Bill,
I just opened the boxes containing a new W.H. 28% Edge. This will be my first gasser, so I have been following this thread with interest and a little trepidation ( I am a relatively new re-enty RC guy). The level of trepidation was raised a little by the fact that I am planning to use 5645s on the ailerons and elevators.
I have experienced a similar situation (Hitec HB475s..although I don't think the servo manufacturer is pertinent) in an airplane that I had been flying, without problems, for several flights. This airplane has an FMA FS8 receiver..no copilot..with the annunciator panel attached. Among other things, the annunciator panel will indicate the number of times during a flight that the receiver reverts to Fail-Safe mode. This is a PPM receiver but it has progamable fail-safe settings. I had not programmed the fail-safe in this particular plane (BTE Flyin' King).
On three consecutive flights the throttle, and only the throttle, would glitch to wide-open. The glitches lasted a few tenths of a second. At first I was not sure that I had not inadvertently opened the throttle myself (I have not been flying RC for fifteen years!!!). No other channel was affected at any time..just channel three. By the way, the transmitter is a one-year old Futaba T6XAs. All the batteries were charged and good, switches were all fine, no apparent source of on-board RF noise, just no indication of airborne anomalies.
After the third time this happened I finally thought to look at the annunciator. This set-up had been flawless in all (12 to 15) previous flights and I had grown lax about checking the annunciator after each flight. Anyway, the annunciator was indicating that the receiver had, in fact, reverted to the Fail-Safe mode. As the children say, "DUH!!".
I checked all of the airborne components and found nothing malfunctioning. I sent the transmitter and receiver to FMA for a check-out. The receiver was fine. The TRANSMITTER had drifted off frequency. According to the technician at FMA it is not uncommon to find TXs off frequency and not too uncommon to find them off-frequency right out of the box.
I am not an engineer or electronics technician so I can not verify what he told me. I do know that retuning the transmitter has apparently solved the problem. No more fail-safes, no more glitches, and the receiver is giving me much "cleaner" (fewer bad frames) range checks than ever before.
I think I will still use Hitecs in my Edge and an FS8 PPM receiver. However, the entire airborne system is going to be "burned-in" for a few hours prior to the first flight.
Good luck with your plane-wrecking anomalies. And, keep this thread going.

I ordered a Fortress 2000 receiver from FMA last week. I will switch the Futaba out as soon as it arrives. For now at least, I am putting the PCM receiver in a U-Can-Do .46, with a mix of Futaba and Tower Servos. Once I get to test the FMA in the Edge I'll post the results. Seems like a better way to go than replacing the 8611 (more money for less servo) and still worrying about the HiTecs glitching some day with the Futaba receiver. I've never had a problem with a PCM receiver in a glow engine powered plane, but I'm a little snake bit about using one in the Edge right now. The FMA is PPM and still has a Fail-Safe feature (I think). Thanks to rlmcnii, I will look into the annuciator panel. Sounds like a great idea.

Bill Gavin

rlmncii,

I can't find the annuciator panel on FMA's web-site. Is it part of the Co-Pilot package or one of the flight packs?

Thanks,
Bill Gavin

Bill,
http://www.fmadirect.com/Detail.htm?item=1785&section=1
Look at his link. It is the FS8 receiver without the Co-pilot components, but with the annunciator panel. I do not think that either the Fortress or the Quantum receivers will support the annunciator panel. The annunciator is very handy. It will record the history of the signal received during each flight and it is also a handy voltmeter. One can read the on-board voltage while exercising the servos. Perhaps not as good as a loaded meter, but much better than reading the voltage with no load on the batteries.
Read the info with the receiver about determining the quality of the signal your Tx is putting out. May be helpful.

Received this from JR Porduct Support:

Bill,

Thank you for your recent email. Unfortunately we do not do any cross-brand testing of our products with other manufacturers products. So we can not verify whether our servo would operate properly when used in conjunction with another manufacturers receiver. I apologize that I could not be of more assistance.

I hope you find this information useful. If you have any further questions, please reply to this email or give us a call at 877-504-0233.

Thanks,
Tobias
Product Support Team Member
Horizon Hobby Distributors
4105 Fieldstone Rd.
Champaign, IL 61822
877-504-0233
[email protected]

Well, at least they answered. Not sure how to feel about the fact that they don't cross brand check anything. On the one hand, it would be almost impossible to check every combination of different brand receivers and servos. On the other hand this problem has been around for a while and you'd never know it without Forums like this. I guess from now on if I mix any equipment I'll have to search high and low on the RC Forums for issues like this. Clearly it is not as simple as just PCM technology being OEM proprietary.

