General A few misc lingering helicopter questions for newbie

[mooserider]

Hi, there are a few questions that I have had a hard time finding an answer for that I'd like to learn before I try a test flight. Hope someone can point me to another thread or help answer some of these.

1. On the 3gx, the main status light when the 3gx is initialized... I think this "head holding" (green) and "normal" (red). Is "normal" the same thing as "rate" mode (I see the term used a lot). This status light also corresponds directly to the rudder delay setting I think?

2. If you set the rudder delay to "normal" (red), then does the value for the delay even matter what you set it to? That value I'm guessing applies only to head holding?

3. I have only one flight mode set in my Tx (DX7). The 'norm' mode. I really haven't changed anything in the default settings for a heli, other than subtrim for 90'ing the servos. I assume this is ok for simple flight. I have throttle hold (cut the motor), but that's it. There is nothing set to keep the rotor head at a set speed ("Idle up"?).

Thanks for any help!

 

[Tony]

1. yes, a green light is what you should ALWAYS fly with and is Heading Hold mode. A red status light is RATE mode, meaning it will not move the tail back to where it started, but instead, it will only stop the movement of the tail. Rate should only be used for setting up and verifying you have the correct settings.

2. You should always set the delay as low as you can possibly get it. The ONLY time you should use delay is if you have a slow tail servo. It can help get a slow wag out of the tail.


3. If you are just getting into flying helicopters, then normal mode (where you drop the stick and the motor stops) is right where you want to be. Get familiar with the helicopter and then try using some idle up.

Hope this helps.

 

[mooserider]

Thanks Tony! The delay on my heli is 10. I hooked it up to the computer and that's the lowest value. Hope that sounds right.

One other question I forgot to ask is about the two physical gain 'screws' on 3gx and if/when you adjust them. Mine are straight up and down, factory set... 50% it looks like. Is that an OK setting for now?

 

[Tony]

That is a pretty good place to start. Most people will hook this up to their computer and set those dials to 105 and usually never have to move them again. This is what I do and I suggest you do the same. But you can see how it flies as is if you like.

 

[mooserider]

Well... I went out to do a test hover on Saturday and something is off. Maybe more than one thing. I've very glad I had the test flight 'sticks' on the bottom. First I should say that it was a windy day. I waited in between wind gusts, and I'm not sure how stable the thing should be in low winds or how it should react. It's the only time I had to test it out this weekend. So here are the things that I don't understand.

1. First off, it's way, way, way, waaaay too touchy. I have all the settings set to what you suggested for a beginner. I forget them all exactly, but it was something like 20%, 20%, 70%, 70%, 0%. For the collectives and such... the last thing the video has you set. I can't say for sure about the ailerons and elevator, as I didn't have much chance to use them. But the tail rotor... holy cow! You barely touch it and it whips around 90 degrees (both directions). The throttle also, there's about one click between sitting on the ground and it wanting to keep going up and up.

2. When I come off the ground (as slowly as possible), the thing turns to the left almost 90 degrees right away.

3. If I didn't know any better, I'd say there's no kind of 'stabilization' in play here. It would not keep itself level after coming off the ground well... it would tilt (sorry for the lack of terms here) left, right, forward, back (ail & ele) immediately. Between this and the rudder twisting the heli, it was difficult to keep level for more than 2 or 3 seconds.

I also have a question about the status light again, as what we discussed earlier is not what I'm seeing. My status light is always red. I switched the setting for the rudder (the 5th light on rudder settings, for 450 or less, or 500 and higher). Switching that does not affect the status light on the 3gx (when it's out of rudder settings and initialized normally). I tried it several times... those two things don't seem to be directly related. So I'm not sure how to get my status light green.

I have some of it recorded on my phone, and I'll try to get something uploaded. In the end, I brought it down a little hard on the tail once and stripped the tail drive gear (the one that meshes with the main gear). The replacement is on its way. I can't wait to get some settings fixed and give it another shot. All in all, that thing wanted to jump off the ground and get moving badly!

 

[Tony]

The status light os red because you are in rate mode on the tail. Go into the gyro menu on the tx and make sure you are at 65% and tjat your switch is there as well. If you can, get some screen shots of the flight mode settings from tje 3gx software.

 

[mooserider]

I will see if I can get a clean way of showing my settings or exporting them from the 3gx application. Screen shots won't help, as the display is very buggy on Windows 7. This is version 2.1 I think. So I rely heavily on the 3gx light settings.

For the Transceiver, here's what I have for the "Gyro Sens" menu from the DX7:

Auto Selected (this can be changed from "Auto" to "Rudd D/R".

The "Auto" menu looks like this (two columns):

Rate: F.Mode
0: 50% Norm: 0
1: 50% Stnt: 0
Hold: 0

The "Rudd D/R" menu has only the 'Rate' column.

The F.mode values can all only be set to 0 or 1.

- - - Updated - - -

Oh, by the way. I'm curious about some of the switches. Since there are only two positions (0 | 1) in the gyro sensing F.mode settings, I wonder if my switches are correct on the Tx. This is the 'airplane' version of the DX7, so they're labelled different. The best way I know of at seeing what the switches control currently is by seeing what 'moves' in the Tx's channel menu (I guess that's what it's called... it lists all 7 channels and their stick positions).

Here's what I see...

Switch:
Mix Rudder D/R (2-positions): Changes the Throttle channel (this is also currently working as my throttle hold).
Flap Mix: (3-position): This barely, barely moves the rudder channel marker. It also disables the trim switch for the Aux2 channel.
Aux 2: (2-position & a trim switch): The switch does nothing. The trim moves the throttle channel marker.
Gear: (2-position): Does nothing.

