dknovick
Posts: 727
Joined: 1/19/2005
From: Albuquerque,
NM, USA
Status: offline
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quote:
ORIGINAL: helojerry
I've been wanting to write more about the yaw ratre gyro, but haven't had the time. In my thinking, "gain" and "proportional" mean the same think. If I write
y=kx
it means that "y is directly proportional to x" and we could say the k is the proportionality factor or "gain."
True, but I believe that UTM was referring to changing the gain on the gyro input as opposed to adding more offset to the tail. Based on my (and others) observations, the tail is controlled by this equations:
tail = k1*main_motor + k2*gyro + offset
where:
k1 = proportional gain from the main_motor (most likely less then 1)
k2 = proportional gain from the gyro
offset = user input (from the trim tab) to stabilize the yaw (keep the nose pointing straight with "hands-off" )
(this is assuming that it's just P control and not PID [Proportional, Integral, Derivative], or PI, or PD  )
or even Fuzzy Logic! 
So the question is, does the pot change the "offset", or "k2"
quote:
ORIGINAL: helojerry
One of the things that makes it so difficult to figure out what is really going on with these pot settings is that there are so many variables to consider. To start with, every helicopter is going to behave somewhat differently right from the factory because of the level of quality control applied to a mass produced item like the F40. Then add on top of that the mods, repairs, and fixes that are being applied to these things by the owners and we have lots of variation and variables to consider eg. batteries, motors, tail booms, winds, density altitude and more! I know Dave has done a bunch of work trying to get a handle on this adjustment pot and I really appreciate all that he has done. Dave is concluding that the pot does not seem to have any effect on tail rotor speed or on how the bird flies and that may be entirely correct. On the other hand, especially in view of the other variables that have to be considered, this is a very difficult determination to make.
I'm guessing the pot is suppose to do something. You don't add a component to the board if it's not going to be used (it's just a waste of money). I'm leaning towards it adjusting "k2", since I didn't see much of a difference in the "offset" on the o-scope when I adjusted it.
Of course, I didn't see much of a difference with either setting. Maybe there's something wiggy with my 4in1. The next one I fix, I'll check that one out as well.
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All Forums >> RC Helicopters >> Electric RC Helis >> RE: Falcon 40 (Exceed heli) Forum 
RE: Falcon 40 (Exceed heli) Forum - 
I ended up clipping her right in the back of the knees! It was moving too. I was swooping down from 20' up with alot of forward cyclic applied. She was wearing jeans so there was no real damage to her other than a nice smart. I haven't talked with her since but I bet she got a pretty good bruise too. If she had stayed put like I told her there would have been no problem. I did feel really bad though. I apoligized a bunch of times but she was still pissed. What are you going to do? I ended up stopping my apoligies and just saying I told you to stay behind me. That didn't help her mood any 
At any rate the heli got the worst of it. Damage: Tail rotor(foolishly I only ordered 1 century tail rotor) flybay again, control ring(my last one) and main blades. I couldn't bring myself to be down all weekend so I glued the broken ball back onto the control ring and sanded the glue off with 400 grit paper. It's holding but not 100% straight so the Falcon is just not flying tip top right now. I should be getting new control rings today or tomorrow. They shipped yesterday morning. I also ordered 2 more of the century tail blades which shipped yesterday night. I should get them shortly too.
