Dx8 and helicommand set up question. Help.

[noste500]

I am setting up a hc3sx with a dx8.
The part where I set the head gain is confusing me.
It's says to set head gain @50% in both directions.
I have my head gain channel set up on the knob / dial on my tx and can see it going to 100%
In both directions when I twist it fully both ways.
How can I " set it to 50 % in both directions "?
If I twist it to 50 one way then write it, then go 50 the other way and write it , it will just write over the first selection.
Do I just set it to 50 one way and save ? And add more less gain on the knob to adjust when doing my set up flights with the unit??


Also I have just set tail gain to + 50 on my flight mode switch (All 3 f modes ) Therefore it will
Be in heading hold all the time, is this ok??? I don't normally fly in rate mode.


Thanks in advance guys.

[Stanley Speel]

Re: Dx8 and helicommand set up question. Help.

Hello

For the head gain dont use the tx to adjust it use the slider in the software.

Start at about 50% and increase 5% at a time until you see vibrations then decrease by 5%.

With tail gain anything above zero in the software will be heading hold iirc. On the diagnose page it will tell you if im hh or rate mode. You always want to be in heading hold.

[450man]

For the set up flights I would set up the head and tail gains on the R TRIM and L TRIM momentary switches rather than the knob. That is what I did. It means then that you can adjust both the gains easily at the field without having to have a laptop with you.

Obviously you won't be changing gain settings in flight (aaagh!) but you can test fly, determine if the gain must go up or down, land, change the gain a few clicks one way or the other and then immediately fly again. In a single flight I had my head and tail gains all properly set. Once you have done that you can return home, connect it up to the software and insert the values you found worked for you into the software as the default values for tail gain and head gain. Once you have done that it then frees up those two channels for using Horizon mode and real-time tuning.

The "both directions" this is a red herring. It doesn't make sense. Just make sure as Stanley says, that all your values are positive so you stay in HH. Double check on the diagnose page that the switches work in the direction you expect and that you have the tx set up correctly so the R TRIM and L TRIM adjusts the head and tail gain as expected. The biggest friend I find when doing anything with the HC3-SX is the diagnose page... that will confirm precisely what the controller is actually doing when you use the tx.

Edit: Forgot to say... I would start at +50% on each. My settings came out to something like +78% and +48% (can't remember which way round they were though) so +50 is a good starting point and that will put you smack bang in the middle of the HH range (HH being positive 0 - 100)

[RcRotaryMadness]

I had a helicommand once, I seem to remember all the settings and adjustments being made in the heli commands software not the TX?

[450man]

I had a helicommand once, I seem to remember all the settings and adjustments being made in the heli commands software not the TX?

Yes, that is how you do it but when you are adjusting the gains it makes sense to set up the TX to makes those adjustments in the helicommand. You are right... all adjustments regarding servo travel, centrering, swash leveling, trim etc must be done in the software and not on the tx. But this is different. You are using the tx to adjust the software values via the AUX2 and AUX3 channels. That is quite different because you are actually adjusting it in the software but via the tx.

Once you have found the correct settings for your heli you can then transfer those values to the "default" values in the software and that then frees up those two channels.

[noste500]

Cheers guys , I'm on it..

[NoFixedAbode]

Re: Dx8 and helicommand set up question. Help.

I have just set one up on my 550 and at one point it tells you to set the servo at 90° and use the sub trim. That's is before you get to the <> to set your swash level. So to trim my drift out I guess it ok to use sub trim. Even though software ays not to alter tx after set up.

[450man]

I think I know what you are getting at...

Before you start with the servo set up you go into the DIAGNOSE tab. In there you are setting up your TX. That is where you can adjust your TX to get full movement using the travel/subtrim on the tx. You also change direction of travel to make sure they move in the correct direction. You adjust the tx to get full movement of the bars using travel to get full range and the subtrim to get center. This is the only reason you would set anything on the TX.

Now you leave the TX alone from then on. Everything else is done in the software.

The idea is that you adjust the TX in the DIAGNOSE tab only to get the correct response from the bars... not the heli! You Then adjust everything else in the software to get the heli to respond correctly to the software. Remember... when you move the stick on your TX you are NOT controlling the servos. You are giving a control command to the HC3-SX and it then works out what it needs to do to get the heli to respond correctly. So the ONLY thing you should adjust in the TX is range and centering of each channel in the DIAGNOSE tab. Once that is done the HC3-SX knows how to interpret your commands. So changing something on the TX after you have set it up in the DIAGNOSE tab will confuse the HC3-SX as you will then be telling it one thing and it will be interpreting it as something else.

Just to be clear, I quote from the manual...

4. [Diagnose ] menu : setting up the transmitter
Check that each bar in the [Diagnose] menu is assigned to its correct function and only this function, i.e. without
any mixers! Then program the RC transmitter for:
a) Correct signal direction of each bar, by means of the transmitter‘s servo direction
b) Travel of all channels all the way to their end-markings as displayed at the [Diagnose] menu (e.g. with robbe/Futaba equals
120 % in the transmitter)
c) Adjust the transmitter‘s trim, so the bars for aileron, elevator and tail are exactly neutral. Pay attention to the „< > „ signs shown
above the bars.
If all this is set properly, do not change anything in the transmitter from now on, except for the auxiliary channels Head- and
Tail-gyro, and - in case of the HC3-Xbase - the stick travels during later setting of the desired agility.

