2.4 Spektrum shutdown / lockout / reboot

[rkeith2]

Anyone else running 2.4 spektrum and suffered a reboot or failsafe?

Running a Wren mw54 on 7.4 lipos thru fadec and 2.4 7000 RX on Duralite with switched regulator at 5.2. All 9252's and 611 gyro.

I fear this has caused the last two crashes and after repairs today in a hover it went into failsafe and shutdown.

I can monitor and load all servos with rapid stick movement and the gyro screen always stays at 5.2volts.

I think I am ready to go back to channel 19

[lperagallo]

Ron,

See my reply in Bergen section.

Lou

[rkeith2]

I was getting the brownout and reboot while using my Duralite 4000 flat pack with the associated 7.5 Amp switched regulator at 5.2 volts. The Duralites are from 2005 but were up to par and holding a good charge even when loaded to 3 amps.

Here is what I changed to:

4000 MAH LiPo 2s1P into a 10 amp adjustable regulator that I set for 6 volts. I also place the 4700uf 10v capacitor in an open receiver slot and put the 5.1 volt regulator between the 611 amp and tail servo.

No problems today and I will be flying some 3D tomorrow and will then check over the flight logger for errors.

[bcook01]

Ron

Maybe I can make a few suggestions or comments. Will try and keep it short.

The 2.4 ghz radio receivers are only as good as the power supplying them. This pretty well stands for any current electronics. The 6+volts for the receiver is a good idea. I believe one of the major causes of lockout is due to the common power supply leads between battery /receiver / servos. Any fluctuation on load is going to change the voltage at the receiver, especially with current use of digital high output servos! This is based on the resistance of the wire between the battery and the receiver.

1)I am suggesting using a device such as the glitch buster (http://www.emsjomar.com/) which allows isolation of the servos with the receiver.

2) Switches can be a real problem. There I am recommending using double pole switches or TWO in parrellel. It is cheap insurance.

3) Use low impedance batteries such as nicad or lipo for receiver. If you go with full isolation then just a standard receive pack is sufficient as the receiver load is only milliamps.

4) make sure the grounds are seperate if you are using only one battery.All grounds should terminate at the battery connector.

5) keep power leads short between battery and receiver.

6) use a cheap small AM radio and "snoop" for noise. reduce where possible and use shielded braid on long servo leads to reduce RF emission.

7) isolate receiver from the fadecs. they produce a lot of harmonics and noise. keep any power leads SEPERATE! I am sure this receiver can is susceptible to noise on the batt lead (as is most cmos logic).

8) Use minimal connectors and make sure they are good ones such as deans.

If you isolate the receiver then the capacitor is of no use, however, it won't do any harm either. (as recommended by Spektrum)

9) you can use two four cell packs (with a two diodes in series with ONE pack) going to the receiver. In this case you have full isolation and dual pack redundancy. The diodes gives you a 1 volt drop which is nothing but provides backup when the primary pack drops by 1 volt. This can be a four cell "AA" battery pack as backup. Switching regulators can fail and are not really needed for such low power requirements when driving receiver only.

Last but not least I would use a glitch monitor tied to one of the servo outputs. Jomar makes one. (I use the voltage and glitch monitor on an ap2000i). It is good insurance in the event the receiver goes south for some reason. It also provides good isolation between receiver and servos. Also use it to do the 4/90 mixing.

If you monitor the voltage fluctuations at the receiver with a "scope" using a regular installation while wiggling the sticks you would be surprised. The wire size between the battery and the receiver is just too light for peak currents of 15 amps or more.

Also do the "walk test" with the glitch monitor as part of the preflight using the low power switch (as in the dx7). It is a good way to monitor any deterioration of the receiver.

I consider this cheap insurance. Some form of glitch monitor is imperative.

hope this might help.

Bob

[lperagallo]

Gee and to think all I use is the duralite pack suggested for the Bergen and a DX7. Now the power to the Fadec and the RX are separate, but I mount the RX on top of the Fadec with a small piece of foam between them.

