Was flying my Kinetic 50 with my DX-6 yesterday and it started to do some really weird stuff like pitching forward from a hover and going into forward flight without me moving the sticks, or suddenly it would start to climb. Not sure if the pitch was changing or if the throttle was blipping. Ended up crashing the damn thing because it started to fly away from me and I was afraid that I might lose control completely. Has anyone else experienced this sort of thing? It was like radio interference, except I'm on 2.4 ghz so that should happen, right? Prior to this, the heli was always rock solid in a hover. I was thinking maybe the receiver is pooched. Ended up destroying the tail boom, blades, torque tube, feathering shaft, and maybe a couple of small parts in the tail rotor assembly.

If you are using the DX6 remember that it is not a full range 2.4 especially using 6100 or 6100E. The other possibility is you suffered a power brown out on receiver. An other possibility is the wind just simply moved it away from you. And last you may have a bad gear in your elevator servo or bad servo or a loose servo in the tray or ball link on control or bell crank came loose.

Jim

Jim

I checked all of the linkages and charged the receiver battery right before the final flight. There's only one thing that I can think of that was different than the first, 60 or so trouble free flights I've had with the heli. When I originally installed the servos, I used the rubber grommets, but not the metal eyelets in the grommets. I read somewhere that you should always use the metal eyelets. So, I loosened off the cyclic and tail servos and put the eyelets in the grommet. I checked for movement in the servos and didn't see any. Could the metal eyelets be transferring vibration to the servos? With the engine not running, I checked to see if the servos were twitching on their own but there was no sign of that. I don't think it's a range issue because the heli was acting weird when it was only 20 feet away from me.

All systems are susceptable to interference, with the 2.4 it's at a different frequency. There is also a fail safe that can mask glitches in the DX's. Could be many things, metal on metal or bearings are usually the source of RF but it might not be interference...

Once I've done the necessary repairs, I'm going to have to go through all of the bearings I guess. BTW, I fly a T-Rex 450 with the same radio and it's not showing signs of glitching or other weird behaviour.

Evan is correct, it could be a ton of things. Evan has only been in RC since it was invented so he has seen it all. I remember when I was first learning to fly heli's that I had a Concept .30 get away from me. I reality it was a gust of wind that balooned it up and away from me. I did not have neg pitch set at that time because I was just learning. It was very hard to get back down so I just let it fly a few circuits around the field trying figure how to get it down. I crashed also and rolled it down the runway. Great crash though!! After my first lesson in forward flight I programed in -3 degrees of pitch in hover mode . I also felt that I had a glitch. I went on to repair the bird and used the same radio for several years with out a problem. Bottom line is to think out of the box and be brave enough to test it.

Jim

Evan is correct, it could be a ton of things. Evan has only been in RC since it was invented so he has seen it all. I remember when I was first learning to fly heli's that I had a Concept .30 get away from me. I reality it was a gust of wind that balooned it up and away from me. I did not have neg pitch set at that time because I was just learning. It was very hard to get back down so I just let it fly a few circuits around the field trying figure how to get it down. I crashed also and rolled it down the runway. Great crash though!! After my first lesson in forward flight I programed in -3 degrees of pitch in hover mode . I also felt that I had a glitch. I went on to repair the bird and used the same radio for several years with out a problem. Bottom line is to think out of the box and be brave enough to test it.

Jim

No wind at all, and like I said, I did 60 or so flights with no weirdness at all before this incident. At first I thought maybe it was dumb thumbs but really, the thing was flying like it had a mind of its own.

Unfortunately you could rebuild and it be fine... You might fix the problem and never realize what it was... The most common bearings to produce RF are the clutch ones as they are spinning at a higher rate and they often dry out due t othe engine heat. BUT that's not saying it is these bearings or that it is even a bearing.

I would rebuild, put in a DX7 full range radio and try it again...

I'm thinking it's the clutch bearings. I'll check those out and I'll likely upgrade the radio.

It may very well not be though, pull them out and spin them, you'll be able to tell if they're shot easily.

On a side note, how do you regrease clutch bearings, or do you just throw them out and replace them if they get notchy?

Once a bearing becomes notchy, it's done. It means it recieved to much of a side load and the balls in the bearing have dented the race. Only fix for that is to replace the bearings. Concerning greasing bearings, the easiest thing to do is purchase a bearning greaser. They work very well, you can use any grease you prefer and is not a very messy process. Check out Heliproz.com or other online retailers.

The Dx6 isn't a full range system and isn't designed to be used on 50 size nitro models.

You don't use brass eyelets with servo plates.

Actually the prefered method is to obtain servo plates and not use the eyelets if the kit doesn't come with them.