Gotchykid, he has ruled out the motor (he has a brushless and a brushed motor he has tried), admittedly I had an astro 010 bearing go out in that same way.

It sounds to me like it's actually one of your mainshaft bearings. When bearings go out, they will sometimes look fine but have flat spots on the balls inside, they will turn just fine at low speeds but at higher speeds the balls put force to the outer race and then they jam, making a high pitch squeeling sound.

You can test your bearings out by mounting a 3mm drill in a dremel tool backwards (cutting edges inside the dremel), put the bearings on the end of the shaft, with some electrical tape to keep them from coming off (simply wrapped around the end of the shaft). Simply turn on your dremel, run it up to somewhere around 10,000 to 15,000 RPM, then simply touch each bearing so that the outside stops, they shouldn't resist hardly at all, if one is bad it will squeal.

-Kai

nice trick! thanks

Thanks for the replies both of you,

Yeah, as Kai has said, I have tested out to motors, so I doubt it is thr motors. And when i just turn round the motor shaft in my hand, it seems smooth...

I will test out the bearing soon!

Thanks a lot, Duane

Hi all again,

Firstly, put in BL motor, spun it up, same noise, put in brushed motor, almost identical noise (dont think I noticed any actual difference).

Then put on blades and head assy. with BL motor, and spun it up. Sounds a lot better (that was probably just the noise from baldes drowning it out though), althought it still didnt sound quite right from what I remember it sounded like before (I havent flown it for ages, first time Ive spun it up today in months, so I may of forgotten how it sounds...).

I then tested out the two bearings that the shaft spins on at the bottom of the frame (one from each frame). Spun them, no noticeable resistance when lightly place finger on outside to stop the outside of bearing spinning. Put a drop of oil on them anyways.

Just wondering, is there much difference in sound between a brass pinion and a plastic one (such as the piccolo ones)?

I dont suppose it would be alright to just carry on and fly it like it is? Its just that I really wanna fly!!!

Thanks all, Duane

I would say go ahead and fly it, you probably just aren't used to the noise the metal pinion makes on the plastic gear (plastic on plastic doesn't resonate very much). Just make sure to double check your gear mesh (I use a piece of paper hand run between the gears).

On my PicPro the gears are all I hear when it is more than 10 feet from me, only within 10 feet do the blades make enough noise to be heard over the gear whine. I run Steel Micro RS4 pinions, and a white nylon aftermarket maingear, my Hummingbird was the same way. Brass gears should be quieter but my Axi powered H2 always made way more noise than my Pic (same head, same blades), even with a brass maingear.

-Kai

Thanks Kai,

I will start putting it together!!

Just wondering, do metal pinions kind of 'wear' in? I mean, like with motors, when you run them in, and then when they are run in, they are quiter, more efficient e.t.c., is it like that with metal pinions?

BTW, its more a screeching than a vibrating, but it almost certainly isnt the motor(s)

Thanks, Duane

Your welcome minimole,

Unfortunately metal pinions don't wear in, the plastic maingear is softer so it is what gives. This is why almost all the micro helis come with a soft black plastic pinion, and a stronger plastic maingaer, so that in the unfortunate event that the blades strike something (tree, wall, ceiling, ground, car, wife, etc), the pinion will shred instead of the maingear losing teeth. It is far more cheap and easy to swap out a pinion, then a maingear on most designs.

I haven't noticed any reduction in sound level since my most recient maingear change about 4 months ago. The last one I sheared off 3 teeth, flying at night in my front yard I didn't see the black radio antenna of the car I flew over (luckily it didn't land on the car, now I don't fly low over cars at night, hehe).

For comparison, you could compare the sound you're hearing to some videos, some good examples can be found at Duzi (manufacturer of hornet mods), click on the videos link, Video4 has a spoolup where the music doesn't drown out the gear whine.

-Kai

Thanks Kai again.

I actually already had that video, its amazing, one of my favoutrite heli videos!!!

Hmm, Im not sure, Its just that, the spool up of that H2 doesnt sound kinda 'wrong' Liike with mine, when I spool it up, it just sounds 'wrong'. A bit hard to describe, I dunno, its just like when you hear it, you can tell its not meant to sound like that...

O well, Ill see what I can do, Im sure I'll get it working...ermmm... eventually...

Thanks a lot, Duane

Hmm sorry to hear that it sounds that much different, there was another trick or two my father taught me about how to trace down mechanical sounds when I was a kid.

I'll warn you right up front it's going to seem kind of wierd.

You can take a piece of fuel tubing, and use it as a make shift stethoscope, find a piece of tubing that will fit just inside your ear , put it in one ear (not deep at all, kind of like an earbud headphone, infact if you have an set of broken headphones you can pull the speaker and glue the tube to a hole drilled in the plastic), put the other end of the tube up to where you think the sound is coming from, move the tube around to find where it's loudest.

-Kai

Thanks again Kai,

Yep, sounds wierd, but Im sure it will work!!! I will try it out soon!
I did try and listne to where the noise was coming from, seemed around where the pinion and main gear meet, but that was just by having my ear near to them, hopefully using a tube of somesort will be better!

Would a straw be alright? (As long as I dont poke it too hard, might come out my other ear, seeing as theres nothing inbetween to stop it...LOL )

Thanks, Duane

Yes, a straw would work, however you either want to find one of the bendy straws, or tape 2 straws together with electrical tape so that you can see where you are putting the other end, oh, and make sure to have the rotor blades off when you do it

Oh, and you can build up the end of the straw for your ear by using electrical tape as well. Straws inside of your ear can hurt, those plastic edges are sharp (not enough to cut, but enough to be annoying), I found that out one night at a bar when I drank too much and someone thought it would be funny to put a wet straw in my ear after I had dozed off at the table.

-Kai

Originally Posted by Kai_Shiden

Yes, a straw would work, however you either want to find one of the bendy straws, or tape 2 straws together with electrical tape so that you can see where you are putting the other end, oh, and make sure to have the rotor blades off when you do it

LOL, yeah, those blades may cause a few problems if I dont take them off first...

Duane