Newbie needs help with Glitching

[daniel reese]

Well, at least that's what I think the problem is....
NEVER FLOWN RC ANYTHING... I am THAT new to this stuff!

Two weeks ago I picked up a new trex combo from HongKong and got set up pretty quick. All went well, had managed to spend 5 battery packs in a fairly steady hover (3' sphere).
Anyway, I had been training myself in a gym and had noticed only about 4 or 5 instances where it seemed the model "twitched". It would jerk right or left rudder for a fraction of a second and then nothing for a long time. Sometimes it would seem as if the motor shut off for just a fraction of a second and come right back..then nothing for a long time.
Anyway, i just figured it was RF interference from something and since it really was manageable, paid it no mind.

Sunday night I was in the parking lot in front of my appartment in a very slow and steady and smooth forward flight about 3' off the ground and it "glitched" again, but this time it was severe!

The motor seemed to shut off, the cyclic jerked hard left, rudder went right and it dropped pitch to 0 and hit hard at a right-roll angle.

The main blades disintegrated, the boom looks like something hit it- its bend about 5 degrees left at the root then about 20 degrees right at midboom. The tail flat cracked, the main shaft bent, the main gear is out of true, the skids broke and the front of the bottom plate broke off.
All in all, not a catastrophic crash- about $80 in parts so it doesnt hurt too bad but I dont understand what caused the problem.

Im using a Futaba 6EXHP radio at 72.950 MHz with some Other-Than-Futaba-Rx (PPM) with an installed crystal labeled "-RX58-". The Rx is mounted just under the battery tray about 1/2" from the Algn 430L motor with a ferrite ring on the throttle connection. The Align 35 ESC is mounted on the outside right side of the frame. the long antenna was routed under the body, up one of the carbon tail boom supports, over the aluminum boom, down the other support into the plastic tube on the skids.
This is one of the SEs with carbon frame, anodized aluminum rotor head and tail using stock plastic tail blades and 325 PRO wood main blades.

Ive read through about a thousand posts on glitching and such and there seems no single answer but a collection of issues...here's my questions:

Is the carbon frame to blame for RF noise/interference?
Does routing the antenna along the carbon frame and boom supports introduce problems?
Does having the antenna near the ESC cause problems?
Does having the Rx so close to the motor cause problems?
Is there any credibility to the theory that the aluminum head creats RF noise?
Is there any credibility to the theory that the tail drive belt generates RF noise?
Will a "Glitch Reducer" help?
Can I switch to a Futaba R138DP rx on the same band reusing the same crystal without sending it off to Futaba for matching? Would that help?
Can I switch to a Futaba R146iP and reuse the old crystal without sending it off to Futaba for matching? Will it help?
Would just switching channels (crystals) help?

Wow, thats alot of questions.

I would really appreciate ANY help.

Dan The Newbie

[swatson144]

Not really a lot of questions just one Why don't I maintain contact with my heli? :D

I'm gonna start by saying I have my own opinions and they are opinions just like all the conflicting opinions you have read, and of course to say I'm sorry to hear about the damages/crash the 1st one sucks pretty bad, but that's about the average for a mini. Around 75$ and 4 hrs.

You weren't very specific on the RX and most likely it was the most of the cause, not all but it didn't seem to reject noise well. I am a firm believer in the Berg or other DSP/TSR RXs. I'm also a firm believer in using the manufacturers crystal. I don't have glitches they aren't allowed. 1st sign I start moving stuff. On the maiden hovers I use an elcheapo single conversion GWS RX for testing. If it glitches I move stuff, if not it gets a good rx and I don't have to worry about it hiding a glitch. The 2.4G is well worth a look but I'm ignoring it as you are invested in 72Mz.

On the CF frames. They are conductive and sharp! That's a dangerous combination that isn't warned about often enough. Check all your wires for nicks. If you find one it could be the problem. short the red and the black and you'll have no control I guarantee! Ground the antenna same.

Wire routing.. get a base loaded 10$ antenna. some people say they affect the range and they are probably right. How far away can you see a mini? running antennas down CF or any conductor is not a good idea, I think the compact antennas are the best compromise, and use them. Mostly the ugly old deans but a few micro lite on my micros.