Bill Gavin

Bill,
MY problem was apparently the TRANSMITTER, not anything airborne. Although, my son-in-law had a problem identical to yours in some kind of a STIK using a Futaba PPM with Hitec servos. Whatever it was got his ailerons, once right bank and once left bank. He has not yet had his transmitter checked for accuracy of frequency.....But, he is going to!

Hi Bill, as my father in law (rlmncii) mentioned in the previous post, I had a problem that sounds strikingly familiar to your problem. The setup I was running was a Hangar 9 Ultra Stik 60 with an OS 60, 6 Hitec 5645MGs (control surfaces), 1 standard servo (throttle), Hydrimax 1650 mah 6 V receiver batt, Futaba R148 PCM receiver (with no fail safe set up). I had many flights on the stik before I first noticed the problem. The first time I was at a farm field in the country with no other flying fields around. We did the typical range check, actually to ~200 ft. I flew 2 flights with no problems what-so-ever. On the third attempt I was on the runway just about to throttle up when the left aileron parked itself at full up deflection and the servo was making a kind of jittery noise. I obviously decided to call it a day and investigate the problem. When I turned the rx and tx off and back on the problem went away. Needless to say I was baffled. I had created some of my own extensions for the servos, so naturally I thought I screwed something up. I checked, and triple checked every solder point and every connection with no problems. I did end up replacing a couple of questionable extensions and thought the problem was fixed. I went to my local flying field some time later and checked out with a range check and everything seemed good, so I flew 2 or 3 times. On my last flight I was just messing around with some aerobatics when the plane went into a violent right roll coming out of a botched loop. I had plenty of altitude to figure out what was wrong, so I recovered to level flight holding full left aileron to keep the airplane flat and level. I immediately brought the plane around for a downwind approach and thankfully was able to recover the plane with no damage. When i got to the airplane this time the right aileron was parked up! I was even more confused. So, I turned off the rx and tx and once again the problem went away. I trouble shot the whole system again and made sure every connection was secure, everything was fine. I didn't fly again for a while, but the next time I flew I did another range check at the local field and everything was fine. I didn't know how to get the problem to surface except to fly and I felt confident that if it happened again I could land safely like I did before. I flew 2 or 3 more times and on my last approach I was flat and level and just bringing back the throttle when, bam, it rolled HARD left about 15~20 ft off the ground. I was right on top of it, but this time I didn't have enough altitude to recover, so I went in nose first, but almost leveled out before impact. The firewall tore loose and the throttle servo jammed, but otherwise i was surprised to see the plane in tact.
I never thought much of the problem because I could never trace out the problem in the electronics on the bench. That is until I read this thread and saw two other cases that sounded very similar. So, after thinking about what happened to the stik and trying to trouble shoot all of the things I could think of, it sounds like it was either two bad hitec 5645s, the rx went bad, or my tx is off frequency like rlmcnii mentioned. I am going to be sending in my tx for a !QUOT!tune up!QUOT! shortly. I will let you know if I have any other problems after I get it back. Although, if it makes any difference, I have never had a single problem when using FMA receivers. I have about 5 or 6 of them and rlmcnii has about 3 or 4. Good luck figuring out what happened, and I am sorry that you had to find out about that by getting your brand new edge banged up.

~Rich

I am 99% certain that I have found the problem - an incompatibility between Futaba receivers and other brands (some?) digital servos. To summarize; with the Futaba R127 reciever and only the JR8611a servo attached to channel 4, the servo will randomly twitch causing the rudder to jerk violently to the right about two inches. When other servos are connected the "noise" gets on other channels and causes them to twitch as well, most noticeably the right airleron which deflects upward. The combination of these two (rudder right, right airleron up) would cause a sudden roll to the right which is what I experienced. The duration is brief - 1/4 second perhaps, and then the servos return to center. All of this is without any transmitter input from me. On my 2nd flight it appeared that the plane just wanted to roll into knife edge right for no reason. To me that sounds exactly like the result of the glitch I am seeing. I should receive a Fortress 2000 receiver from FMA today. We are then going to perform some oscilloscope measurements of the Futaba R127, FutabaR138 and the Fortress. We'll throw a HiTec receiver in the mix if we can find one. I will post results later.

Bill Gavin

This is a good informative thread Bill. It should be troubling to all running different gear though their planes. I'm currently running JR 8611's all the way through my Edge, with a Futaba R149DP Rx. To date, I've had no troubles. My club recently moved to having all Tx and Rx frequencies checked to ensure matching. I'm not sure if that will prevent any problems in this instance, but it eliminates an issue in that regard.
Good luck in finding the issue, please keep us informed.

