General HK450 tail or gyro issue, with Video

[kml.krk]

Hey everybody, I am new here but I have been into RC for almost a year. I started with a HH Champ, then moved to Parkzone Corsair, then I built my own Guillows Corsair, converted to electric, then I got into helicopters with Syma S107, then for Christmas I got HK450 GT Pro but in the meantime I decided it is not a best idea to learn on 450 so I bought E-Flite msrX. Also for the past year I have been flying both helis and planes with simulators (Clearview and recently Phoenix)

Anyways, today I finished building my HK450 - Tony's tutorial videos have been tremendous help so huge thanks go to him!!! - but there seems to be an issue with either tail or gyro. What happens is that the tail bounces back and forth and spins to the left. I made a video because I can't describe it precisely. When I did not have the training gear on it would spin left so I made a little adjustment to the subtrim but it did not help much, in fear of destroying the heli I mounted the training gear and you can see the result in the video:

[video=youtube_share;YVsEIkZ0dcc]http://youtu.be/YVsEIkZ0dcc[/video]

if you could watch it and give me some tips that would be great.
Thanks a lot in advance!
Kamil

 

[Tony]

Hey Kamil, glad you could make it over here. I responded to your issue on YouTube, but I will post it here as well.

This is a pretty common issue for beginners in the heli world. it looks as if your gain is just a hair too high. try lowering it about 5% and give it another go. if it's still doing it, lower another 5 and so on. Once it stops, go up by 1 until it does it again, then lower it back down to the last good setting.

Let me know if this helps.

 

[kml.krk]

Hey Tony, thanks for quick reply.
I tried what you recommended and I still have this issue. I must be doing something wrong
What I did was: on the radio I went to GYRO settings (number 5 on DX6i) and there were 2 values:
0: 65%
1: 35%

Exactly what you recommended in your video. I changed the second value to 30 then 25 then 20 then 15 but I did not have any effect of heli behavior, which is strange.
When I spool up my heli I have all switches turned away from me (low rates) with the exception of GYRO which is pulled towards me => 1

Everything else have been set up the way you show in the video. For my motor pinion I am using 13T but it should not make any difference though.

PS. On the HK450 GT PRO, it seems that the rudder mechanism is different and it should be set up in a way that when you push the stick right that mechanism moves right, unlike in your version where the mechanism moves left when you push the stick to the right. At first I had set it up the way you mentioned but I realized that my tail was actually moving in the wrong direction when I used my input...
I just looked at the video again and I am confused. I am thinking if I put on my tail blades backwards...? But everything looks fine when I manually spin the main blades, everything moves in the proper direction. If you can help me out that would be wonderful. If you need me to post another video or picture just let me know and I will post right away!
Thanks!

EDIT: On the tail, is the thin edge the leading edge or the thicker edge?

 

[Tony]

When you are editing the gyro settings, 0 to 50 is rate mode, and 50 to 100 is HH mode. Think of 50 as 0. The farther you get away from it, the more gain you are putting into the gyro. So when you go from 30 to 20, you are raising the gain, and when you go from 60 to 70 you are raising the gain.

Put you gyro switch in position 0 and leave the gyro setting at 65. Should stop your issue.

Make sure your main blades are rotating clockwise, and your tail blades are going counter clockwise when looking at them from the right side. And make sure your tail blades are installed the correct way. I'm sure they are, but not sure by what I saw in the video.

As for the slider, If I can remember correctly, when the slider goes right, it should move the heli nose left and vise versa. You will know when you get the gain setup.

 

[kml.krk]

I know that it will sound stupid but how do I make the tail rotor spin anti-clockwise? Cause looking from the same point of view as the video my main blades are spinning clockwise and my tail is spinning clockwise. But it is belt driven so I do not think there is way to reverse that....
You can see direction of spinning at the very end of my video above.

 

[kml.krk]

I think I got it. I looked at it and looked and spinned the blades and looked again and it seems that I twisted the belt 180 degrees... this would cause the tail to rotate the wrong direction. This solves the issue of my blades mounted backwards and my tail mechanism moving the opposite direction...
Wow, building such heli for the first time is harder than I thought
I will fix it tomorrow, it is getting late, or rather early

 

[Tony]

Wow, was I tired when I wrote that lol. Your head should spin cloclwise from the top, and the tail blades counter clockwise. If you think of it in a centrifugal sense, it will be picking up, not forcing it down.

To reverse the spin of the tail blades, you take the tail boom off, and rotate 180 as you said. Make sure to not over twist the belt or you will destroy it. Once you do that, flip your tail blades around, make sure your slider is moving opposite to the stick direction, and you are set.

 

[kml.krk]

I fixed the tail issue! Thanks so much Tony!
There were 2 problems: my tail was spinning in the wrong direction... And there was too much gain on gyro.
To fix the problem:
- I rotated my belt 180 degrees making sure it doesn't bind
- Flipped blades in the tail rotor
- Reversed rudder channel back to what was described in Tony's videos (stick left causes slider to move right)
- Decreased gain on Gyro to 52%, I was going in increments of 5% down and then 1 up, just like Tony suggested.

It was almost fine on 53% but the tail would still wobble slightly. It seems almost perfect at 52%. I will do more testing in an area where I can actually fly. Hovering 450 size heli indoors makes me nervous LOL
Here is a video of a new setup:
[video=youtube_share;yNuVnBHIBGY]http://youtu.be/yNuVnBHIBGY[/video]

Thanks again!
Kamil

 

[Tony]

That looked a lot better. I'm not sure that 52% will be enough gain though. In HH, that equates to 4% gain. Most are runnign 15 to 20, but if that is what works for you, run with it. Can't wait to see it outside.

 

[kml.krk]

Yeah, I have no idea why it has to be so low for the tail to hold properly. Could the LIMIT on the GYRO have something to do with that?
I have decreased the limit from default value of 100 degrees to about 85 degrees?

 

[Tony]

Limit is to be used so your linkage rod doesn't bind up. Set your travel adjustment to 100, and use that pot to adjust out the un-needed movement.

 

[kml.krk]

Thanks, that is exactly what I used limit for