Can Joystick Sensitivity cause Rotors to brake

[Gonzo01]

I know the Logitech G940 is a new joystick, but I was wondering if it could be responsible for some of my rotors snapping off. I have included a track from my first mission on the Deploy Campaing. You can fast forward to the 10:00 min part where you will see me just trying to smooth out the KA-50 after a left hand climbing turn.

 

I have my G940 profiler turn the X,Y axis down on the joystick to 30%. I did this due to lack of centering when using the force feedback. Some people have refered to it as slop in the 20% range of the stick. I am not saying that this is the problem, just wondering if it might be contributing.

 

Thanks,

Gonzo:book:

Edited March 20, 2010 by Gonzo01

[topdog]

Heh.. I tried playing it, took off, kinda, drifted left past the 2 trucks nearby, then promptly stacked and rolled around the ground into the fence... I'll try it again, I might have been overzealous with the fast-forward keys perhaps.

[topdog]

Still can't play it, same thing happening. Was it a couple of left turns / waypoints into the flight by chance, as you were climbing over a hill where the instructor says something about friendlies nearby checking on the wreckage?

 

If so, I've had a few crashes there either caused by some kind of turbulence + low height (~30-50m above ground on the hillside) + high speed or a bug. I was never quite sure if it was a real mechanical failure or I'd hit an invisible wall in the scenery - the effect was similar either way.

 

After routinely doing that about 3 times I figured I'll give it a wider berth, flew higher, and all was well.

[Frederf]

Seemed a bit wobbly but rather surprising that you had rotor collision where you did. I had RCtrl+Enter up and nothing seemed out of the ordinary. Dust protection was on when it didn't need to be which is a power draw and doesn't help any blade separation.

 

Some better altitude and airspeed discipline would've lessened the need for "catching up" as you did around that left hand turn. The high collective setting along with a little pitch up is seemingly what did you in. I wasn't looking exactly but any right rudder also hurts.

 

Looking again (10:00-10:02 is the rotor collision) the amount of right rudder input was tremendous. A high collective, climbing regime made that amount of right rudder problematic. I'd look into your rudder usage.

[Gonzo01]

I was using right rudder to stablized my heading drift. I wonder if the trim got added together, because, I do remember hitting the trim button about 2 seconds before it broke. all I know is that I have gone through a lot of blades.

 

Gonzo

[Garfieldo]

I think it was only your speed combined with the rudder. At high speeds the bottom rotor flaps up when going forward to balance out the asymmetrical lift. Even without the rudder input the blades were very close together.

And the rudder caused a change in pitch/speed and the rotor sliced each other.

Also you were very accelerating at a very high rate, putting extra load on the blades.

Somewhere it has been said that you should plan your flightpath 5 seconds ahead, always knowing what you will do next. That way you can avoid a situation like this, where you frantically try to gain speed to catch up with your flight. And this wasn't even a combat situation, it was just a turning point :music_whistling:

 

Coming from mechanical engineering I can give you this advice:

Know what types of loads you can exert on the blades (acceleration, pitch, speed, altitude, etc...) which result in different strains (torsion, bending, etc...) for the blades and try not to combine all of them in a single maneuver, because a combined strain is bigger than just the sum of the different types of strains.

 

I hope I could contribute a little, have fun :pilotfly:

[Frederf]

Yaw pedal was extreme in any case. Primary tool for changes in course is bank, get your lift vector pointed the right way. Keeping your speed up near best lift (130 kmph) takes a load off of brute collective yanking. A lot of limits were stressed at the same time (climb, collective, speed, yaw) which on their own would have been OK.

[Distiler]

Going forward with left cyclic and/or right pedal increases the chance of rotor collition.

Edited March 20, 2010 by Distiler

[Gonzo01]

Well, you all have given me good advise to think about the next time I fly. I will try to be smoother on the controls, as you saw this has been happening quite a few times and usually during nothing more than just trying to stabilize the helocopter.

 

Gonzo

Edited April 1, 2010 by Gonzo01

[topdog]

Glad you got your answers Gonzo. I was intrigued as to why I couldn't play the track (since everyone else was doing so fine) and I've found out now heh, was all my fault.

 

I have some trigger-based code I'm debugging at the moment and it was turning on the Alt Hold AP at the start of the track heh, so basically your pre-recorded flight was now at the mercy of fighting against the AP that wanted to stay on the ground... that's a definite :doh: on my part. May even be worthy of the Pikard double-facepalm.

 

I didn't even realise those commands would work prior to 'take control'.

[Gonzo01]

It would be nice if ED would just take a look at the Logitech G940 and tweak it so the stick does not flop around so much in the center. It needs to center properly. This would allow me to use normal setting on the Joystick that would reduce the number rotor blade collisions. How about ED think you can look at fixing the Logitech G940 to work properly with Black Shark???

[Frederf]

Is there LUA edit where you can get all nitty-gritty on the FF behavior?

[Gonzo01]

Not that I know of. The new G940 and X65F have much finer control and require the programmer to code to these new standards.