Transmitter setup: too much information, don't know what's best

[quintesse]

Hi people,

just got my copter, first time with anything that flies.
Building the thing was easy ([ame]http://www.youtube.com/watch?v=W6boxD9ycCk[/ame]) but I'm having quite of bit of problems flying the damn thing

I've been reading as much as I can (currently have half a dozen helifreak forum pages open + some other sites) but I can't seem to find a straight answer for good transmitter settings for a beginner.

So I already found out that making sure the ESCs are set up properly is vital because otherwise the copter's behaviour is so erratic that it becomes impossible to control (on my first try it suddenly smashed itself full-speed into a nearby wall while I wasn't even manipulating it, except for throttle).

So I read that you should lower the Data Rates to like 50% or so. So I did that which indeed makes it better manageable but I still often and up losing control when the copter starts drifting, I try to correct (carefully!) and it goes faster the other way, etc etc, a vicious circle of corrections until I just decide to land to make it stable again.

But even landing is difficult, the copter seems to have only 2 modes: either shoot up or fall down, with only a minute throttle change between the two (which means of course that whenever things start going wrong I tend to let it plummet to earth).

So I start reading some more.

And the first things I encounter is:

- some people say set your transmitter to ACRO, others say HELI
- some talk about limiting your Data Rate, others talk about End Points (which others say is useless to change) and others talk about "Travel".. what's Travel, is that the same as EPO?
- then people talk about EXPO, which sounds like a good thing to use, but then they say "set it to 40%"... ok, but my transmitter gives me 2 numbers! One "up" and one "down". So what do I put? +40 on up only? +40 on up and down? Or +40 on up and -40 on down?
- and the EXPO doesn't seem to work for the throttle, which is exactly the one I'd like to change (because of the 2 modes I talked about before: shooting up or falling down). So how do I get a more gentle throttle control?

Any help would be greatly appreciated!!

[quintesse]

Ok, at least one thing I can already answer myself. My transmitter is a Futaba and the two values for the Data Rates and Expo is because you can have two sets of values and on the front is a switch that lets you choose between the two (the switch being either "up" or "down").

And on the Futaba a negative EXPO makes for "softer" responses early on, getting stronger the farther you move the stick from it's neutral position in the center. So if people advice a 40% EXPO for beginners because it dampens the typical hysterical reactions "OMG it's going to crash!" (talking from experience here ) on a Futaba that would for example mean that you'd set -40% EXPO on the "down" setting, while leaving the "up" setting for when you want more direct control (or you set them to 2 different values, whatever you feel comfortable with after experimenting).

[quintesse]

AH yes, another thing I figured out (I think) is the difference between the Data Rates (DR) and the EPA (wrote EPO above by mistake):

EPA seems to be the "base" maximum value you will allow a servo to move, or in the case of quadcopters, how fast you'll allow the motors to spin (I guess no much use going higher than 100% in those cases, right?)

Then the Data Rates allows you to to change those values by a certain percentage.
So if you'd have EPA at 80% and DR at 50% you're *actually* setting the maximum servo travel (or motor speed) to 40%.
Also setting EPA to 50% and DR to 100% is exactly the same as doing it the other way around, the result would be the same.

Now in the beginning I was asking myself: why are there two settings doing basically the same?

But then I understood that with the DR you can actually use a switch to choose between two sets of values. Allowing you to use the EPA basically as a "base setting", while using the DRs to adjust them between two styles of flight (at take-off / low speed and when flying at higher speeds for example).

The question I'm still having is that the Futaba manual says that the EXPO depends on the EPA, so does that mean that when using EXPO it doesn't use the DR anymore or what? So if I have my DR at 50% and my EPA at 100% and start using EXPO can I then suddenly push to a 100% again? Bit confused in this one to be honest....

[abcfob]

I built mine a month ago, and had a similar problem. For me the issue was that I read the diagrams wrong, and reversed the wiring on the wrong pair of motors. This was frustrating, because all the motors spin up, and it will sort of lift off so that you think you wired it right, but any amount of right stick input sent it either into a wall, or flipping upside down. This would also manifest itself (in my case) by almost being hover-able when gain is set to 0, but completely uncontrollable if a small amount of gain is dialed in.

I

Ensuring that the correct pair of motors are reverse wired (and subsequently changing props so that they're on the right motors) solved my problem.

[quintesse]

Hi, thanks for your reply.
But I'm pretty sure it's not the same situation, mine doesn't do flips (I did get once when after a crash 2 of the motors flew off and I reassembled them the wrong way around. I immediately painted numbers on them afterward hehe)

I do have a much more controllable copter now, after much fiddling around with the transmitter, gain is 40% I think , but I also turned down the data rates and made the throttle only go to 60%.

Still I could never fly this thing inside the house, it's way too twitchy and it seems to overreact whenever it touches something (the ground for example, a bump into the ground will suddenly turn into this wild boost skywards).

I also find it difficult to maintain altitude, I'll get it to hover (not in one place it will go sliding off in a random direction and I 'll need to correct it continuously) but when I decide I want to go up a bit I find it difficult to find a stable point again, it either keeps on climbing or it hurtles back down.

I still need lots of practice. At least it was fun for my friends seeing the video of all the crashes

[abcfob]

Ahh, i see Practice helps, I have a smaller quad (Blade MQX) I practice on. its nice because I'm not afraid to crash that one, so its easier to learn tricks.

If its touching the ground and then hurtling skywards, the only thing I can think of that would cause that is a high gain setting. How does it handle this situation if you turned the gain off/low?

There's possibility of some ground effect, but if that was the case you'd see it only climb a little until it is a few feet off the ground, and then it wouldn't continue further.

[quintesse]

I have the Gain (GYRO on my Futaba with HELI settings) set to +35%, is that too much?
What does the Gain setting DO? That was never really clear to me...