Swing at 1800 rpm, is right?

[nivaldin]

what's up guys,

My Fusion is swinging at 1800 rpm, at 2000 rpm is fine.

Someone already tried 1800 rpm or lower?
You guys can try this and tell me if is normal?

Thanks

[Carapau]

Im sure it will be fine at 1800. I know a chap who flies his Align 600 at about that head speed, maybe even at 1600. It doesn't make the heli quite so stable in the hover and it slows down the manoeuvrability of the bird otherwise it should work. Personally I would stick to nearer 2000. You can get flights of 6-7 minutes of sport flying at this head speed and the heli comes alive from 2000 rpm.

[nivaldin]

I think I found the problem. The foam under the mini-vbar was too soft. I just replace it with a more rigid foam and the problem gone.

I did just a little test at home and the swinging disappeared.
But I'll do a test at field later to confirm;

---------
I did a field test, and the shaking/swinging persists

[ke6d]

I ran mine at 1550 rpm before just for the fun of it. It is stable with vbar 5.2. You can hover and fly circuit but that is about it. I was able to fly for more than 10 min on a set of 6S 3000mA packs.

[Wh1teAfr1can]

if you have good enough collective management IE Matt Bottos he ran a e6/7 down to 1000 headspeed and was doing piro flips and hurricanes lol

[nivaldin]

Originally Posted by ke6d

I ran mine at 1550 rpm before just for the fun of it. It is stable with vbar 5.2. You can hover and fly circuit but that is about it. I was able to fly for more than 10 min on a set of 6S 3000mA packs.

I'd like to fly at this low rpm too, just for fun as you said.
But at 1800 rpm my fusion 50 is still doing a little shaking/swinging

Some suggestion to solve it?

Thanks

[JustPlaneChris]

Try greasing your spindle shaft / head dampers with silicone grease. If it still shakes, you may need softer dampers for such a low headspeed.

[ke6d]

Originally Posted by JustPlaneChris

Try greasing your spindle shaft / head dampers with silicone grease. If it still shakes, you may need softer dampers for such a low headspeed.

+1

[nivaldin]

Hey guys, what do you think of testing this 1800 rpm and tell me if your fusion will shake or not?

[im4711]

For the last couple of weeks I started try out a bit lower head speed on most of my fleet. fusion 50 I am playing with 1800. It actually is quite stable and has no vibration or shaking issues at all. Not sure yet if I may want to lower it further.

[nivaldin]

Today a friend o mine who has a new one 'fusion 50' without a crash, setup his heli for 1800rpm and his heli shaken like mine, its a little shaking at the skids.

So now... I feel alleviated, because my heli it's ok shaking at 1800 rpm.
tks

[Slyster]

Here's my heli at very low headspeed.. I don't know what headspeed... but it sure is lower than 1800rpm.. flies beautifully!

[ame]http://www.youtube.com/watch?v=rjRM9WRDvGg&feature=plcp[/ame]

[nivaldin]

Slyster, it's hard to ensure that this flight is at 1800 rpm or lower. You need to check it!

Now, how could you not to know which rpm is on your heli? are you not using governor?
When you use governor, you set the rpm in there!

[Slyster]

Yes I use a gov... but it is kontronik so it simply uses a flat percentage in the radio. I just moved flight mode 1 to 40% flat on day and liked it.. but haven't tacked it. But I think it's around 1500 to 1600rpm or so. I will check the next time I fly and post here. I can lower it more by the way.. I have.. but the tail would blow out.

[nivaldin]

Originally Posted by Slyster

Yes I use a gov... but it is kontronik so it simply uses a flat percentage in the radio. I just moved flight mode 1 to 40% flat on day and liked it.. but haven't tacked it. But I think it's around 1500 to 1600rpm or so. I will check the next time I fly and post here. I can lower it more by the way.. I have.. but the tail would blow out.

Nice man, will help us!!

- When you go check it, post together here your motor, pinion, main gear teeths and battery cells.

thanks

[JustPlaneChris]

Originally Posted by Slyster

Yes I use a gov... but it is kontronik so it simply uses a flat percentage in the radio. I just moved flight mode 1 to 40% flat on day and liked it.. but haven't tacked it. But I think it's around 1500 to 1600rpm or so. I will check the next time I fly and post here. I can lower it more by the way.. I have.. but the tail would blow out.

Audio analysis of the clip shows 1830 rpm.

[nivaldin]

Originally Posted by JustPlaneChris

Audio analysis of the clip shows 1830 rpm.

sound of clip? Oh man, it's not a good way to measure, trust me!
It must be done with heli in the ground and stick at 50% at the field.

[Slyster]

That would surprise me! I'll tack it after the holiday weekend.

[JustPlaneChris]

The audio analysis has proven to be accurate to within 50 rpm on my own videos, compared to the rpm I've set in my Castle governor. And I've verified those readings with an optical tachometer.

[ke6d]

Originally Posted by nivaldin

sound of clip? Oh man, it's not a good way to measure, trust me!
It must be done with heli in the ground and stick at 50% at the field.

Actually, it is a very good way of measuring frequency (speed) There are a number of tools out there including the vbar spectrum analyzer, Android/iPhone headspeed measuring tools use this technique to measure headspeed. Check out this page for info:
http://en.wikipedia.org/wiki/Discrete_Fourier_transform