Regards.

You are experiencing the same condition that I encountered with the 8411's and the Futaba Rx several years ago. Occasional to severe glitching, with a reply to a similar question sent to JR like you received. The same question sent to Futaba received the reply "that sometimes long servo leads cause radio interference" Never could figure out how she equated the servo leads with the problem I had at the time.

The solution was simple, either change out the servos to another brand or change radio systems used.

Pat

Silversurfer,

Beginning to think you are right, except that I have now tried a different brand receiver and still have glitches caused by the JR8611. I did some oscilloscope measurements over the weekend. Not sure what they mean, but maybe someone will recognize something that I am missing.

Voltage measured between ground and signal wires with servo plugged into one side of a "Y" and oscilloscope connected to the other, plugged into channel 4.

Receiver = Futaba R127DF

No Load Signal 6.72 V Ground 0.0 V
HiTec 5645 Signal 6.0 V Ground 80 mV
JR8611a Signal 6.48 V Ground 0.0 V

The HiTec caused no observable gliches. The JR caused sporadic, violent glitches. There was a fairly constant noise ripple running through the pulse at about 5.68 V, with the JR.

Receiver = Futaba R138DP

No Load Signal 3.04 V Ground 0.0 V
HiTec 5645 Signal 3.00 V Ground 480 mV
JR8611a Signal 2.70 V Ground 0.0 V

No glitches were observed with either servo despite the elevated ground voltage with the HiTec and the lowered signal voltage with the JR. This would seem to be the result of the PCM receivers ability to ignore bad data. However, the original, in-flight problem occurred with this receiver.

Receiver = FMA Fortress 2000

No Load Signal 3.12 V Ground 0.0 V
HiTec 5645 Signal 3.12 V Ground 80 mV
JR8611a Signal 3.00 V Ground 0.0 V

No glitches were observed with the HiTec servo connected. Regular, minor glitching occurred when the JR8611a was connected (movement of the rudder back and forth about 1/4 inch).

Although the FMA receiver did not exhibit the violent glitching that was observed with the JR8611a, it still glitched regularly in a minor way. My conclusion at this point is that the 8611a has got to go. A different brand, non PCM receiver did not eliminate the problem. My flying buddy has seen the same type minor glitches with his WH Extra and the JR8611. I think he is using a HiTec receiver, but I'll have to check and make sure. He has not been willing to fly the plane until the problem is resolved. Given that we are both seeing the problem, it does not seem likely that I have a "bad" servo, but the only thing left to do is send it back to JR for them to test. It is useless to me at this point. I hope all this has been useful. I am going to go with the FMA receiver and replace the 8611, probably with a HiTec servo.

Note: Glitches occurred with no transmitter control stick movements. Glitches were observable as physical rudder movement and as changes in the pulse width on the oscilloscope. Normal pulse width (stick centered) was 1.5 ms at a frequency of every 20 ms for all receivers. Engine was not running.

Bill Gavin

Sounds like you may just have a defective servo.

After reading this thread I was beginning to wonder a bit how my set up would react. I've recently begun building a WH 28% Edge540T with the following radio gear.

TX - JR 9303
RX - JR 649S (9 ch PCM)
Servos:
Aileron (1 per wing) - HS-5945MG
Elevator (1 per half) - HS-5945MG
Rudder (1) HS-5955TG
Throttle (1) HS-425BB
Choke (1) HS-425BB
I have not bought batteries yet but I was thinking of going with dual 6.0v 5cell 1950mah NiMh (do you guys think this battery choice is good)?

I have not installed any of the gear in the plane yet but I hooked it all up on the bench tonight with all the extensions. I had to use a single 4.8v 800mah NiCd to power the RX & servos. The only thing I noticed was the two aileron servos were making a very slight ringing sound but there was no noticeable movement. If I just barely moved the aileron stick the ringing goes away but it would start again when I let go of the stick. I forgot to change the fail-safes from the default setting. I was told when doing range checks to have the fail-safes go to full travel on all channels so a fail-safe condition can be easily detected. I will do the test again tomorrow.

Have any of you had any problems with this combination of gear or is the problem Bill is having just with Futaba RX and JR servos?
Is the ringing of my aileron servos anything to worry about? I have herd that digital servos often have a slight jitter when a RX battery is freshly charged. The battery I used tonight was charged about a month ago but has not been used. I would think by now the charge has dropped some. I will also try hooking up two 4.8v batteries tomorrow. Is there any problem with running this set up with 6.0v 5 cell packs? Would regulators be needed to protect the RX?
Thanks WW2 Ace

Overall your selection will be fine. Hitec and JR mix well together. I don't personally care for Hitec, but a good many others do.

