Heli wobble/shaking after take off

[lcc014]

This morning, I turned dial 1 (pot 1) on microBeast all the way down and removed training gear. Heli flied extremely stable, OMG !! I could do hand-off hovering with very very small drifting. One thing I observed was that heli had a couple tail wag in 3 minutes hovering. Should I lower TX gain of HH mode first or just go into parameter menu and make changes to get rid of this occasional tail wag ?

Thanks.

[Sonixs]

I had a similar issue and thought I could correct it via the Parameter D menu in BeastX and pot 3. After reading a post on the forum what I'd done worked but was not correct. So I set pot 3 back to 9 o'clock, set Parameter D to the lowest setting and adjusted the HH gain down until the wag/wobble was gone. Tested this by doing hard stops both CW and CCW. I then adjusted Parameter D up 1 level at a time.

If the Parameter D is set to high the tail will wander in a hover, and each time you set the Parameter D you'll have to tweak the HH gain slightly.

The sweet spot I found on mine is...
Parameter D - Red Flashing
Pot 3 - 9 o'clock
HH Gain at 60%

Flying with a DX6i, Align 205 Carbons, KDBB Tail Blades

With this I get a constant Piro rate in both directions, rock solid tail and hands free hover of 10 to 15 seconds depending on wind conditions.

I also bit a bit of grease in on the tail control rod where it runs through the slider mounted to the boom.


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[lcc014]

Originally Posted by Sonixs

I had a similar issue and thought I could correct it via the Parameter D menu in BeastX and pot 3. After reading a post on the forum what I'd done worked but was not correct. So I set pot 3 back to 9 o'clock, set Parameter D to the lowest setting and adjusted the HH gain down until the wag/wobble was gone. Tested this by doing hard stops both CW and CCW. I then adjusted Parameter D up 1 level at a time.

If the Parameter D is set to high the tail will wander in a hover, and each time you set the Parameter D you'll have to tweak the HH gain slightly.

The sweet spot I found on mine is...
Parameter D - Red Flashing
Pot 3 - 9 o'clock
HH Gain at 60%

Flying with a DX6i, Align 205 Carbons, KDBB Tail Blades

With this I get a constant Piro rate in both directions, rock solid tail and hands free hover of 10 to 15 seconds depending on wind conditions.

I also bit a bit of grease in on the tail control rod where it runs through the slider mounted to the boom.


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Thanks for the suggestion. I will give it a try.

[sutty]

Originally Posted by Sonixs

Following your posts on the servo resolution with Icc014 I expected you to be a lot more scientific and precise considering your knowledge.

Well yes, knowledge is one thing, knowing when it is necessary to apply it is another. For example, I never said I didn't make sure that step J wasn't precisely 6 degrees, and close to blue or that I didn't set my cyclic and pitch ranges just how I like them. I mean it is clear that balancing the blades will make the heli nice and smooth, but if it flies okay without, and it is just a cheap beater, which for me the 250 is, then I ask why bother?

Certainly on my 550 and 600 I am more than sufficiently anal about the whole thing.

Originally Posted by lcc014

Sutty, that was a great flight !! I also love the huge field for flying RC helicopter. I always balance the main blades and tried to balance 250 tail blades too. However, tail blades were to light to balance

Thanks for the detail explanation especially the car steering wheel analogy; very easy to understand and got right to the point.

Cheers, I'm very lucky to have such a nice field, and just behind me a simlar sized lawn over which I can fly. I like to fly over the field though as the long grass helps save the heli when I screw up.

Originally Posted by lcc014

This morning, I turned dial 1 (pot 1) on microBeast all the way down and removed training gear. Heli flied extremely stable, OMG !! I could do hand-off hovering with very very small drifting. One thing I observed was that heli had a couple tail wag in 3 minutes hovering. Should I lower TX gain of HH mode first or just go into parameter menu and make changes to get rid of this occasional tail wag ?

Thanks.

Great to hear your good results. Try turning pot 1 up a little at a time, you don't normally have to go right to the bottom, and when the shakes come back a little just back it off again. The reason I say this is that when you get too low on pot 1 you can lose that locked in feeling. If you think it is good now, if you can turn it up some more you will be amazed.

I think Sonixs is right that pot 3 is a waste of time for this very slow and very intermittant wag, as it doesn't seem relevant from the manual. Always left mine at default, and a lot of people do, with no issues. It does say in the manual that HH gain being too high, parameter D, can cause this, but I run HH gain at its highest on the 250 and do not have the issue, so not sure what it going on there. In my experience, and I have seen it a number of times both on my helis and on others, is that odd, very intermittant twitchy tail behaviour, where one minute it holds, and the next it moves and then holds again, has nearly always come down to the tail mechanics not being perfectly smooth. Look for possible sources of binding, and follow Sonixs' suggestion to lubricate, the guides, but also make sure the grips are completely free and lubricated too.

