Glitching = crash, any reccomendations?
 

My trex has been glitching a lot recently. I was stupid enough to keep flying it. That mistake ended up costing about $80 in new parts. I was told by somebody at a local meet to use silicon base lubricant on all of the heads bearings to reduce radio interference, he said that's a common problem for glitching. I'm still using FM. Please don't recommend spektrum, just ignore it in this thread, I've decided to wait because of $$$.

I have heard that triflow, sewing machine or air tool oil work well as oils but do any of them contain silicon? If not, what should I use?

I'm also open to any suggestions as to what the main problem (creating glitches) could be. My helicopter had very stable flight until it would randomly spaz (very jittery, quick back and forth movements, even the throttle would go up and down on its own) for a second or two. Right now the rex is sitting on my desk, repaired, waiting for something that will attempt to get rid of this glitch. Also I have checked the tail belt and everything seems fine there. Any suggestions? And what's a good silicon oil that's worth a shot as I mentioned so I could knock that suggestion out of the way?

Thanks!

RE: Glitching = crash, any reccomendations?
 

My two cents tells me that the cause of the twitch might be the chicken pot pie in the microwave. If you are still on FM you are at the mercy of so many things like microwaves, anything electrical. I used to have an axe cpv3 than when in the house or in my neighborhood would just twitch like it was having a seizure, took it out to the park or out in the open and solid as a rock. You don't have to get Spektrum or Futaba or anything highend just any radio that is 2.4 ghz will do the trick. Do I suggest you get a good radio... yes! They aren't that expensive. I bought my spektrum dx6i of ebay for $108 and love it. You might have other issues going on that is causing the fits of excitment in your bird, but I would bet it stops if you take it out to the field.

Also check all your connections see if they are loose. Good luck!!

RE: Glitching = crash, any reccomendations?
 

Not to get in an arguement but there are many great 72mHz radios that work perfectly well.

So lets figure out what could cause interference and then tell your self how you'll fix it.

You have two basic causes of interference using a good radio system, one that has a good transmitter and a good receiver doing their job.

First interference caused by the helo itself;
Bearing noise is usually caused by the high speed bearings that are dry as you are thinking. Main shaft bearings, tail shaft bearings, and motor bearings in electric helos. Add clutch bell bearings in a glow helo.
Lubing may help but often the bad bearing will need to be replaced. Often re routing the antennae may cure it.
ESC and electrical noise from the ESC, motor or gyro is also a possibility. Static generation could also be the cause.

Second are outside RF noises, water meter transmitters have been a problem for me but you can have hundreds of different causes for this.

RE: Glitching = crash, any reccomendations?
 

Thanks for helping me. I'll check as much of that as possible.

I won't rule anything out but the things in this paragraph will be the last things I will check.
The antenna is roughed properly, away from any of the electronics. I don't think motor or ESC noise is the problem since I have the ESC in the front and the receiver as far as possible from the motor in the back, and I haven't heard of gyro noise. The Tx is high quality Futaba. I also sort of doubt that the problem is outside RF noises because it's occurred at my house, the neighborhoods clubhouse where there is sort of a field, and it glitched into the crash at a local park. Not to be ruled out, but not likely.

I have actually read some bad things about the receiver (Align, good brand but their older receivers and servos aren't that great from what I've heard) so that's a possibility. Although for a while it acted just fine.

I will try oiling the bearings first. I'm thinking I'll run to the hobby shop tomorrow and maybe use some 100% silicone shock oil (lowest weight [how thick] they have, probably 10).

How can you tell when you have a bad bearing that needs to be replaced? It will barely spin or something? Also, what do you mean by static generation?

Thanks!

Some pics. Flybar isn't together because I haven't reassembled it yet and the head is lifted so I can lube the shafts bearings quickly, when I figure out what to use.
http://img15.imageshack.us/img15/450/dsc02201y.jpghttp://img30.imageshack.us/img30/8138/dsc02202vt.jpg

http://img29.imageshack.us/img29/6014/dsc02203y.jpghttp://img11.imageshack.us/img11/2065/dsc02205t.jpg

http://img196.imageshack.us/img196/1382/dsc02207g.jpg


P.S. Evan-RCU that avatar is out of this world. I looked at the pic in your gallery. Wow.

RE: Glitching = crash, any reccomendations?
 

The lubrication idea is a bt of a red herring IMO - or more like an urban legend.

BTW, you didn't mention glow or electric. EDIT - We posted around the same time, I now see it is electric.

My money would be on vibration, antenna routing or (if its electric) some problem with the motor / ESC. Could even be a binding servo causing excessive current drain.

