sudden shudder in flight why???

[4503D]

The last couple of flights ive made I have for no reason a sudden shudder on the helicopter. It only lasts a second or maybe two at max. Im not doing any 3d but just seems to happen randomly. Does anyone know what could be causing this?

[jcmo]

Originally Posted by 4503D

The last couple of flights ive made I have for no reason a sudden shudder on the helicopter. It only lasts a second or maybe two at max. Im not doing any 3d but just seems to happen randomly. Does anyone know what could be causing this?

Sounds like you may have acquired some carbon/gunk in a servo. It makes them twitch when passing over a specific range of motion where the dirty contact area is. Symptom in flight might look like a brief "wet dog" shake that comes and goes. According to others' reports, some Deoxit contact cleaner (or other contact cleaner that leaves no residue) sprayed into the servo and worked around for a minute or so can fix it without disassembling. You use the heli's controls at all extremes with a battery plugged in and TH on to accomplish the cleaning. It's also advisable that if you attempt to do this on the frame you should definitely shield the rest of the heli from unwanted overspray from the contact cleaner using tissues or cotton balls or something.

I personally have removed mine, taken them apart, and cleaned the insides with a cotton swab soaked in alcohol. At first I wasn't sure what part to clean, so I just wiped over everything carefully, and got a bunch of black stuff off the little aluminum fingers on the servo slider and the contact area where they touch. If you use this method, be careful not to snag any cotton fibers on anything, leaving them behind after you are done cleaning.

Either way, it should work like new afterwards, just don't lose or strip any of those TINY screws

EDIT: This post was edited several times over the course of 15 minutes to make sure I didn't leave any details out. I felt like my initial response sort of glossed the topic without enough specifics.

[4503D]

Thanks for the advice. I know what I will be doing this. Do you have a cleaning productbname you could rrecommend?

[Guapo131]

I recommend Deoxit brand spray (basically this stuff).

Here is a thread from the mCPX forum that explains how to clean the servos (the thread suggests isoprop alcohol, but again, i recommend the deoxit).

Also, i agree that dirty servos are the most likely cause of your shakes.

[GoatRider]

+1 for Deoxit, and also +1 for that thread on the mCPX forum. I used Isopropyl and then Deoxit on the same servo, and the Deoxit got some smut off that the Isopropyl didn't.

[Wildcat1214]

I have the exact same issue. Push the main gear up the shaft. When the gear slides down it loses a connection with the motor causing a CRAZY vibration. When the regains a connection and the vibration goes away.

[TracesOfNut]

Hi,

Previously I had seen the random shudder with the stock components on my nano. Sometimes it occurred when descending but more strangely when just hovering 5' up.

I just installed the MicroHeli power package for my nano. The instructions didn't seem to show installing the o-rings on the swashplate server ball joints, so I didn't put them in. When I was hovering, the nano did the shudder every 10 seconds or so. I put on the o-rings after reading comments in a youtube video and it fixed the problem straight away. Now it is so stable, I can go hands free and it just sits there. It is amazing to fly. I don't do any 3D, just flying around in the lounge room and landing in small areas. I have just setup my TX with lots of exponential which makes it easy to add little corrections. A big change over when I first flew it,

Since getting the Nano, I have found a lot of things that needed to be adjusted 'out of the box', each improving things a bit i.e. Blades were too loose, Main gear wasn't glued on and was slipping, feathering shaft needed adjustment. None of these were obvious to me at the time.

btw, the stock swashplate had a bit of slop, but once I had rebuilt the head and re-glued the main gear, if flew nicely. The MH power pack makes things tighter but it also looks sweeet.


Justin.

[vtown nick]

Originally Posted by 4503D

The last couple of flights ive made I have for no reason a sudden shudder on the helicopter. It only lasts a second or maybe two at max. Im not doing any 3d but just seems to happen randomly. Does anyone know what could be causing this?

Are you running bullet blades or the 3d blades?

The stock main shafts have a good deal of run out and you can cure it with the bullet blades or buy a decent aftermarket solid cf main shaft. After a few crashes your back in the same boat. It flys great with the bullets and they do mask some of the small problems this little guy can develop.