Rather comically, considering my previous posts about my lazy attitude with the 250, sorry about that, drifting off topic, it can also be brought about by vibration. I knew there would be a reason for balancing those blades.

Can even be caused by a slightly bend tail shaft, though I've flown with bent ones of those before now and not had an issue. Sometimes it gets you, and sometimes it doesn't, I guess it is all about frequency.


Cheers

Sutty

[lcc014]

Originally Posted by sutty

Well yes, knowledge is one thing, knowing when it is necessary to apply it is another. For example, I never said I didn't make sure that step J wasn't precisely 6 degrees, and close to blue or that I didn't set my cyclic and pitch ranges just how I like them. I mean it is clear that balancing the blades will make the heli nice and smooth, but if it flies okay without, and it is just a cheap beater, which for me the 250 is, then I ask why bother?

Certainly on my 550 and 600 I am more than sufficiently anal about the whole thing.



Cheers, I'm very lucky to have such a nice field, and just behind me a simlar sized lawn over which I can fly. I like to fly over the field though as the long grass helps save the heli when I screw up.



Great to hear your good results. Try turning pot 1 up a little at a time, you don't normally have to go right to the bottom, and when the shakes come back a little just back it off again. The reason I say this is that when you get too low on pot 1 you can lose that locked in feeling. If you think it is good now, if you can turn it up some more you will be amazed.

I think Sonixs is right that pot 3 is a waste of time for this very slow and very intermittant wag, as it doesn't seem relevant from the manual. Always left mine at default, and a lot of people do, with no issues. It does say in the manual that HH gain being too high, parameter D, can cause this, but I run HH gain at its highest on the 250 and do not have the issue, so not sure what it going on there. In my experience, and I have seen it a number of times both on my helis and on others, is that odd, very intermittant twitchy tail behaviour, where one minute it holds, and the next it moves and then holds again, has nearly always come down to the tail mechanics not being perfectly smooth. Look for possible sources of binding, and follow Sonixs' suggestion to lubricate, the guides, but also make sure the grips are completely free and lubricated too.

Rather comically, considering my previous posts about my lazy attitude with the 250, sorry about that, drifting off topic, it can also be brought about by vibration. I knew there would be a reason for balancing those blades.

Can even be caused by a slightly bend tail shaft, though I've flown with bent ones of those before now and not had an issue. Sometimes it gets you, and sometimes it doesn't, I guess it is all about frequency.


Cheers

Sutty

Sutty,

Thanks for the suggestion, I will turn up pot 1 one click at a time and see. Fort the intermittent tail wag, the whole tail assembly is new including tail blade holder, slider, tail shaft, etc. I did use grease to lube the shaft and slider during the assembly. I think I will play with TX tail gain and see what happens. Otherwise, I will follow Sonixs suggestion to lower the HH gain in BeastX, Parameter D, and check.

[Sonixs]

Something else to consider, if its applicable in your case Icc014...if your running a TT their may be some vibrations caused by the bearing being slightly off set within the boom...not necessarily blades being out of balance a recovery for Sutty.

I've not had this issue but I've read on other forums that this has been a potential cause for vibes and unwanted tail behavior.

What do you think Sutty?

I will say though that the TT has given me better tail behavior than the original SE belts.


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[lcc014]

Sonixs,

I am running new Kevlar belt in my 250. So vibration caused from TT is not an issue here.

Thanks.

[ahahn]

Originally Posted by lcc014

Thanks for the suggestion. "All the way", did you mean to about "6 o'clock" position ?

Yes in my case I ended up at the 6 o'clock position. It is possible i could sneak it up a smidge or so, but it flies ok as is. Note that 6'oclock isn't "off", it is just the lowest gain via the pot setting. Not sure if I could get even lower via the PC software, but anyway at that location all my wobble went away.

[lcc014]

Originally Posted by ahahn

Yes in my case I ended up at the 6 o'clock position. It is possible i could sneak it up a smidge or so, but it flies ok as is. Note that 6'oclock isn't "off", it is just the lowest gain via the pot setting. Not sure if I could get even lower via the PC software, but anyway at that location all my wobble went away.

Thanks for the clarification. I also turned the pot all the way down to stop position. Now, I will turn it back up tiny bit at a time to a point before wobble happens again.

[lcc014]

Last night, I turned up TX tail gain (both HH and rate modes) to a point at which one click lower than "G". I also turned up the pot 1 dial to about 7:30 position. I hovered the heli for 5 minutes with no wobble and no tag wag.

Many thanks to all the helps from this forum

[Sonixs]

Icc014...Glad you got the bird all setup and stable. Enjoy the flying now...


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