There is nothing wrong with 72MHz FM - I've been flying it for over 5 years on the same Tx and RX combinations and never once had a glitch.

Personally, I think most of the people that gripe about FM glitches and run it down are simply trying to lie to themselves and soothe their egos. As soon as they crash, "Wow did you see that glitch??!!"

All my crashes have been down to dumb thumbs and a couple of flame-outs at inopportune moments, no-one else's fault, and certainly not the radio.

Don't forget, if it is genuine interference and you are struggling to get it down safely, then try moving your Tx antenna so it is sideways on to the model. Gives the strongest signal. Don't point it at the model which is normally the first reaction most people have. It'll only make matters worse.

RE: Glitching = crash, any reccomendations?
 

Looking at your piccies I have a couple of questions.

1 - Is that a carbon tube your antenna is running through? Even if it is only black plastic, did you know that carbon is the main constituent in coloring plastics black? You might be shielding your antenna.

2 - Your antenna seems to come from the Rx, forwards along the antenna tube, then back again inside the tube. This is not a good idea. Having the antenna folded up on itself will certainly weaken the radio signal at the Rx. You need to open out that loop. I know the 1 meter antenna is a hassle so I bought myself a base loaded antenna from Quick UK a couple of years back. I was leery at first but it has performed excellently. You can reduce the antenna length by about two thirds and it looks sexy.

http://www.quickuk.eu/cat/radio___el...ies.html?nav=2

RE: Glitching = crash, any reccomendations?
 

I have seen static discharge cause some really crazy things on rc helis. It would cause the servos to all just start dancing around with no stick inputs, although I am not sure exactly why. I had that happen on one of my cf framed helis once and it drove me nuts trying to figure out what was wrong.
I sprayed a little bit of static-guard on the main gear and a little shot up in the tail boom and it solved the problem, at least for a few flights, then it would start again. I used a very tiny piece of wire to ground one of the tail shaft bearings to the boom, then from the boom to the frame and motor mount. Never had another problem after that.
That was however, when I was using a cheap, generic, stock radio from an rtf kit.
I removed all the ground wires after setting it up with my DX7 and never had any problems with it after that.

RE: Glitching = crash, any reccomendations?
 

Sorry I didn't mention nitro or electric in my first post, the thought never crossed my mind.

archiebald, I can agree with you that the silicon base lubricant reducing RF might be a wise tale. Probably any proper oil / lubricant will reduce radio interference just as well by simply reducing metal-to-metal contact. I have a bottle of "Parma TQ Bushing Oil" that would likely work fine. Maybe I should just use that.

I don't think any of the servos are binding but I'll double check. Same with general vibrations, I'll check what I can.

The antenna is running through a plastic antenna tube. With rc cars and trucks, these same antenna tubes sometimes cover the entire antenna, so I don't think that is causing any problems. And about the antenna crossing its own path - Aside from the fact that there is a small gap, I have been told online and in person that this is fine. Also, blade cp's come with the antenna wrapped in a coil around a skid (and the manufacturer recommends that you keep it this way), and I have actually not had any problems keeping it like that on my blade CP. I could just change it though on my rex since I am having glitches, couldn't hurt anything.

Thanks for your advice.

RE: Glitching = crash, any reccomendations?
 

Did you take note of my point about it being a BLACK plastic tube. I don't know if this will be enough to cause a problem, but I only use clear tubes and fuel hose for my antenna.

I would have thought that the people that build the radio are the ones to listen to....

Here's an extract from the Futaba 9C Tx manual - I am sure yours will have the same text in it.

It is normal for the receiver antenna to be longer than the fuselage. (for planks)
DO NOT cut or fold it back on itself — cutting or folding changes the electrical length of the antenna and may
reduce range. Secure the antenna to the top of the vertical fin, and let the excess wire length trail behind. You may run the
antenna inside of a non-metallic housing within the fuselage, but range may suffer if the antenna is located near metal or
carbon fiber pushrods or cables. Be sure to perform a range check before flying.

RE: Glitching = crash, any reccomendations?
 

What I see from the pictures'

Do not run your antennae wire or servo wires anywhere near RF generators (ESC and motor), it looks like a servo or ESC wire is up against the motor. Do you have a ferrous ring on your ESC lead?

The antennae routing you have is fairly normal but I would stretch it to the verticle fin with a rubber band. I would not route it to the horizontal fin like you have it.


Have you done a range check with the TX antennae down? Do you get 30 or more paces away before ANY servos start to act up?

RE: Glitching = crash, any reccomendations?
 

Using FM in a 450 class heli is just a pain. So many RFI inducing devices in a small area. ESC, Motor, tailbelt, Battery and power wires.