On the Fut RX...You can buy a High band RX for your chan 48 tx and a crystal no need to send it off for matching. Don't use anything other than a Futaba crystal. They work for some but when they don't work it compares poorly with the 10$ value wise. Even if it doesn't cost a cent but you still have glitching you just can't rule out that a 3rd party crystal isn't the cause and you wind up with one any way.

On switching channels... 2 different locations and repeatable glitching. Not likely a frequency problem. I'd rule that out. Most likely all the out of time signal reflections just exasperated the problem in the parking lot.

Just some mention of how I set mine up (mini and larger). Gyro as far away from everything as I can get it. Same with the RX. gather the power stuff in a knot. My venerable x400 is setup (very sim to Trex 450) with ESC up forward, GY401 between the frames in back and berg 6 rx on left side of the rear frame http://www.jacobwatson.com/x400.htm should give you an idea. http://www.jacobwatson.com/heli is my heli page.

Hope some of that helped, I'd really suspect the CF frames sawed/shorted a servo wire. CF frames aren't evil and I own a couple you have to protect the wires well and really secure them.

Steve

[daniel reese]

Ive seen those Deans base loaded ant. How do you attach / connect them? Is the existing ant wire just shortened, spliced & soldiered in? What other options are there for shorter antennas? Where do I find them?

None of the wires are cut or nicked but I will wrap them all securely just to better protect them.

Balance has been an issue. With the aluminum tail hub, the tail is heavier than the earlier versions and I have to push my battery WAY out front to counter that weight. That was why I had my rx up there too. The gyro is in its factory location - over the tail boom and seems to perform VERY well there. Ive read of cases where they get knocked off or damaged in a crash but Im a bit reluctant to move it since it works so well where it is....

Could you explain "Berg DSP/TSR"?

If I move the ESC forward, it will be under the canopy, will that affect its heat dissipation?

Thanks so very much for all the help!!

[swatson144]

Deans.. They come with a small plug and socket. I use the connectors when it is needed for ease of maintenance, else I just solder. Yes the Ant needs to be cut and I put the wire back in the RX box for later if needed. They are every where along with the micro lite and Azur, all work well IMO. The deans are rugged and I just mount them with hot melt and a nylock for security. (for a mini you'd want the deans 1 pc).

I still don't know what brand RX you are running some of them like the Blue arrow 5ch need to be in the spares box to avoid glitching. :shock:

Bergs... http://www.castlecreations.com/products/berg_7-channel.html why reinvent the wheel CC explains it well. I've been happy with Peter Bergs receivers since before CC bought them, improved them and lowered the price. Even my beloved moth has a berg 4L 8) They are small light and work well.

ESC ... I don't have an align on any of my helis. Nothing bad to say about them but I'm ignorant on the subject. It should do fine under the canopy. As always stop and check often until you are sure there isn't a problem.

Gyro... position of the gyro don't matter. It's better near the main shaft as the amplitude of vibrations will be less there but other than that just having it properly mounted and access to the controls is all that's important. IMO gyros tend to cause glitching when wires are bundled with other wires. Not in the form of glitch you had though. It's more of a nuance, than a calamity.

I'd say we are back on the RX?

Steve

[Sleepstalker]

Any discoloration heat marks ect on your ESC? Did you buy a brand name Ferrite choke such as JR and loop it at least 4 preferably 5 times around the choke and as close to the RX as possible ? When running your antennae wire allow no contact with sharp carbon frame or sharp aluminum frame components , using short pieces of fuel tubing and wire ties in the areas you want to tie down to . will provide good insulation and dampning . Make sure that you are using a good Futaba RX and Futaba RX crystal . Did You buy the TX new ? If so the question of the TX crystal is solved . I would concentrate on buying a Futaba RX crystal and borrowing a buddy's RX to use it on if not . Crystals are 7-8 bucks a pop and a good 6 channel RX about $60.00... 8) ...Sleepster

[daniel reese]

This whole thing came as a mostly preassembled kit that was supposedly "tuned" although I found that not to be the case. All parts "appear" to be new, many were still in their wrappings.

There is no evidence on the ESC or the motor of heat damage and Ive never felt substantial heat from them (checked often, always only just warm)

The rx (and everything else) is at home, im at work, cant check the brand name from here. Its black with gold label and black writing...., and the servo ports are in the end, not on top like a Futaba. The crystal is in the other end..maybe that helps. I remember its NOT a BERG and its not any name that Ive seen anywhere.

