Under 2.0 vibes on 700N and HUGE pics

[ZzEther]

Let me qualify that just a little. Right on lift-off the vibes spiked to 3.4 but once in the air they were pretty steady around 1.4 to 1.8. The landing is what really gets you, as soon as the heli touches the ground coming down, it jumps to around 7 for a second then settles around 3 to 4 again. Then, when you pull the collective back to idle down and approach the heli, it shoots up over 8 while the blades spin down.

Maybe if you hit throttle hold and let the blades spin down without putting them in negative pitch that would keep it from jumping up to 8. But who cares really, if you're on the ground you're done!

I'm going to post some pics of how I mounted my setup. I wanted to avoid using the towel method (GERGOB!) but believe me, I would've if I had to! Also, I did NOT use the power bus! I have a feeling I'm going to hear about it and I'm aware of the dangers. When the heli goes in because of a brownout, I will just rebuild it. My priority is a power switch and push-button ignition. When the regulator wrecks one of my birds, well maybe I will change my behavior then. And vibration? Well zip-tying the wires to the frame with a little slack worked on my 360 and I went with that method here. I admit, I might be able to knock a few points off my vibe score with the power bus, I'm just not that concerned.

But I have to tell you, as little faith as I put in Align electronics, I have three 2-in-1 regulators on three helis and never have I had a brownout, even on the flybarless birds. I don't know if it's any indication, but my sk720 flight logs the voltage was always fine and flickering between 5.6 and 5.7 volts. Not sure if that means anything, but there it is. I used to insist on 2s to the cyclic until I installed a 2-in1 on my 600N and couldn't tell the difference. I'm not that good a pilot!

One final thought, all I got to do today was a few stationary flips and rolls and a couple big-sky loops. I sat at the field waiting for 40 minutes to get the bird in the air and when the rain stopped for 10 minutes, I rushed out and flew. That was all I could do. I can get the blades barking pretty good coming out of a tail slide and I'm curious to see where the vibes go. But this was the sk720's maiden and I only had a few minutes.

One final, FINAL observation. It was cold and moist out and my engine was running like total CRAP, really sputtering and burping hard. And my blade tracking was WAY off, like 3 turns off! I'm not sure how that happened but I think it might have something to do with me finishing the 720 install at around 4:30 this morning!

Sorry for all the TEXT, this is how I attacked the nitro-vibration issue:

[ZzEther]

The problem with Zeal tape is that it will twist under whatever is mounted to it. It is solid enough in pitch and roll, but it will yaw under anything. I
mounted my sk360 on Zeal and strapped it down tight but there was no tail gyro in the 360. People will tell you not to use zeal tape under a gyro
and for good reason. But what if you had zeal on THREE sides?

This is the 3-in-1 off the first heli I ever flew, an EF Sabre. I took it apart, dremeled out the long sides and any pieces that stuck out anywhere and
loaded it with zeal tape. Only halfway up on the 720 because there's connectors for satellite RXs and GPS and what not, but halfway is plenty to
keep it from yawing:




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[ZzEther]

The sides of plastic "box" are a little bowed out and need to be reigned in with a strap. Unfortunately it's not real easy to mount the
720 front-to-back on the heli on the stock gyro mount and you need it sideways. That means the straps can't go sideways or you'd
be strapping down onto servo connectors and blocking your usb port. I chose to cut an already thin Align strap lengthwise down the
middle and make two even narrower straps and then drill holes in the receiver tray for them. It was actually pretty easy, you can drill
right through the thing, one hole on each side of the center support line:



Then run some straps under and tighten 'em down:



And here it is all nestled in it's zeal bed. never mind the cat hair!



This is where I strapped my wires, I'm thinking about replacing the fuel tubing with zeal tape somehow, I don't know. Maybe I'll just go fly the darn thing.

[OICU812]

I guess as a question, how are you certain that the bottom of the unit is in fact square to the bottom sufrace and also that the unit is central square with frame? On any FBL unit the module or gyro as here should be known as flat and also perfectly square, this will affect phasing as well as odd flying with either the ele/aileron surfaces...

Just curious as it just looks compressed on the Zeal is all and off square...

[ZzEther]

Originally Posted by OICU812

I guess as a question, how are you certain that the bottom of the unit is in fact square to the bottom sufrace and also that the unit is central square with frame? On any FBL unit the module or gyro as here should be known as flat and also perfectly square, this will affect phasing as well as odd flying with either the ele/aileron surfaces...

Just curious as it just looks compressed on the Zeal is all and off square...