I believe that you will have a personal issue with the speed of your throttle servo after you get the plane up and flying. The high peformance servos used on the flight surfaces are faster and much more precise. What will happen is that after you get used to the plane and you start into a bunch of 3D stuff you will have problems with the timing between the throttle responses to the maneuvers. A digital or coreless servo would serve your needs much better. Even a "baby" digital like the standard JR shipped with their radios would be better for the throttle. Ask RTK. He's experiencing the same thing right now.

Most good digitals will make some noise when they are working. Unless you have balanced your control surfaces, and most do not, a digital servo is not truly at idle when at neutral. It's holding up the weight of the flight surface to maintain neutral. It shows up quickly with the better digitals when you turn the radio off. The horizontal flight surfaces all drop if you don't have a lot of bind in the hinging.

If your going to need to purchase batteries, why not spend a few dollars more and get lithions and fly for several days on a charge and come in lighter that with the nimh? No memory, hold a charge for months at a time, lighter weight.

Plugging 2-6v batteries into the Rx won't hurt anything. You should not need a regulator with a 6 volt installation. Don't do that with the ignition unless the manufacturer specifically states that it's ok. In that area stay with 4.8 volts. Some servos will be a bit "jumpy" on a fresh 6 volt charge, others will not. This was originally particular to the JR 8411 servos.

Pat

Pat thanks for the info. I have a JR 811 that came with my radio. The speed is .18sec/60 deg. @ 4.8v (can't find speed for 6.0v), would this be fast enough or would you recommend something faster? The Hitec 425bb is .21sec/60 deg. @4.8v and .16sec/60 deg @6.0v. I thought about lithions but the added cost for the batteries + regulators + new chargers didn't add up well. On top of that I here they are not real user friendly (charging wise) and they can catch fire easily. I have been told the weight you save on the battery you lose when you add the regulators. The ringing I was refering to is with the servo not hooked up to anything. I just have them sitting on the bench (no control surfaces hooked up). Is the ringing in this condition normal?

Thanks again
WW2 Ace

You don't need 2-1950 mAh batteries in this bird. I've got the same plane, same servo's (except 5945 on rudder), and just using one 1950 NiMH with two leads and two switches. I can get 7-15 minute flights with reserve left. In my other 28%, I'm running 2-1100 mAh 5 cells/2 switches. Same flight times.....

This is very true..I went from a standard 3004 futaba to a JR 811 and noticed immediately the difference..the 811 can be had for 45$

I may have to give one a try sometime. I'm still using my ole' 148's. But.................I still have to program in a throttle curve, so does it really make that much difference? I'm just not one to slam the throttle stick around anyways.

YEP! You can really notice when you have to give quick bursts of throttle both up and down..there is no delay like I got with the 3004 and I also have a 5 point curve setup on my throttle..I could even tell just revving the engine on the ground!

I've got an extra 5945 laying around, think I'll put it in and give it a try.....

At the moment I'll just be happy to get my Edge in the air and not see any glitches, but what do you guys think of either the HiTec HS-925MG or the HS-6965HB (digital) for a throttle servo? Both are .08s/60deg @ 6v. Is a digital servo on the throttle desirable?

thanks,
Bill Gavin

If your using digital servos on everything else, you would benefit by using a digital on the throttle. Josey Wales followed up well with what was started about throttle servo speeds and types, and his experience with the differences are the same as I experienced by changing from analog toi digital. To qoute "You can feel the difference!".

A super duty digital with a lot of torque is wasted in the throttle position, but one that is both fast and accurate with relatively low torque ratings would be perfect.

Pat

I had a similar problem with a Harrier90. Could not get the twitching to stop using a Hitec receiver with JR125MG servos. Replaced the JR servos with Hitec and flew the plane. Nothing wrong on the first two flights and then with my brother at the controls the plane violently banked right with no warning. He managed to get it straightened out only to have it bank again and hit the ground. He flys a WH Edge 540T, Obsession 3D and Funtana 90, so he knows how to fly. Firewall torn out but no other meaningful damage. Was discussing the crash with the owner of the hobby store and he asked it I was running a Spectra module in the Optic 6 transmitter. I said yes and he gave me a fixed channel module to use. He said that when they were flying combat and switched to the switchable frequency modules they started loosing planes, quickly. Went back to the fixed modules and everything returned to normal. I sent my Spectra module back to hitec for testing but I don't think I'll fly with it anymore. The plane has numerous flights since the repair with no adverse servo twitching or unexplanable events of any kink. I'll probably put the spectra module on ebay.