New Micro Heli flyer needs lots of help - RC Groups
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Dec 03, 2001, 03:28 PM
Registered User

New Micro Heli flyer needs lots of help

Hi there. I have just started flying micro helis and have a hornet all built up. my first few hours were spent trimming the model and eventually replacing the tail rotor with a nice mod I go this heli.

Everything now is pretty stable... except this:

When I increase the throttle the heli requires a lot of right trim to stop it from sliding left accross the floor. I looked at the angle of the main rotor and its pretty steep just to keep it steady and hovering.

The next problem is when I increase the throttle to pull of the ground fully the main blades vibrate horribly and shake the heli all over the place. could that be because of the angle of the rotor head to hold it steady.

my question is why does it slide to the left when the head is level and why do the blades vibrate so much when I increase the throttle.

Also are all the helis so unstable. Also the rotor head is very flimsy as in I can move the blades around quite freely before the servo links hold the rotor head steady. Is that right? does that ake sense?

I also noticed my hornet would be all over the place constantly needing correction, not so much now I trimmed it but it was a bit difficult at the early stages. I am glad though that I can cope with it as I thought I would never be able to fly these things. looking good so far. just need some technical knowledge.

any help is greatly appreciated.

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Dec 03, 2001, 03:46 PM
Registered User
Some others with specific Hornet knowledge will need to repsond to most of your questions but I can handle the sliding to the left part. The tail rotor blows air to the right to compensate for the torque required to turn the main rotor. That thrust to the right makes the heli move left unless you trim it to the right - perfectly normal. The Heli will normally hover with a fairly pronounced lean to the right, maybe 5 degrees or so. Makes the instructions telling you to set it up with the swash level a little odd eh?
Dec 03, 2001, 03:51 PM
jbourke's Avatar
Did you properly install the anti-rotation arm on the main shaft?

Dec 03, 2001, 04:19 PM
Our Daddy and Heli Junkie
Fred Bronk's Avatar
Jamie, you can get the trim PERFECT and it will still want to fly all over. That is just the nature of the beast.
Sure it may stay in one spot for a moment or so, bu then it will wander off.

You will also notice it will fly better once it is around a foot or so off the ground, out of ground affect.

The vibration could be related to the sloppy head, but the sliding is normal. In fact the Picollo has dowels you tape to the skids till you get used to lifting it off.
Dec 03, 2001, 05:25 PM
Registered User


well thats great news about the sliding. I'm still a bit worried about the vibrations a high speed though. i'll try again tonight and update you on the specifics of the problem if i can.

many thanks guys.
Dec 03, 2001, 10:13 PM
misskimo's Avatar


well today , I test flew the hornet after being grounded for 6 months because I crashed it 2 times due to trying out a 010 that didnt have anough spunk , so this week I put the stock 300 back in a tried it out today , man this heli use to fly real stabile , but now Im all over the place too , but it just need tweaking again , it sounds like you have your antirotation arm in backwards , turn the big gear the way it suppose to go and see if the arm rides up against the servo linkage thats going to the top of the head , you know what I mean , I hope , another thing is , make sure your ball joints have a loose fit kinda , Tony
Dec 04, 2001, 12:29 AM
Registered User
Jamie, everything sounds kinda normal apart from the anti-rotation arm bit..If you turn the rotors clockwise by hand, the anti rotation arm should hold the links vertical and parallel to each other, Tony could be on the right track-make sure it is fitted correctly (I can send you a pic if you like)

Regarding the Sliding to the Left phenomenon we must live with, but you can minimise it by: Make sure CG is correct, when you take off you have to anticipate the left slide & give it a bit of right cyclic to compensate- you have to practice this. Upon taking off, just when the heli gets light, give it a good quick increase in throttle to get it up as quickly out of ground effect (a few feet) for more stability- soon you will not notice this sliding.

Does the shaking only happen when spooling up, then is ok once the heli is up? Blade Bolts must not be too tight or the blades will NOT self centre causing lots of vibrations. Make sure they are loose but not too loose- Should be able to hold heli sideways without collapsing. I also applied some Teflon/silicone lubricant around the blades & bolt and if any vibrations occur, they quickly dissappear....
Dec 04, 2001, 07:53 AM
Registered User
Hi John, I would really appreciate a picture of the antirotation arm as i did not build the heli unfortunately so I am not very clued up on the part names.