Never had a glitch, lockout or reboot. I will admit that power can be a problem, but I doubt we are drawing more then 7.5 amps and while redundant power is a safety feature, I have yet to see a complete loss of power in flight. I always do a load test before each flight to make sure I've got enough juice so I feel safe.

Bob, your suggestions will certainly help eliminate a catastrophe, but at what price. I would think the added dollars are weight might not be worth it. If I had $10,000 in AP equipment up there I'd agree with you 100%, but for 3D flying our dumb thumbs will get the machine faster then any complete power failure.

Lou

[bcook01]

Lou

These were only suggestions depending on the existing setup. If the servos are already isolated from receiver then there is no issue.

It is easy for higher power digital servos to hit 3-4 amps on stall. Also a shorted servo can create problems.

An isolated power supply of four AA batteries is not much weight for a 90 series helicopter. I certainly would not bother using this on a trex 450, however, if I want to protect a turbine or the intreped then going the extra mile would safeguard a power supply problem. You are talking less than 8 dollars including a radio shack battery holder. The diodes are 50 cents each. Mind you it is rather redundant if you have a generator on board. Maybe I wasn't clear. ......... By adding four AA cells and two diodes you can protect the receiver from a reboot or power loss due to low voltage. .

I have had no problems with the the 7000 receivers and a dx7. I was able to improve the sensitivity or range by optimizing the position of the receiver.

I have witness a few random glitches but no brownouts. Depends on your overall investment I guess. I try and keep ahead of Muirphy. ;)

happy new year to all.

Bob

[rkeith2]

Thanks for the input and I agree with the current drops over the small gauge wires for sure.

[Dilbeck]

Sorry to chime in here but I dont get it, Why in the world other than rf interferance would you have a problem, whats this about voltage, Ive got a dx7 and have never ever had these problems, ive ran my batt down below the caution point so many times it would have seen something of the same your talking about. One persons reception is another persons noise! Their is something else in the 2.4 ghz range causing these problems i am shure of or i think im sure of, Everything now runs on the 2.4 ghz band because the 60 to 900mhz was full, cell phones, internet, home phones, wireless everything is 2.4 ghz, no matter how spred spectrem or whatever there will be some sort of override when serching through the many channels. Check this out , if i boot up my dx7 in the house next to my cable modem all hell breaks loose and then it gets a grip, then it will loose it all of a sudden, But if i get in the back yard no problems intell i hover over the roof of the house not all the time but some of the time i will get a glitch ever how small it may be you will notice it strait away. Not sure where your flying but it would seem to be a RF problem, If you take 2 transmiters on the same freq at the same voltage in the same space the one with the most voltage will override the other. Ive seen this in freq from 5 to 2000mhz. Check the area your in, May be wrong but would like to here something to dispute this.

[lperagallo]

Bob,

I do not have my RX and servo power separate, just power separation between the Fadec and RX/servo. I am curious about the website you have posted and the product. Is it the Glitch Buster 8 that isolates the power from the RX and servos so you plug a battery into the Glitch buster and another battery to the RX? Then the Glitch buster supplies all the power to the servos from the power attached to it? If so do you know if there is any latency in the signal going thru the glitch buster or does it pass the signal from the RX straight thru to the servo and feed the power from the glitch buster.

If that's how it works I agree that's a better set up them I am using. I would need to add a battery for the RX, although that would need to be very big. Also since I have switchless power to the Fadec and need to plug it in at the beginning of the day, I guess I could go switchless to teh glitch buster.

Thanks for the info,
lou

[rkeith2]

Okay -

No errors at all again today on the flight logger so i am pretty happy that the brownout - reboot issue is solved.

Punched out straight up with the new pump and its getting "fuzzied in" and all seems good with the turbine and electronics and I am okay to keep an eye on the curves as it settles in.

No vibrations at all and solid however I noticed a weirdness on tracking which I will be investigating this afternoon. Takeoff and flew around and tracking was spot on and coming in it was off as much as a turn and then as fas as it occurred I lifted off again and tracking was good "weird"

[rkeith2]

Found it -

Loose mixer arm bearing.