I see what you're saying and let me assure you it's all in the pictures. None of the pictures I took are square on the side or top, which I just noticed.

It is possible to wrench zeal down on one side or the other and get it distorted but if you deal with the whole block of zeal and press straight down
on it, it has no tendancy to "squirt" out from under anything.

My less-than-stellar cutting of the zeal tape isn't helping how things look I'm sure. Those jagged edges might be making it look less than square also.
It really is a cool tape and if you don't get all crazy with one edge of it everything is good. To tell you the truth I never even thought about it. All I did
was stand over the heli and drop the 720 down as square as I could with the frame support. I didn't even think about squaring the bottom of the 720
with the gyro mount/frame. I could adjust the front/back tilt by adding or subtracting tension on the straps but it looks dead on to me, I hope the picture
does it justice. With all that lack of thought, this is how things came out:



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If there is enough askew to throw the unit off, I can't feel it. Or at least I couldn't in the 10 minutes I flew it. It flies amazing and has low vibration levels. It's exactly what I paid for!

Ignore the cat hair, if I could be rid of them I would!

[ibflyen]

Im by no means am an expert on FBL but with the vibration numbers you are showing this seems to be the best setup i have seen yet!
Like i said im no expert but to get those kind of numbers is impressive and i will darn sure be trying it!

Im pretty sure your setup will be a lot more true to square than wrapping it in a beach towel and strapping it on top of the frame as i have seen posted elsewhere on here.

[ZzEther]

Originally Posted by ibflyen

Im pretty sure your setup will be a lot more true to square than wrapping it in a beach towel and strapping it on top of the frame as i have seen posted elsewhere on here.

Gergob got his vibe levels down to 1.9 which is pretty dang good, the towel works!

Originally Posted by ibflyen

Im by no means am an expert on FBL but with the vibration numbers you are showing this seems to be the best setup i have seen yet!
Like i said im no expert but to get those kind of numbers is impressive and i will darn sure be trying it!

Man I hope you're right but these are very preliminary numbers, I wouldn't order a case of zeal tape just yet. One thing I'm worried about is head speed. I didn't write down or copy my model before I got the 720 and when I started the install I was a little excited and just cleared the model memory so my head speed is low. Or at least it felt low, the engine wasn't running real good in the 40 degree, wet weather yesterday. I need to get the tach out and get the governor set up again.

The other thing that scares me is this was a pretty basic flight. I'd like to see what something like a tic-toc does, especially MY tic-tocs. I'd also like to see what happens when I get the blades popping coming out of a tail slide or even a backwards loop. I can get some good noise out of them if I let the last part of a backwards loop hang for a second before finishing it.

What I would really like to do is put up a video of a flight and upload the log file to go with it, I'm sure you can watch other people's log files. If it ever quits raining here I could put some more time on the thing!

[OnTheSnap]

Keep in mind that vibe scores less then 7.0 are only for getting bail out to work and logging. Make sure whatever mounting method you use doesn't sacrifice on performance, which for me is the number one priority.

[ZzEther]

Originally Posted by OnTheSnap

Keep in mind that vibe scores less then 7.0 are only for getting bail out to work and logging. Make sure whatever mounting method you use doesn't sacrifice on performance, which for me is the number one priority.

Agreed. But I like messing with stuff like this. Sometimes when I have my fleet dialed in and all there is to do is fly them, I get a little bummed out. I like to tinker with things.

You think zeal tape is affecting the performance somehow? I can't see how but I never object to being enlightened on things.

[OnTheSnap]

No clue, haven't used it. But The "squareness" of your installation doesn't look perfect. But if you like the way it flies, then it's all good!

[ZzEther]

Is this what you mean?




I can pull that down a titch with the straps but you have good eyes, that looked square to me.

[OnTheSnap]

Perfection is just an option. If it flies well it's all good. Depends on your OCD level. I think most Helifreakers are pretty high on the OCD quotient though.

[Canadaheliguy]

[QUOTE=I think most Helifreakers are pretty high on the OCD quotient though. [/QUOTE]


Now there is a statement I will 100% agree with!!!!!

[blade strike]

Originally Posted by OnTheSnap

Depends on your OCD level. I think most Helifreakers are pretty high on the OCD quotient though.

Shhh.... Dont talk about that, remember?

[BobOD]

Originally Posted by Canadaheliguy

Now there is a statement I will 100% agree with!!!!!

Don't you mean 99.99%

[badbill]

What did I miss or read wrong in my instructions... I thought it had to be mounted with the wires coming out either front or back, and that sideways wouldn't work?