catastrophic maiden with blade 450 fbl conversion

Blackwarrior

Blackwarrior

Member
Hi Paul, thanks for all your suggestions. When I got it all setup I ran it without the blades attached, got to half throttle and all seemed well, moved cyclic around and watched swash which appeared to move in all the right directions. No vibrations at all from it.. So put the blades back on the following morn and took it in garden.. There was nobody around at the time, wife was watching from bedroom window....I had no worries about hurting anyone, but certainly didn't expect to see what actually happened... I was extremely gentle with throttle and didn't touch cyclic prior to it jetting off skyward... Never touched throttle hold either..

My throttle curve in "normal" mode is 0, 56.5, 72.0, 72.5, 72.5

Hold is 10% throughout

Pitch curve in "normal" is 45.0, 51.0, 60.0, 73.5, 100

Hold is 42.0, 46.0, 50.0, 75.0, 100

I got these settings from the eflite user manual, but I've just seen an error with the pitch curve, I've got it set to 100% at full! and the manual is 91%.... I never reached anywhere near full throttle though so I'm uncertain this is the cause..??!!

Thanks for advice
 
Derek

Derek

Well-Known Member
Although your Throttle and Pitch Curves are slightly different from anything that I've seen a beginner use, I can't see anything wrong with them. Just slight variations. However, I have to disagree with the 10% Throttle Hold settings. Throttle Hold is meant to "hold" or "disable" the throttle. Most of us at RCH, including myself, have 0,0,0,0,0 on the Throttle Hold. That way when we flip the Throttle Hold switch, the motor will not spin up.

Good luck buddy!!
 
Blackwarrior

Blackwarrior

Member
Derek said:
Although your Throttle and Pitch Curves are slightly different from anything that I've seen a beginner use, I can't see anything wrong with them. Just slight variations. However, I have to disagree with the 10% Throttle Hold settings. Throttle Hold is meant to "hold" or "disable" the throttle. Most of us at RCH, including myself, have 0,0,0,0,0 on the Throttle Hold. That way when we flip the Throttle Hold switch, the motor will not spin up.

Good luck buddy!!
Click to expand...

Hi Derek, I've changed this to zero then. Although that doesn't account for why it suddenly hit the sky like a rocket...

I'm going to start the rebuild tonight, I need a safe way to test it though !! Maybe open a new thread on a safety device, maybe a test bed, seen a few on YouTube but some look pretty dam dangerous
 
Derek

Derek

Well-Known Member
The lazy susan would be a good way to test the helicopter safely. If you are interested, Tony, I can do a video for you that just shows how mine works. It was cheap to make but very helpful.
 
Blackwarrior

Blackwarrior

Member
Hey Dan, that's a brilliant idea of Derek's

Derek, I've just seen the the video Dan has posted, brilliant idea, I want one mate....lol
 
Blackwarrior

Blackwarrior

Member
Derek said:
Although your Throttle and Pitch Curves are slightly different from anything that I've seen a beginner use, I can't see anything wrong with them. Just slight variations. However, I have to disagree with the 10% Throttle Hold settings. Throttle Hold is meant to "hold" or "disable" the throttle. Most of us at RCH, including myself, have 0,0,0,0,0 on the Throttle Hold. That way when we flip the Throttle Hold switch, the motor will not spin up.

Good luck buddy!!
Click to expand...

Derek, if you have those throttle and pitch settings could you send me them please, I'd rather use someone's settings than the manuals..

Cheers
 
Lee

Lee

Well-Known Member
With your Radio setting for Pitch curve Linear (0,25,50,75,100) You should have a pitch range of something like -11º to +11º.
If this is correct, then adjust your pitch curve to 45,47,50,75,100 ( -2º to +11º)
This will give you a slight amount of negative pitch to hold the heli still on spool up, especially in windy conditions.

For Throttle curve A good Starting point is 0,40,65,65,65. The three 65s can be raised to 75 if the head speed is a little slow.
This means, in a hover, the helis altitude is only being affected by pitch change, not both. This gives you a smoother feeling hover, stopping the heli from bobbing up and down so much in the hands of the novice.

At this stage you are not going to use ID 1 or 2. So to save from any mishaps (knocking a switch by mistake) Copy the Normal setting to all Flight modes, so if you do hit the flight mode switch by mistake, nothing changes.

