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Old Nov 02, 2012, 01:00 PM
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kushal_22's Avatar
Kamloops
Joined Dec 2001
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My Blades are vibrating when i get to 3/4 throttle. below that they are fine. No chips dings or anything like that in em

Mal
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Old Nov 02, 2012, 01:11 PM
Time To Fly The Best!
heritageflyer's Avatar
Hills of Eastern Ohio
Joined Nov 2008
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Quote:
Originally Posted by kushal_22 View Post
My Blades are vibrating when i get to 3/4 throttle. below that they are fine. No chips dings or anything like that in em

Mal
Check the Feathering Shaft, probably bent. Or Gear slipped down Main Shaft some.
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Old Nov 02, 2012, 01:11 PM
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United States, AZ, Mesa
Joined Jul 2007
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Quote:
Originally Posted by kushal_22 View Post
My Blades are vibrating when i get to 3/4 throttle. below that they are fine. No chips dings or anything like that in em

Mal
Yesterday you crashed it, right? Could be a bent feathering shaft.
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Old Nov 02, 2012, 01:54 PM
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United Kingdom, London
Joined Oct 2012
76 Posts
woohoo just replaced my very first tail boom ever and it works!!!!!!!

I first plugged it in the opposite direction... When I powered it on and the tail rotor started moving the nano started turning
Inserted the plug in the other direction and the nano is up in the air again. I'm very proud at this stage

I do see a very little vibration at the tail end but it does not interfere with fly characteristics. The tail end just vibrates slightly. It is visible but I don't have to apply any trim what so ever to keep it nice in line so I don;t think it's a problem.
Is this type of vibration normal?
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Old Nov 02, 2012, 02:02 PM
2 Turbos...Nope 1 Big one
skeppley's Avatar
United States, PA, Lake Wynonah
Joined Aug 2004
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Great job on your first repair

Usually a vibe in the tail is out of balance main blades or a bent feathering shaft. Also check the tightness of the feathering shaft.
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Old Nov 02, 2012, 02:24 PM
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United Kingdom, London
Joined Oct 2012
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Why do people say the nano can take a beating... Or do have bad luck and crash bad....

After a crash I seem to fly normally but then after a few minutes some problems seem to occur... This time I get massive vibrations when I give about 50% throttle. If I go higher, the nano tips over to the left.

I cannot seem to find a bend shaft or anything... I do notice that I can move the shaft up and down with the big white gear at the bottom. I can move it a few mm up or down.

How can I easily check if the feathering shaft is bend? It's so small and it looks alright at first sight...
The main shaft also seems fine...

I do notice that one blade seems a little loose so I will tighten it and see if that fixes the prob.

This hobby is an emotional rollercoaster From very happy for my first repair to sad because the next crash brakes something else...

Oh well, that'll teach me to connect to my nano and understand the problems.


edit: woohoo and we have another success
It was indead the blade that was a little loose.
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Old Nov 02, 2012, 03:50 PM
Fighting Gravity
elgecko's Avatar
USA, PA, Red Lion
Joined Sep 2005
188 Posts
I find the bird extremely tough. I do fly over grass....
I've been doing my first flips with this heli. Been in the grass a lot. Getting better as I'm starting to fly the 3 minutes now without crashing. Flip it over keep inverted flip back and so on.
Blade should sell a version with grass stained blades....LOL

I have not bent my feathering shaft, thought I did when I first got the heli since I was not used to one this responsive and had it all over the place.
I think this is what I read... you can take the short black plastic tool that you get with the heli. Remove a blade and insert the tool into the blade grip. Spin the tool. If the shaft is bent the other blade grip will move up and down.
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Old Nov 02, 2012, 04:13 PM
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United States, AZ, Mesa
Joined Jul 2007
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Quote:
Originally Posted by Passero View Post
Why do people say the nano can take a beating... Or do have bad luck and crash bad....
Every helicopter crash is an extremely random event involving hundreds of force vectors in all kinds of directions. How those forces come to a stop makes a big difference. Since the Nano is light weight, all those forces are small to begin with, and usually not enough to overcome the strength of the parts - but sometimes it will. It's just bad luck, your heli is the same as the rest of them. BTW, that's why you shouldn't put too much value on comments from a single person saying they had a crash and didn't break anything. I've crashed a Trex 500 upside-down without breaking anything - but I've crashed that same helicopter on the skids and broke everything on it. So, you can't tell anything from single anecdotes (that is true of most things).

