no issues.

I did replace the 5253 on rudder and went to test fly. I had a good 8 minute flight with no problems, until suddenly the thing went into lockout half way through a split S and nosed straight into the dirt.

It involved a major rebuild as both frames were broken. During the rebuild I found the fan shroud screw tips were contacting the engine cylinder head. I also found a couple questionable bearings and replaced them. I even replaced the engine because I was suspicious of it's bearings.

Took her out and flew a couple tanks off no problems. After the third refueling, spooled up and at a certain rpm, the CCPM servos would lock up in a slight negative pitch, and the throttle and tail still responded to inputs. This is strange because it violated my PCM failsafe settings (idle and neutral everything).

Go back to the drawing board and re-arranged some wiring and replaced the switch. Flew it again, and was ok for about 8 minutes. Then in a 5 ft hover encountered lockout and she went down on her tail. Surprising little damage occured, only the vertical fin broke on the tail.

The lower horizontal frame plate was cracked in the crash, so required replacement. During that replacement, I noticed two missing bolts that go up into the forward vertical channel from the bottom. This allowed that plate to rub through the anodizing on the channel and generate RFI.

Replaced the plate and installed all the required bolts, and she's been flying fine since. I have about three trouble free gallons through her now.

I was told during the process that the boom struts can come loose inside the ball end, and create RF, so check that also.

This is a very frustrating process, not to mention potentially costly as it can be mostly trial n error, with failures usually resulting in a crash.

I'm glad I got through with it with only two crashes. "

One thing I also failed to mention was the R149DP Servo Pinout Board was found loose during the first rebuild...could have be a contributor to the crash, or occurred in the crash itself.

In the end, she's flying like new. One thing that's true about this hobby, you have to love working on these machines as much as flying them.


Erich

[Russ McC]

The lower horizontal frame plate was cracked in the crash, so required replacement. During that replacement, I noticed two missing bolts that go up into the forward vertical channel from the bottom. This allowed that plate to rub through the anodizing on the channel and generate RFI.

That's a new one to me :!:

I was told during the process that the boom struts can come loose inside the ball end, and create RF, so check that also.

This one is also new to me. Thanks for sharing :glasses2:

[ErichF]

I think the boom struts would have to be incorrectly assembled in order for them to come loose...I'm assuming it was meant that the carbon tube can vibrate on the steel rod that's supposed to be glued into it and the ball joint end. For that to happen I think you'd have to omit glueing the rod into the carbon tube, or use very little glue.

The horizontal plate rubbing the vertical channel end was something I would have had a hard time finding if the plate wasn't busted. I have no idea how long those two bolts were missing. Serves as a reminder to often check the bottom of these machines just as well as the sides of the frames for loose/missing hardware.

There was a pretty good abrasion in the plate from the channel, and the channel end was like polished aluminum. The tell-tale goo of oil/carbon/aluminum wasn't apparent as usual in that area as I always wiped it down last (when the rag was quite dirty already.)


Erich

[the collective]

I finally managed to find some time to look things over. Turns out my problem WAS the voltage regulator. I took the heat shrink off and found one of the FETs (the one with the heatsink) had two broken legs. The only thing keeping them in contact was the heatshrink squeezing it together. Under the right vibration, the legs would go in and out of contact intermittently.

Now for the bad news...

I've been down for several weeks, no flying at all since it first started glitching. Yesterday was very windy, gusts to 35MPH+ and my rusty hands and you can guess what happened... I blotched an auto and SLAMMED him into the ground...

I guess the up side to it is I've now got the perfect excuse to upgrade to the Stratus...

[the collective]

As Erich stated, closely check your buss bar on the receiver...Turn trans and rec on and move the servo leads around.I have had a time with bad receivers to..I hope this helps..

Speaking of this issue... I just recently smacked a Rap50 and now the receiver is acting dead... it's a Futaba 149DP receiver, and it acts pretty much stone dead until I wiggle the battery/servo wires at which point it'll come alive for a fraction of a second then go back into hold...

Is there a way to fix the pinout board myself or does it have to go back to Futaba? I'm not afraid of soldering in small spaces. I had a look inside the receiver, and even separated the two boards, but I don't see any obvious breaks between the servo pinout board and its motherboard...

Thanks in advance...

[WillJames]

Send it back to Futaba, but once you get it back be VERY careful. With a few people I fly with all the time as witnesses, I have had 3 149's that I sent back to Futaba with Buss Bar troubles that were repaired by Futaba and TWO of them failed with more buss bar problem again! One of them made it 3 flights on my electric Raptor 50, and the other I sold to Hammer and it did not make it through ONE single flight at the B-Ham Event this year in his R90. (Great Event by the way David. :glasses2: ). The 3rd RX that was repaired stopped working during a flight at Clints a few months ago and my 9CHP could not make it work at all, but his 9Z could.

I will no longer be using repaired by Futaba RX's under any circumstance. 150 or so for a new 149 or 319 is good insurance ona 3+K Heli. I am running 2 new 319's right now and they work great. I vibration isolate all my RX's with foam and never directly stick them to anything with double sided tape.

All in all, I have sent back one 601 and 4 RX's to Futaba for repair. The 601 is still bad and was not fixed, and 3 of the 4 RX's has failed again. I am running the remaining "Tuned" and filters replaed 148 in my TREX. Anyone looking for a great deal on the remaining 149? From now on, I just trash the stuff, replace it and avoid the unneeded aggravation and frustration.

[ErichF]

Will,

I sent my 149 in for the same repair, and when I got it back, I found the SAME issue upon re-installation!!!

I normally get great service and repairs from Hobby Services/Futaba. However, I don't think there is a reliable fix to this. The RX is made by machine in a factory on a jig. No human can effectively repair it, apparently.

So, I now have 1 148DP and 1 149DP sitting in a drawer waiting to go into something expendable :twisted:

Erich

[tnreefguy]

This makes me feel bad since I run two 149dp's one in my extreme and one in my airwolf.

[WillJames]

I normally get great service and repairs from Hobby Services/Futaba. However, I don't think there is a reliable fix to this. The RX is made by machine in a factory on a jig. No human can effectively repair it, apparently.


I think you are right Erich. I wish I had known/realized earlier. I know a few other people who have had the same kind of issues.

[the collective]

I had a similar experience with a repaired Futaba receiver back in 1991 or so. I had intermittent lockouts and sent the receiver to Futaba with a not explaining the symptoms. It came back to me "fixed" in a week or two, then failed on the morning of the F3C team trials during a practice flight. Utterly destroyed my TSK Black Star.

I don't think I'll be sending my 149 in for repair, better to replace with new.

On that subject, does anyone know which of Futaba's PCM receivers is the most solid and reliable? My buddy flies a 148DP and hasn't had any issues so far. I know there is a 138DP, a 148DP and the 149DP.

[ErichF]

I have been flying 148DPs now for quite awhile without issue. Both in helis and 35% Planks. Seems pretty much bullet-proof.

Erich

[the collective]

I heard the same about the 148Dp from a friend... I went to the LHS where I work part time and grabbed a 319DPS today. At my cost it was only $12 more than another 149DP.

If it gives me any issues at all I'll drop a 148DP in there.

[WillJames]

I've been flying the 319's since July 4th weekend and so far nothing but self induced problems. ;)

[the collective]

I've had a few of those myself... :wink: