Take Off Tip-Overs & Proper Setup

[02ViperTwin]

Hi Everyone,
Like a few others I’ve read about here, I had two take-off tip-overs during my first flight that I am hoping were just due to my overcorrecting. Fortunately, I only scuffed both sets of blade tips (replaced both sets to be safe), but I wanted to confirm a few things before I try flying again…

Given the main shaft is canted forward in this heli, where should the CG be set with respect to the leading edge of the landing skids (using a fulcrum under the skids technique)?

In a hover, do the skids or tail boom end up being parallel to the ground?

After the heli is initialized, should the swashplate be parallel to the ground or parallel to the main gear? Mine appears to initialize parallel to the main gear (not parallel to the ground). Is this correct?

Thank you very much in advance!
Don

[mingledorffw]

Hey Don. I haven't had a tipover or even a wannabe tipover for awhile now, thankfully. Couple things which I think have helped. I raise throttle to mid stick, 0 pitch, pretty quickly. Not super fast but once I initiate throttle I get it to midstick fairly quickly. I believe in my first flights I may have been lingering a little to much getting it to mid stick. I'm at midstick about the time it fully spools up then I lift off with no issue. The other thing is I take off and land on the hardest, most level spot I can find. I also did a good and thorough trim flight early on as well. When landing Ive been hitting throttle hold right at skid touch down or a little before.

I'm pretty sure swash should be level with main gear/shaft on a tilted heli. The heli looks level to me when just hovering around.

[brianbremer]

Hi Don,

The tail boom, rotor disc and main gear are parallel with the ground in flight. The swashplate should be parallel to the rotor disc, main gear assembly and perpendicular in both axis to the main shaft.

Only the bottom of the frame and lg is canted, beyond that its a normal heli.

To check the c.g. you can carefully pick the model up by the center of the head block and the tail boom will be level when the weight distribution is correct. Keep in mind the battery and canopy needs to be installed to check the c.g.

Always make sure you put the heli on the ground facing into the wind, placing the model in a direction that allows the wind to blow under the disc will lead to problems.

Always make small corrections while the model is still on the ground, its far easier to make the same corrections 3-4 times if needed than it is to compensate for 1 over correction.

Once you start the blades spinning get the collective up near mid stick or near 0 degrees, holding negative can lead to a lot of vibration and ground resonance resulting in you having to make more corrections during takeoff.

The Fusion 270 does have a soft start and will be up to speed in about 5-6 seconds.

Keep an eye on the disc, it should remain parallel to the ground until you lift off. Once clear of the ground make small corrections to bring the model into a still hover.

I do believe the "keep the disk level" is possibly the key some are missing. Since the c/f landing gear is extremely rigid they may not see the disc moving whereas the plastic landing gear would flex and show the movement in the airframe.

Stick to the normal throttle curve in the manual, 0, 45, 45, 45, 45 and do not raise this value. Stunt 1 and Stunt 2 can be adjusted by normal must remain at 45.

Best Regards,
Brian Bremer
Horizon Hobby, LLC

[02ViperTwin]

Hi mingledorffw and Brian,

Thank you very much for your informative responses!

Now, I’m sure I’m overthinking things, but may I ask a few more questions?

It makes a lot of sense that a heli should hover with the rotor disc, swashplate, main gear assembly, and – for the Fusion 270 – tail boom all parallel to the ground, but then this will make the tail fin contact the ground first when landing, yes? Doesn’t this cause issues with the gyro until the skids hit the ground? Maybe this is why mingledorffw has better luck hitting throttle hold just before touchdown?

During spin-up, isn’t the rotor disc actually still tilted slightly forward due to the canted frame and landing gear? I will definitely make sure it is level side-to-side before lifting off.

For the AR636A, is there any difference between initializing it when it is perfectly level (as when the heli is in flight) or slightly canted (as when the heli is sitting on its skids)? Just curious what the unit is doing to set the servos in their correct positions.

Thanks again!
Don

[Kamisamaa]

Hi friends. I have Blade 270 Fusion and DX6e
I set it like on the included instruction, but i can not even take off...
This is my first Heli and i never fly before (just 3chanel heli)

Can you help me?