You can tell something about the durability from the sheer number of people who have dubbed the thing "durable" though - because it's almost all of us. I crashed my Nano 5 or 6 times before I ever got it off the ground, because I was using a bad battery. That is pretty good - and quite a few of us do have multiple-crash data.
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Old Nov 02, 2012, 04:14 PM
Which way is up?
stuball56's Avatar
Michigan, USA
Joined Mar 2008
686 Posts
Quote:
Originally Posted by elgecko View Post
Remove a blade and insert the tool into the blade grip. Spin the tool. If the shaft is bent the other blade grip will move up and down.
Yes, that is how to check for bent feathering shaft, with one blade removed. The other blade will move up and down if bent.
The Nano was my first heli ever, too hard for me to fly so now I got a MCX2. But, I crashed that Nano at least 30-40 times mostly into the wall or onto cement. Only thing broken is one body mount, and cracked fuselage. I broke the swash plate fiddling around with it, not from a crash. One of the ball links broke off.
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Old Nov 02, 2012, 04:25 PM
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Orlando, Fl
Joined Jan 2008
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I got my "Wild" upgrade kit from AstroidDesigns. Looks like I will be busy this weekend.
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Old Nov 02, 2012, 04:40 PM
Which way is up?
stuball56's Avatar
Michigan, USA
Joined Mar 2008
686 Posts
On the other thread I sub, a guy gave up and sold his Nano I am not going to give it up. In fact I have some new parts coming for it. But, I am shelving it for a while as I learn on something a bit milder. I envision the day when I can say, "I need more power!". For now, it's back to flight school. I've been sent back about 4 grades!
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Old Nov 02, 2012, 05:08 PM
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i812's Avatar
Joined Aug 2009
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Quote:
Originally Posted by jasmine2501 View Post
Every helicopter crash is an extremely random event involving hundreds of force vectors in all kinds of directions. How those forces come to a stop makes a big difference. Since the Nano is light weight, all those forces are small to begin with, and usually not enough to overcome the strength of the parts - but sometimes it will. It's just bad luck, your heli is the same as the rest of them. BTW, that's why you shouldn't put too much value on comments from a single person saying they had a crash and didn't break anything. I've crashed a Trex 500 upside-down without breaking anything - but I've crashed that same helicopter on the skids and broke everything on it. So, you can't tell anything from single anecdotes (that is true of most things).

You can tell something about the durability from the sheer number of people who have dubbed the thing "durable" though - because it's almost all of us. I crashed my Nano 5 or 6 times before I ever got it off the ground, because I was using a bad battery. That is pretty good - and quite a few of us do have multiple-crash data.
+1

Something else that doesn't get posted often:

Learning to fly a heli is less than half the skill required

Learning how to inspect and making the heli mechanically as good as it can be, is probably the more important skill to learn.

I recently posted this in the Mini CP thread:

Quote:
Originally Posted by i812 View Post
Anything that is out of balance and/or doesn't spin straight can cause wobble. Not in any particular order:
  • Bent Main Shaft - I'm not certain I've ever seen a bent CF Main Shaft (CF Main Shafts are more likely to split); however, it is very common to bend Metal Shafts. Below is a procedure someone posted in the CB100 (has a Metal Main Shaft and Metal Rotor Head) thread describing how to check for a bent Main Shaft while on the heli:
    I suggest you remove main blades and flybar and spin it up as slowly as you can get the main motor to turn. Once the motor spins back off the throttle a bit, it will spin even slower. The head button (round top of head block) is machined, and part of the head block so you can trust it to be true. If it wobbles, use a sharpie to mark it while spinning. then you can bend it "in frame" away from the side that got marked by the sharpie until you have zero wobble in the head button. Rember to spin the head / main motor very slowly, it's easier to see the wobble.
  • Bent Blade Grips - verify they are "bent" equally straight. Ideally they should both be straight; however it is more important they be mirror images of each other.

  • Bent Main Rotor Blades - verify they are "bent" equally straight. Ideally they should both be straight; however it is more important they be mirror images of each other, especially the closer the "bend" is to the root of the Blade (i.e. an unequal bend has more of an imbalance effect at the root of the Blade than it does at the tip).

  • Main Rotor Blades with CoG in different locations - Both Blades should have same weight, and more importantly have their CoG's located in the same location.