Servo centering can be done in the TRIM menu. The TRIM menu always sets all servos to centre whenever you enter that menu. Then you mechanically set the horn as close as you can to centre. You may need to remove the servos to do that or, do as I did and centre the horn before you install the servos into the frame using a servo tester. You can never get the horns exactly centered but don't worry about that is accurately set in the software. Just get it as close as you can.

Now the servos are mechanically centered as close as you can get them so we now use the +/- buttons in the software to precisely center the horns.

Now the software knows the servos are accurately centred so still in TRIM tab you can mechanically level the swash.

So when you have done that, the software knows the servos are centred and the swash is level. Job done.

You can then go on the the MIXER tab where you set the direction of travel for each servo so the swash moves in the right way. Note, this is not done on the tx. Also in the MIXER tab you set the cyclic servo limits. Again this must be done in the software and not the TX.

Then into the TAIL menu where you set the tail servo limits... again in the software.

Things must be done in this sequence.

What is important here is that the only thing you adjust in the TX is the travel/subtrim to get full movement in the DIAGNOSE tab. Everything else is done in the software.

So, in answer to your question about using subtrim to fix a drift... the answer is a firm (but friendly!!!) no! Doing that will fix the drift when you are controlling the heli but as nothing has changed in the software the drift will still be there when the HC3-SX takes control in bailout or self-level mode. The software won't know that you have adjusted subtrim on the tx so to the software nothing has changed and the drift will remain.

If you have a drift, what I would do is:

1) In DIAGNOSE check you have full movement on all controls and that they are centered. If not then readjust on TX. If you had to change something here then I would re-fly and see if the drift has gone.
2) If the drift remains, go to TRIM, check that servos are centered and the swash is level. Use the software only to adjust. Remember... use +/- buttons in software to center servos then mechanically level the swash. Re-fly.

Everything is now set up correctly in the software with the servos centered and the swash level so if drift remains then it is probably a mechanical issue with the heli. You could perhaps then adjust the swash links slightly to mechanically trim out the drift but I would then be asking why the drift is there at all with the software properly set up and the swash level. It might need more investigation mechanically.

[noste500]

I got mine set up last night fellas , setup flight later today .

[NoFixedAbode]

Re: Dx8 and helicommand set up question. Help.

Ooh that's a lot to take in. What I can't decide if you set trim to eliminate drift in diagnostic tab then mechanically the swash is no longer level with the tool.

Atm on the 450 I have dialed out drift with sub trim and all works a treat.

[450man]

NOOO! You don't set trim to eliminate drift in DIANOSE tab... that is my very point...

The only thing you do as far as the transmitter is concerned is in the DIAGNOSE tab adjust the tx travel, subtrim and direction so that you get full range on the bars in the correct sense and they are centered. It is the bars in the DIAGNOSE tab that matters as far as the tx is concerned and nothing else. You do not adjust anything in the DIAGNOSE tab to change anything on the heli. If the DIAGNOSE tab is set up right then your tx is set up right. End of story.

If you get full range (line to line) on each control in DIAGNOSE tab, that is up to the line on each bar, and you use the < & > to get everything centred, then that is you done and dusted with the TX.

If you then still have a drift do not adjust anything on the tx. You must recenter the servos and relevel the swash and if you still have drift then there is possibly a mechanical issue and then your only option is then to adjust the appropriate swash servo to correct it but if you have to do that then in all liklihood either the swash isn't level and/or the servos are not centered... but whatever you do don't touch the tx.

I know it is tempting to just add a bit of trim. Why should you go through all that hassle to hook up to a computer just to fix a bit of drift? Well you simply must or you will have problems with self-leveling and bailout. Sorry

[450man]

Atm on the 450 I have dialed out drift with sub trim and all works a treat.

In that case I bet you have drift in self-level mode and bailout.

If you say you don't then I suspect you hadn't got it set up right in the DIAGNOSE tab and/or that the servos are not centered and/or that the swash isn't level... or I suppose you could have a faulty HC3-SX but I am assuming, rightly or wrongly, that our units are working properly.

It is simply a fact that the way it works is that the HC3-SX must know what you are asking it to do and it does that in the DIAGNOSE tab by making sure that what it thinks the tx is doing is what it is actually doing... that centers, direction and range of your TX signals match what it is expecting. If you change something on the TX after properly and correctly setting it up on the DIAGNOSE tab then your tx will not match what the HC3-SX thinks your tx is doing.

[sooren]

I had a backward drift with my Logo 500 and all I did was go to the trim tab and put one click up on the rear servo and one click down on each of the front servos - drift was gone - it should be noted that no more than a couple of clicks with this method, got the idea from Helifreak, worked for me.
Regards
Paul

[NoFixedAbode]

Re: Dx8 and helicommand set up question. Help.

Yea 450 I am lazy. Sub trim for drift was like 2r and 4u.

[450man]

@sooren - yes, that would be fine as you are not changing the tx. That is what you would have changed anyway to level the swash so perhaps your swash wasn't exactly level and your changes in the TRIM tab might have leveled it.

@nofixedabode - yep, I think most of us are lazy! However, if you are happy with it then who am I to disagree but if you get drifting in self-leveling or bailout in future then I would go back to do the DIAGNOSE again and TRIM after.