I have got used to the slidiing now but am still not able to get out of the ground effect because of that shaking. I will look at the anti-rotation arm tonight and the CG.

I'll get this if its the last thing I do..

Many thanks again,
Dec 04, 2001, 09:40 AM
Registered User
al_b's Avatar

Are you still using a carbon shaft? If so, this is probably causing your vibration problems. What to do is grab the head of the hornet, and main gear. If you can twist it more that about 10 degrees, then you will have to replace the shaft.

I would recommend visiting johnk's site, microhelis , and also the hornet-heli bbs.

Replace the main shaft with one from Walt (cyhyam).
See the hornet mods section of johnk's site, or visit DeeTee for most current upgrades.

As for the slide to the left, this decreases as you get out of ground effect.


Dec 05, 2001, 06:52 AM
Permanently banned
Mario's Avatar

Here is picture of mine, I use a double winged alum arm with a set screw for positive lock. Look also at the link below for more photos and info.

Dec 06, 2001, 09:09 AM
Registered User


This is exactly what is happening. I have the hover sorted out so we have no problems there.

I can get the heli to just lift off the ground with 80% throttle and it all looks good and stable but then when I put up the throttle to anything more the blades start to vibrate wildly and the heli loses control, battery falls out and I have to drop down to 80% to hold it steady again.

This can't be the ground effect can it as I tried to whack it upto 100% and clear the ground but it vibrates so much that the heli just can't climb and goes all over the place.

I don't thin there is anything wrong with the head set up since it is all perfect at 80. But then again I am new to this so any more ideas? should I get the mods mario was talking about to see if that helps?

Thanks again
Dec 06, 2001, 01:28 PM
Let's ride!
Jessdog's Avatar
Hi Jaime,

I hope I can help. Your're right, ground effect will not couse the heli to shake like that. What I would suggest is take the head off and balance it. Get 2 cups of equal length and place them a few inches apart. place the flybar on the cups and make sure the paddles are not touching the cups. Make sure the blades are extended and you will see them start to teter back and forth. What you want is the blades to be level. If one is lower than the other, put a piece of tape on the one that is higher until they are both level. Then you can take balancing out of the equation. Next, as someone else already mentioned, make sure the bolts that hold on the blades are not too tight. This is very important. Just loosen them up until the blades flop over with their own weight and tighten them up just a tad. Make sure you can move them with a little friction. This will allow them to straighten in flight and is likely the culprit to your problem. Last but not least, if you haven't already done so, get a metal/brass main shaft. Someone already mentioned that the carbon shaft may be split. Just save yourself some more trouble and get one of these. Since you are learning to fly, you will be crashing or hitting the blades on something which will definately split a carbon shaft but do no damage on the metal ones. Walt sells them in different flavors Actually different weight/thickness. I would suggest you get the thickest one. Less chances of you bending it.

Give this a shot and let us know what happens.
Dec 06, 2001, 06:48 PM
Registered User
jk's Avatar
i'd also recommend one of Walt's shafts ( he also makes areally cool a/r arm,(double capturing type)if you're looking for more info on them go here:
Steel Shafts

and here:

on my FP hornets, i always ran my blades pretty tight, but loose enough to fold if they hit something. most importantly though, they just have to be the same tightness.

hope this helps....
Dec 07, 2001, 04:56 PM
Aerial Shutterbug
RMihara's Avatar
Hey Jamie,

Hang in there, I too had bad vibes with my heli. Mostly caused by a bent main shaft. Only one to two thousandths caused the majority of 'wobble'.

I'd like to recommend these suggestions as well:

1. Check your main shaft for wobble/bent section.
2. The individual weights of your main blades.
3. Run up the head without the mains attached. Balance with the flybar weight(s).
4. Add the mains and run up again.
5. When you adjust the retaining/mounting bolts/nuts for the main blades, grasp each blade end in each hand and move for/aft at the same time. They should both move identically or you will need to re-adjust the stiffer (or looser) one to match the other.

Good Luck!