What is wrong, what can i do to fly?
on Normal mode i can push trhrotle maximum, and heli do not take off :S this is normal? i must change to mode 2 for take off?

Look at my radio settings -

VID 20180429 160230 (2 min 29 sec)

And try take off (just on normal mode) -

VID 20180428 092840 (1 min 23 sec)

[Chris g.]

It sounds like your pitch is revered. Go back and check that setting in your radio.

[mingledorffw]

going off my own RC flying experiences/mistakes from when I started, I would shelve the 270 for now, and get something like the 230s or mCP s.... if your coming from 3 channel helis strait into collective heli's. Work on your transmitter programming skills and flying skills with those, then you'll have that more advanced 270 to step up too. Just my advice, not trying to be critical of you and your 270 decision. Good luck.

[Rev600ho]

Mingle is correct, that is a very aggressive heli for a first and does not have the "stablility mode" to save the day for you. A 130S or 230S is much easier to fly and less intimidating for a first heli.

If you need to fly the 270, try to find some local help to test fly it for you, make sure they are experienced.

[Kamisamaa]

I have o lot of hobbys, and more dangerous Now i wanna try flying RC but i do not like drones. I thought that the 270 model would be a good for start :S
I do not want to do aerobatics right away.- just normal fly - later maybe I would try something.
-------------------------------------------------------------
My servo settings - pitch are not reversed. ->

VID 20180430 155243 (0 min 58 sec)

Could anybody say when the helicopter should rise? [what throtle position, pitch, gyro]

May someone can send me right settings too? (for SD card)

[2005h4]

Few basic things u can check.
Move throttle stick up, the swashplate should go up. If it’s opposite reverse the pitch. But If it’s correct, than look at the main blades. The thickside of the blade should slowly go up as the swashplate move up.
Don’t look at the tx numbers – or + and assuming it won’t work. u need to actually try to spool up the heli. Also blade should rotate clockwise. If it’s counterclockwise than reverse the red, and blue wire from the motor.
Throttle stick at midpoint is zero deg pitch. Above midpoint, it’s a positive pitch which heli should start to lift.

[Lotus 7]

Originally Posted by Kamisamaa

I have o lot of hobbys, and more dangerous ....... I thought that the 270 model would be a good for start

A 270 class heli may not seem like a particularly large model and as such may not look very dangerous. However it deserves respect, 270mm carbon fibre blades rotating at over 3000rpm are as dangerous as it gets.

I'm sorry my friend but I cannot in all honesty say the 270 is a good choice as you're first CP helicopter. The experience you had with the 3ch model would teach you very little about collective pitch.

If you have been practising regularly on a sim for some time then maybe you could start with the 270. If you have zero experience with collective pitch flight then I would consider something at least a little smaller, lower headspeed and plastic blades. The 230S is a good option as has been mentioned.

Please trust us on this. If you have no experience with CP and no sim experience and you try to fly the 270, you will crash.

Whatever you decide I wish you well. Stay safe

[drparker151]

Take safety out of the conversation, for now, they are right by the way.

You will crash your first CP multiple times and it will get expensive with bigger heli's .

[-=RAGE=-]

Hello,
just a few words about my tip over/tilt experience.
Due to damaged antennas of my AR636 unit, my dealer replaced it by a brand new one.
I've installed the new original Fusion 270 AR636, did the servo adjustment, the swash plate was perfectly aligned and did the recommended trim flight. In the meantime, I've learned, that the trim flight also includes the calibration procedure.
After the first trim flight, I've observed a tilt to the right behaviour. Controllable, but unpleasant!
After that unsatisfying trim flight, I've decided to repeat it.
During this second trim flight, my control inputs, to correct a slow drift to right and backwards, were more courageous. After the required flight time, I've landed my Fusion 270, turned of the motor and activated the panic button to exit the trim flight.
Now, I did not restart the motor for the test flight, I've dis- and reconnected the battery and voila, the take off was completely free of any tilt tendency!