Before flying again, once all set up, you can Skype me on a video call and we can check 100% if everything is working in the right direction :)
 
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murankar

murankar

Staff member
The combination of pitch with 10% throttle hold is what could have done that. Now normally. If a heli is going to drift (in your case backwards ) its because of the swash not being perfectly level. In those most cases we are at a tail in orientation which means we are able to correct it almost automatically. When you don't correct it or correct in the wrong direction you get the tail to drop.

I am just trying to visualize what happened based on settings. This is just my hypotheses.

Sent from my LG-E980 using Forum Runner
 
Lee

Lee

Well-Known Member
Tony, If you can remember. What exactly did you do with the sticks when it went out of control.
Did you hit any switch? Or just drop the throttle?
I have reviewed the video, and up until the violent lift off, the heli is being pushed into the ground by negative pitch.
Then there is a sudden huge amount of positive pitch.
This could be a wrong setting, or it could be a linkage malfunction. I know there must have been some damage to the head, but is there anything suspicious that broke.
Links, swash etc?
 
Graham Lawrie

Graham Lawrie

Well-Known Member
Well safety aspect aside, and after reading the thread fully, get that video on You've been framed. An easy £250 in the bank.

Maybe my bad sense of humour but I wet myself when that bird flipped:)

Lots of good advice.
 
murankar

murankar

Staff member
In the panic it is possible that if he did hit throttle hold, not likely; and accidentally hit positive throttle instead of chopping the stick then you would have had that reaction. Also the head speed appeared to in crease also which would have accounted for the rapid lift off.

Sent from my LG-E980 using Forum Runner
 
stokke

stokke

Well-Known Member
I agree with Lee's observation. The heli spools to high headspeed and seems to have negative pitch until it shoots into the air. If I didn't know any better your pitch curve could have looked something like this 0-0-0-0-100
 
P

pvolcko

Well-Known Member
I'm thinking there was a servo reverse and/or correction direction problem. I saw something similar happen at our club recently. Unusual linkage between swash and blades resulted in reversed swash to blade pitch movement, despite leading edge control. Heli shot up like a rocket when the test pilot couldn't figure out when it wouldn't lift off as he applied positive collective. So he chopped the stick and hit TH. Shot up 20ft and then plummeted down in a blade stop.
 
Derek

Derek

Well-Known Member
Lee said:
With your Radio setting for Pitch curve Linear (0,25,50,75,100) You should have a pitch range of something like -11º to +11º.
If this is correct, then adjust your pitch curve to 45,47,50,75,100 ( -2º to +11º)
This will give you a slight amount of negative pitch to hold the heli still on spool up, especially in windy conditions.

For Throttle curve A good Starting point is 0,40,65,65,65. The three 65s can be raised to 75 if the head speed is a little slow.
This means, in a hover, the helis altitude is only being affected by pitch change, not both. This gives you a smoother feeling hover, stopping the heli from bobbing up and down so much in the hands of the novice.

At this stage you are not going to use ID 1 or 2. So to save from any mishaps (knocking a switch by mistake) Copy the Normal setting to all Flight modes, so if you do hit the flight mode switch by mistake, nothing changes.

Before flying again, once all set up, you can Skype me on a video call and we can check 100% if everything is working in the right direction :)
Click to expand...

I like and agree with everything that Lee posted here, Tony!
 
Admiral

Admiral

Well-Known Member
Just a thought, I've never had anything to do with the XYZ system, but I know on the BeastX & BeastX clones if you do not setup Pirouette Optimization correctly you can come to grief. The Blade 450 was basically doing a ground Pirouette when it went crazy could it be in the Pirouette setup ?? Just clutching at straws !!
 
Lee

Lee

Well-Known Member
There are two issues here Keith.
The piro on the deck, which is 100% a tail gain direction issue. He has already discovered, using my video, this was the issue.
The second is this hard positive pitch. We will get to the bottom of this, once he comes back from holidays LOL :D
 
murankar

murankar

Staff member
Yeah, definitely a tail correction issue. I saw that on the first spool up. The second issues is an enigma at this point. Untill we get some feed back its going up as unresolved. I cant wait till we figure out what the issue(s) is/are.

Sent from my LG-E980 using Forum Runner
 
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