I'm guessing eventually I will want to use the Flap mix switch for my flight modes (normal, idle up, whatever else). But for now, I just don't understand enough how the very basic settings should be hooked up to switches. It doesn't seem like the gyro is trying to stabilize anything. I'll go back and read the DX7 manual again for the 20th time. It isn't very good... the helicopter sections is short and confusing. And this stuff being labelled for planes is just over complicating things for a newbie. Arg!

 

[mooserider]

***UPDATE***

Well, I think I discovered something that was wrong (from my previous setup with the extra receiver wires). In the Tx, "Input Select" was previously Aux2:Gyro, Gear:Inh. I changed this now to Aux2:F.Mod and Gear:Gyro. After doing this two major changes happened. The Flap Mix (3-position switch) controls the 3gx status light now... I can actually set it to green finally. The rudder servo also responds to tail movement now.

Something is off still, but I'm guessing it's irrelevant at this point and I need to go through the full 3gx setup again now. So I'll do that and report back.

 

[mooserider]

Well, I went through the 3gx setup again. Double checked my settings on the collective also (20% ail/elv, 0% ele gain, 0% ail gain, 70% on both dampening, 0% swash acceleration).

The most notable difference now is that (when the 3gx is initialized normally) the rudder wants to move easily while just handling/moving the heli (with the status light green). About as easily as it does when setting the rudder compensation direction in the rudder setup. Is this normal? Maybe it's because it's not in real flight/spool up?

Also, putting throttle hold on cause the rudder to go full left stick. Why would it do that?

One last thing... the Flap Mix now toggles the HH and rate settings in position 0 and 1 (status light green/red). The rudder behaves correspondingly. However, in the Tx, this clearly controls "Norm", "ST-1", "ST-2", as they flash depending on the switch's position. Is it normal to have both the HH/rate setting and the throttle/pitch curves using the same switch? Or does this show I have something set up incorrectly?

Thanks again for the help!

 

[Tony]

I think I'm lost here lol and I apologize for the long wait on the reply . You say you have the dx7. Is this the original dx7 or the dx7s? For the dx7s, you can watch my DX8 videos and it will help out with the program. Bit if this is an old dx7, then I'm afraid I don't k ow much about setting that one up. Let me know.

 

[mooserider]

Hi Tony, no sweat, I have to wait for a part on Friday anyhow. I just appreciate whatever help you can give.

This is for the older DX7, not DX7s. Long story short, I think I made some progress by remapping the aux and gear inputs. Really I have two main questions at this point...

- When you move your 450 around in you hands (not spun up) with HH (green status) enabled, does the rudder servo respond in real-time? This is w/o spinning it up. The gyro reacts so much, I'm just not sure if that's normal. It moves as freely as it does when you're setting the rudder compensation direction in the rudder setup menu.

- Is it normal for your HH/Rate switch to also control the throttle and pitch curves. I.e., mine toggles both the HH/rate setting on the 3gx, and the 'normal' and 'st-1' throttle/pitch curves in the Tx. Not sure if this is expected.

Hope that helps. Thanks again!

 

[murankar]

In head hold mode the tail is going to pitch until the gyro finds the starting of the drift. It will stay pitched if the nose does not drift back. Recenter just flick over to rate mode then flick back to head hold.

Sent from my LG-E980 using Forum Runner

 

[mooserider]

Ok, thanks Murankar. I believe I understand the idea... in that the heli is not responding to it's tail gyro correction, so it's a sort of feedback loop that's happening (as it doesn't 'feel' the response, so it tries to correct even more. I think it's just that this wasn't set up right before, so it wasn't happening and kinda stood out.

Anyhow, thanks! I really appreciate the info!

 

[Tony]

It sounds like you have some mix in there somewhere. Go into your mix menu and delete any mix that yo uhave. There should be no mixing on the Tx at all.

 

[mooserider]

Well you guys, I think I finally figured it out. I found a user on youtube that I was able to talk back and forth with that had a DX7 (non-S). In short, that input select was wrong. The setting should be Aux2:Aux2, and Gear:Gyro. That fixed it so my switches all work properly... normal/idle up1/idle up2 is on the flap mix switch, and HH/rate is on Aux2.

I did a test flight last night in a parking log with some light, and it's much better! It's still too touchy... well mainly the rudder, it just moves too fast for me. It might also need some rudder adjustments, but it's 10x more stable than last weekend. I'm waiting for the wind to die down so I can go play with it a little more!

Tony/Murankar, thanks so much for your help! I was thinking of making a new thread with the settings on the TX in case it would help someone else in the future. But it might just be obvious stuff since I'm a newbie. I still don't understand why Aux2 is set to itself... but hey, it works!

Btw, how can I make the rudder stick less sensitive? I can't think of any settings on the 3gx that does it, either in the rudder or cyclic settings. Is there where I should use the Tx? Reduce the throw on the rudder servo?

Thanks again all!

 

[Tony]

Aux2 is set to it's self meaning that the Aux2 switch is mapped to the Aux2 channel on the Rx. Hope that makes sense.

to make the rudder less sensetive, go into your Dr/Expo menu and lower the dual rate about 15-20%. So if you are on 100%, lower it to 80 and give it a try. This should help tame it down a bit.

As for making a thread explaining the settings, please do so. It will help others in the future that have the DX7.

I'm glad you got it going though. Sorry I couldn't be more help. Never have had a chance to play with one.