Now, 35 flights later, I've never observed that unpleasant tilt behaviour again!
My Fusion 270 takes off as I'm used to my other flybarless systems, like the VBar or the MicroBeast.

[brianbremer]

Hi Rage,


The trim flight does not include the calibration procedure, just trying to avoid incorrect information floating around.


The trim flight will only help the panic return to level levelness'es and may help continuous piros to remain flatter.



Due to a bug in the fusion 270 firmware you cannot run the calibration procedure, but since the calibration was performed correctly at the factory you actually don't need to run the calibration.


I suspect something else may of changed on your model helping to resolve the issue, could even be something as simple as a tight spot in the gear mesh wearing in.



If you are seeing drift in normal, st1 or st2 in a hover chances are it is being caused by vibration and I would recommend hunting down and resolving vibrations.



Best Regards,
Brian Bremer
Horizon Hobby, LLC

[Thomas.Heiss]

Hi Brian,

Originally Posted by brianbremer

I would recommend hunting down and resolving vibrations.

Wouldn't this be a bit easier to check and resolve this if the AR636 FBL would support logging (so you can read values after 1-n minutes) and maybe bring a vibration analysis with it which could be used to read all the sensor values over a computer software application or mobile app, e.g bluetooth, USB cable, etc.?

Shouldn't the modern sensors support analysing vibrations anyways like many other FBLs do already?

Well, I am just thinking load, what would be my personal wishes if I go for FBL conversion on my Blade 450.

Viele Grüße

[-=RAGE=-]

Originally Posted by brianbremer

Hi Rage,


The trim flight does not include the calibration procedure, just trying to avoid incorrect information floating around.

Hello Brian Bremer,
thank you for clearing this up.
My conclusion was based on this post:
https://www.helifreak.com/showthread...57#post7559524

Originally Posted by brianbremer

Due to a bug in the fusion 270 firmware you cannot run the calibration procedure, ...

Can we expect a firmware update?

Originally Posted by brianbremer

I suspect something else may of changed on your model helping to resolve the issue, could even be something as simple as a tight spot in the gear mesh wearing in.

The drift disappeared right at the moment, as the successful 2nd trim flight was finished.
I'm a professional watchmaker. Adjusting a perfect gear mesh is part of my job.
Please believe me, there was no tight spot or something else.

Originally Posted by brianbremer

If you are seeing drift in normal, st1 or st2 in a hover chances are it is being caused by vibration and I would recommend hunting down and resolving vibrations.

The flying of radio controlled helicopters is my passion since 1997. I'm familiar with lot's of possible problems, which my appear in this great hobby. Vibrations are one of that.
Sometimes it took longer, but I've always found the solution.

My Fusion 270 mechanic runs smooth without any vibrations. With or without blades.
I've also tried the Mikado Mini VBar, where the tilt/tip over behaviour never happened.
The reason for the slow drift to backwards may be the battery, which has a weight on the lighter side. But in 2018, I expect a flybarless system which can compensate a few grams of tail heaviness.
And the AR636 managed it with distinction - after the 2nd trim flight.

As a last word:
It's great, that some of the manufacturers and their employees read in forums and try to help.

Best regards from Germany,
Bert

[2005h4]

So, basically u did the trim flight, and tip over tendency is gone?? As u know mine tipped over 2x in separate occation, and lost 6 servo’s. I’ve never got anywhere with stock heli. Not even able to spool up.
When u in trim flight mode, the heli will lift right up because of safe mode??

[-=RAGE=-]

Originally Posted by 2005h4

So, basically u did the trim flight, and tip over tendency is gone??

Yes

Originally Posted by 2005h4

When u in trim flight mode, the heli will lift right up because of safe mode??

No. The Fusion 270 has no safe mode.
The tilt to the right behaviour might be not as pronounced as yours. My take off was on the faster side. Once in the air the behaviour of the heli was much more relaxed.

[2005h4]

Ok…thx Bert. Let me try one last time. This is going to be my 3rd try.

Mark

[-=RAGE=-]

Please have an eye on your swashplate. It should stay perfectly level and the heli should run smooth without any vibrations.

Here in Germany we say (translated):
All good things come in threes.