[lperagallo]

Ron,

Have you tried the new dampeners from Bergen. They are easy to install, seem to last a lot longer then the o-rings and so far the only weird thing is that they need to 'warm up' on the first flight. My tracking is always a tad off on first flight and 5 minutes later everything is fine for the rest of the day. It drove me crazy the first couple of times it occurred because I started it up saw the tracking was off, adjusted it back in, then as I landed I saw the tracking was off again. I ended up going back to the original setting and it was fine the rest of the day. I think I went through that drill three times before I said let's try to fly gently the first couple of minutes and see what happens. It's not off enough to cause any vibes, so I just fly away.

Lou

[davidbklein]

One time I experienced a strange tracking/out of track thing also. I found it to be a bent feathering shaft-as the shaft would turn in the head, the tracking would come and go.

Dave

[lperagallo]

Dave,

My tracking doesn't go in and out. First couple of minutes of flight on cold day it's out. Then for the rest of the it's spot on. I noticed it when I was flying under 38 degrees on a couple of days.

Lou

[bcook01]

Lou

This also occurs on full scale. Always had a rough ride in a 47 or 206 until the moisture was dissipated. Could be coefficient of expansion on the blades or rotor system.... temp equalization etc. Doesn't take much.

what kind of blades?

Bob

[lperagallo]

Bob,

I run 810 Vblades.

Lou

[jgunpilot]

Ron

Maybe I can make a few suggestions or comments. Will try and keep it short.

The 2.4 ghz radio receivers are only as good as the power supplying them. This pretty well stands for any current electronics. The 6+volts for the receiver is a good idea. I believe one of the major causes of lockout is due to the common power supply leads between battery /receiver / servos. Any fluctuation on load is going to change the voltage at the receiver, especially with current use of digital high output servos! This is based on the resistance of the wire between the battery and the receiver.

1)I am suggesting using a device such as the glitch buster (http://www.emsjomar.com/) which allows isolation of the servos with the receiver.

2) Switches can be a real problem. There I am recommending using double pole switches or TWO in parrellel. It is cheap insurance.

3) Use low impedance batteries such as nicad or lipo for receiver. If you go with full isolation then just a standard receive pack is sufficient as the receiver load is only milliamps.

4) make sure the grounds are seperate if you are using only one battery.All grounds should terminate at the battery connector.

5) keep power leads short between battery and receiver.

6) use a cheap small AM radio and "snoop" for noise. reduce where possible and use shielded braid on long servo leads to reduce RF emission.

7) isolate receiver from the fadecs. they produce a lot of harmonics and noise. keep any power leads SEPERATE! I am sure this receiver can is susceptible to noise on the batt lead (as is most cmos logic).

8) Use minimal connectors and make sure they are good ones such as deans.

If you isolate the receiver then the capacitor is of no use, however, it won't do any harm either. (as recommended by Spektrum)

9) you can use two four cell packs (with a two diodes in series with ONE pack) going to the receiver. In this case you have full isolation and dual pack redundancy. The diodes gives you a 1 volt drop which is nothing but provides backup when the primary pack drops by 1 volt. This can be a four cell "AA" battery pack as backup. Switching regulators can fail and are not really needed for such low power requirements when driving receiver only.

Last but not least I would use a glitch monitor tied to one of the servo outputs. Jomar makes one. (I use the voltage and glitch monitor on an ap2000i). It is good insurance in the event the receiver goes south for some reason. It also provides good isolation between receiver and servos. Also use it to do the 4/90 mixing.

If you monitor the voltage fluctuations at the receiver with a "scope" using a regular installation while wiggling the sticks you would be surprised. The wire size between the battery and the receiver is just too light for peak currents of 15 amps or more.

Also do the "walk test" with the glitch monitor as part of the preflight using the low power switch (as in the dx7). It is a good way to monitor any deterioration of the receiver.

I consider this cheap insurance. Some form of glitch monitor is imperative.

hope this might help.

Bob

Or you could buy an XPS module and receiver and enjoy flying.

[wirlybird]

Rkeith 2 , don't have a clue what your problem was , but I have a rule off thumb , all my batteries go into the bin when they reach 3years no matter what their condition , so far so good!!
Dave.