  • Bent Feathering Shaft - when I was a newbie I thought a bent Feathering Shaft would show up as Blade Tracking Error, until Livonia Bob explained to me that air resistance on the Blades will most likely force a bent Feathering Shaft to rotate and reposition itself from an up-and-down oriented bent Feathering Shaft to a forward-and-backward bent orientation; and therefore will not show up as Blade Tracking Error, but instead will show up as Blade Phasing Error which will show up as a wobble in flight (not caused by Blade Tracking Error). A couple different ways to inspect for bent Feathering Shaft:
    • With LiPo disconnected, remove one Blade, rotate remaining Blade 90* from normal straight out postion, and use Feathering Shaft removal tool to rotate exposed end of Feathering Shaft, and verify remaining Blade does not flutter up and down as the Feathering Shaft is rotated.
    • Remove Feathering Shaft and roll on flat surface (a flat sheet of glass), and verify no exposed air gap anywhere between the bottom of Feathering Shaft and flat surface as Feathering Shaft is rolled along the flat surface.

  • Bent Tail Rotor Blade - Both sides should be identical mirror images of each other, having the same pitch and be bent up-and-down the same. Generally, the more both sides of the Tail Blades are not equally bent in pitch and/or length, the louder they sound.

  • Bent Tail Motor Shaft - can be inspected the same way as a Main Shaft

  • Improper Swashplate-to-Blade Grip Link Adjustments - ideally if nothing else was bent, they both should be the same length, but more importantly they should be adjusted for minimum amount of Blade Tracking Error.

Besides observance of wobbling in flight, a quick top level system check to verify most of the rotating parts are in balance is to do a Blade Tracking Error inspection. Although the top 2 Links can be used in almost all instances to adjust and minimize the amount of Blade Tracking Error, the smoothest flight would probably result from making sure all the above listed parts are "balanced" as best as possible before doing the Blade Tracking Error link adjustments. In other words, if all the other parts were equally bent to be mirror images of each other, then the top 2 Links should be adjusted to have equal lengths which would result in both Blades having the same pitch.
I think everyone would agree that learning to use the Throttle Hold switch before a crash is probably the most important lesson to learn.
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Last edited by i812; Nov 02, 2012 at 05:36 PM. Reason: Added Throttle Hold switch comment
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Old Nov 02, 2012, 05:20 PM
2 seconds from crashing
indoorheli's Avatar
United States, WA, Seattle
Joined Sep 2007
7,349 Posts
Quote:
Originally Posted by Passero View Post
Why do people say the nano can take a beating... Or do have bad luck and crash bad.
While what Jasmine says is true I also think there is a way to have a good and a bad crash With the type of flying most do it is easy to have a good crash on the mini/micro helis. Though the way some do extremely fast paced 3d almost any crash will be bad



Quote:
Originally Posted by jhroof View Post
I got my "Wild" upgrade kit from AstroidDesigns. Looks like I will be busy this weekend.
I just got my kit too. I however noticed two things....one i ordered the wrong one and two the mount is not offset like i had hoped but of course it is still a nice kit
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Last edited by indoorheli; Nov 02, 2012 at 05:27 PM.
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Old Nov 02, 2012, 10:30 PM
Safety : practice & promote!
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Joined Dec 2011
4,871 Posts
Just ordered mine. Should be here by the end of next week.

Sooooooo excited.

BTW, thanks for the insightful reposts, i812.
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Old Nov 02, 2012, 10:41 PM
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Joined Nov 2012
4 Posts
Hey everyone! So I'm fairly new in the whole hobby grade r/c heli field. I have had several cheapo coax helis, but a few weeks ago decided to step it up and get a nano cpx. I've had numerous successful flights (and crashes of course), but now I have something that I think the correct term is called the 'toilet bowl' effect. This all started about a week ago when I was trying to take off, and the feathering shaft nut somehow came loose, and one blade flew off. That was something I wouldn't have thought would happen... Anyway, I luckily found the nut and put it back on, and ever since then I have been having this issue. Basically when I move straight back and then let go of the stick, the heli either almost swings and rotates about itself (pivots about the top of the main shaft), or makes a large gradual loop (more of a U shape) to the right. At points it will move itself up to 4 feet over before it stops and hovers again. Moving forwards and strafing side to side I don't seem to notice this issue.

I haven't been able to find much info on this problem. So far I have replaced the main rotors, grips and feathering shaft, but it still does the same thing. My next thought is to replace the swash plate. Has anyone had any issues like this before? I don't remember it being like this since new, and it is a pain to do anything with precision as the heli has a mind of its own where it wants to go. I also recently have started with the vibration issue that people have reported recently, but that's the least of my issues right now. This toilet bowl needs to be flushed away! :P
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