Oil all bearings with a teflon oil. (Triflow, Remoil etc)
Retighten all screws and bolts.
Move the antenna to 1/2 way down the skit and move the end away from the static generating tail belt. Tie it to the middle of the vert fin.
Spray antistatic stuff on the tailbelt.
Run a grounding wire from the tailboom to the frame.
Reorient the battery to ESC wires.
Reroute the servo and gyro wires.
Ferrite choke on the ESC to Rx wire.
Buy a PCM receiver. Should be fairly cheap since everyone is going 2.4

Fritz

RE: Glitching = crash, any reccomendations?
 

Yesterday I put the flybar back together and I also bought some tri-flow (teflon oil) for the bearings and main shaft. I'm out of town now but I'm going to try that first (hopefully Sunday), and if that doesn't fix it, I'll work on all the recommendations here starting with re routing the antenna and moving all wires further from electronics. THANKS everyone for all of the suggestions[sm=thumbup.gif] I'll post how it goes and I also have a few tests to try.

EDIT: Just re-read some posts... I do have a ferrous ring on the ESC lead. I have not done a range test in a while, that's something I plan to do. Thanks.

RE: Glitching = crash, any reccomendations?
 

you need to install a ferrous ring on the esc lead like what evan-rcu said, it's a magnet ring. if you do you might have a bad servo that causing the glitch, it happen to me before. test each servo.

RE: Glitching = crash, any reccomendations?
 

what about the belt, ? don't miss it,

RE: Glitching = crash, any reccomendations?
 

Ybenjulkay2x, I have that in the post above yours. I'm not trying to be rude when I say this but I put that edit in (stating that I have a ferrous ring on the esc lead) the day before you posted. Thanks for the suggestion anyways.

Bikemad, that's another thing I need to closely inspect. Although I know there are no problems like the belt having a twist, it could be causing static electricity.

Here's currently what's up... I put tri-flow on the main shaft, main shafts bearings, and on the tail slider, and I reattached the head to the heli. As I mentioned, no test flights since the crash. Test flight today wasn't good - now the tail is giving me crap. Wagging all over the place and I tried adjusting the gyro gain, that doesn't seem to be it.

Thanks again everyone for all the suggestions. I'll work on it more probably this weekend and I'll post any results. The tail shouldn't be too hard to figure out then I'll be back to working on the glitching.

RE: Glitching = crash, any reccomendations?
 

Two great (glitch free) flights yesterday and two today:D

Thanks again everyone for all the suggestions[sm=thumbup.gif]

RE: Glitching = crash, any reccomendations?
 

So what did you found about the glitch.

RE: Glitching = crash, any reccomendations?
 

Oiling the bearings must have done it[:o]

The thing is, I was trying to save time by trying to figure it out before I finished the repair. I had 4 or 5 bad flights before it finally crashed (talking about before I started this thread), and that's all that's different after reassembling it, so that must have been the problem, dry bearings causing interference issues.

RE: Glitching = crash, any reccomendations?
 

have you try with a PCM Recevier?

RE: Glitching = crash, any reccomendations?
 

I just did a search to confirm that my receiver is PPM[:o] and I discovered that the difference is that PCM converts the analog to digital. A futaba 6ch PCM receiver is $80 so I'm going to hold off for now. My receiver seems 100% fine. I will be upgrading to spektrum eventually though.

RE: Glitching = crash, any reccomendations?
 

I have had the same problems with 3 of those align receivers in 3 different models, the problem was never solved until the receiver was replaced[:o]

RE: Glitching = crash, any reccomendations?
 

Maybe that's why they're $20 receivers[:o] I've heard that aligns older receivers and servos are bad. Everything else they make is great.

Something crazy happened at the park today. I was flying in maybe 10 mph winds, and all of a sudden I watched a wasp fly quickly right at me, it landed half on my sunglasses and half on my eyebrow[X(] The wasp then tried to get under my sunglasses and onto my eye. I didn't flinch and somehow managed to bring my heli down for a safe hard landing, then when I took my sunglasses off it flew away. I thought, what are the chances. There's always gotta be something to worry about while flying[:-]

RE: Glitching = crash, any reccomendations?
 

yes don,t muck around with cheap receivers in models like this as there to costly to repair. i must say i ,ve bought some great receivers at around the $20 mark [ corona dual conversion fm ] but only for my 3D foamies. with Helis , especially electric helis you really should use good brand pcm receivers not single conversion either as they hate electrics.

RE: Glitching = crash, any reccomendations?
 

I agree, Align offers good quality mechanics at an affordable price, however I would go for PCM at least if you can afford, but definatly 2.4 is the way to go. It could just save you money in the end;)