I dont know how new the tx/rx is but it appears to be brand new. I dont know why the kit didnt come with a Futaba rx....

The ferrite collar was already on the wire and it IS wrapped 4 or 5 times and its as close to the RX as I can get it (moved it intuitively I guess).

Dont have any buddies to test equipment with....if you could see where I live, you would understand- this is so far out in the woods we have to truck in the sunlight!

Looks like Im shopping for an RX...
Just to be certain, My TX is Futaba 6EXHP using 72.950 MHz crystal; the current rx uses a "-RX58-" crystal. Can I fly the R138DP high band with a Futaba "CH58" (72.950MHz) crystal or Futaba R146iP (says high AND low band) with a "CH58" (72.950MHz) crystal without the need for any retuning or factory service?

I just plug the servos into the proper ports and off I go? Is it really that simple?

[swatson144]

Not quite that simple. Any time you make changes to the radio gear (good idea before any outing) do an antenna down range check. Naturaly it's a good idea to test and make sure the swash moves as expected before you consider the job done.

About 15yrs ago I flew PCM it was the best option. now I think DSP is the best option (outside of 2.4g). That is just my opinion.

Steve

[daniel reese]

I understand the importance of testing before one would attempt to actually fly the thing, it just seems too easy...
Its my own brand of psychosis that I tend to expect EVERYTHING to be more difficult than anyone claims....anyway...

Been reading on the CC website...this Berg Rx...like a Futaba, essentially plug - n - play? If the crystals (freq) match, it should do what my inputs to the Tx say to?

If I use a Berg Rx, do I need to put a Berg crystal in my Tx or will the Futaba crystal in my Tx work fine?

So...to sum up:
Move the ESC to the front, and the Rx to the back.
Wrap & protect all wires and dont wrap any wires around metal or fiber parts.
Replace long wire ant. with Deans base loaded one.
Get new Rx / crystal(s)

[swatson144]

With the berg (or any other RX) you just get the crystal to match your TX freq. That simple.

Check to make sure that the servos are indeed plugged in correctly before powering up and moving the right way afterwards.

Sorry I don't mean to talk to you like you ain't so bright but others behind you might have a tendency to think that their situation is identical and if it worked for you just dive naked into the deep end screaming I'm invicible and not check to see if there is any water :oops: A heli is a terrible thing to waste. You have a healthy amount of caution, Good on ya!

Steve

[daniel reese]

Youz Guyz have been a great help!

Im all excited to get back in the air but I know Im gonna be pretty shaky. That was my first crash and it was pretty scary, Im gonna be cautious to the point of absurdity when I get this thing back together.

Had all the mechanical parts inbound already, should be here in a day or two; still need to decide on which of the Rx & antenna recommended...leaning towards Berg (cheaper too)

How about LiPo alarms? I dont want to overdrain my pack. The Align ESC has a battery protection function that can be set to reduce power at X volts and cut power to the motor at X volts. There are two settings and I picked the more conservative of the two during setup but as I understand it, the ESC is not necessarily an accurate measure of battery voltage and could trigger prematurely or post-maturely (is that a word?).

Anyway, there are a few LiPo battery alarms out there- are people using them to good effect? Is this a worthwhile investment? I saw the DIY alarm post- thats quite a bit out of my skill range at the moment but not beyond what I might attempt; if its appropriate for a 11.1v 16-22c batterypack on a T-Rex 450SE...

What say ye?

[swatson144]

I run the Berg7 on my freestyle and that's ~2 trexs worth in the air.

The HR-PolyX is a hard to beat alarm. I run them or the DIY, to protect me from doing something stupid. I don't want to let them tell me to land but the TX timer instead, so I land with 70-80% of the pack used. I usually set the LVC on the ESC as low as it will go so it's disabled. I don't want reduced power if it gets to that point I'd rather damage a pack than crash a heli. Just hovering around soft cutout LVC should be OK set conservatively. Again you want it as a last resort and to set your timer. If you can hover 10mins with a fresh pack before LVC set your timer to 8mins etc. the last 20-30% is the hardest on the pack and the most sluggish.

Steve