AR7200BX Setup Menu I

[1blahblah]

My first experience with a BX, using a DX8 Tx.

I am confused about Setup Menu point I "Setting the Swashplate Servo Directions".

This is what happens...

Fresh model profile on DX8. AR7200BX factory reset.
Set 1-servo setup on Tx.
Bind Tx with AR7200BX powered from ESC/BEC connected to "THRO".
Plug a servo into "ELEV"
Go to Setup Menu point I.

Now, for all options the servo moves in the same direction with collective pitch input from Tx.

The table in the (Spektrum) instruction manual shows that for two of the options the "ELEV" output should be reversed, and for the other two it should be normal, but none of the options change the behaviour of the servo connected to "ELEV". The AR7200BX behaves as if the table has "AILE" and "ELEV" confused.

Using cyclic input on the Tx, the "ELEV" servo moves on elevator input, and not with aileron input, so it looks as if the BX knows "ELEV" is elevator, so is the manual just wrong??

Please help me understand!

[tracernz]

How it should work:
Move the collective up and down. Adjust the setting until all of the servos move in the same direction. Reverse the pitch channel in your DX8 if they move in the wrong direction. Once you have the swash moving up and down correctly with collective try left and right cyclic, reverse the aileron channel in your DX8 if the swash moves the wrong way. Do the same with the elevator.

The manual isn't wrong in my experience.

[1blahblah]

I have now also read the BeastX manual.

The same table is shown for Setup Menu point I, with different columns labels:

BeastX manual:
CH1 , CH2 , CH3

AR7200BX manual
AILE , ELEV , AUX 1

Now, the BeastX manual shows that CH1 output is for elevator servo, and CH2 output is for the aileron servo.

My AR7200BX is consistent with the BeastX manual, and not the Spektrum manual!

I am looking at the latest available pdf manuals from beastx.com and spektrumrc.com

At this point it looks likely that the Spektrum manual is incorrect, unless it is for a later firmware version than that of my own unit.

Does this make sense? Have I missed something??

[1blahblah]

It would be great if somebody else tests this and reports their results

[jbobb1]

This my set up on my Trex 450 w/ AR7200RX
Menu point I is purple

TX servo direction
Aile - Rev
Ele - Nor
Pit - Nor

Item I in the set menu is for SWASH movement. My guess would be because you don't have all three servos connected, the bx is gettin false signals.

[Excalibur3]

Originally Posted by tracernz

How it should work:
Move the collective up and down. Adjust the setting until all of the servos move in the same direction. Reverse the pitch channel in your DX8 if they move in the wrong direction. Once you have the swash moving up and down correctly with collective try left and right cyclic, reverse the aileron channel in your DX8 if the swash moves the wrong way. Do the same with the elevator.

The manual isn't wrong in my experience.

Trust me I have set up and fly three
AR7200BX's and they all are done by choosing which option makes all three servos move together in the same direction. Then if you have a DX8 and they are moving in the wrong direction then you simply reverse the pitch channel ONLY.


Nano CPX,130X,TREX500DFC,
TREX550EFL, DX8

[sutty]

The elevator could eaisly not change, as it would be irrelevant. If you were the software you would say, start with one, fixed, known, starting point, elevator always goes this way. Now, with each setting, change the other things, until you can get the other two to match the elevator. When they all match, change your Tx settings accordingly for any necessary directional changes. It would be completely arbitrary which one they set to be fixed, but I guess they chose elevator. I have never checked it, I have never needed to. You do as was just mentioned by Excalibur. Hook up all three, move collective, if they do not all move the same way, select one of the options until they do. When they do, reverse the channels as necessary in the Tx to correct the directions.

As for the Spektrum manual being wrong, I don't know, I haven't checked, I only have MBs. If I had a Spektrum the MB manual is much better than the Spektrum one anyway, so I'm sure I would stick to the MB one.

Cheers

Sutty

[1blahblah]

Somebody with an AR7200BX please check. It would only take two minutes to go to Setup Menu I and see which servo is not reversed by any of the options.

Arbitrary or not, the relevance to me is that I will be trusting many hundreds of dollars worth of dangerous equipment to a magic little black box, that appears to function contrary to its manual. I suspect my unit is normal, and works just like all the AR7200BX's that are flying around safely, but it would be comforting to support that view with data, and is nobody even a little bit curious?

[blade450]

Sorry....just took my AR7200BX off or I would have checked.
However, if everything is moving properly on the bench I would not have any problems with that little magic box. Just make sure all directions are correct and you should be okay. And it is possible that they made a mistake in the manual, but I would never find out. I just make sure everything is moving properly and move on.

Sent from my iPad using Tapatalk HD

[sutty]

I wish I could help to give you peace of mind by performing the test on the AR7200BX, but I don't have one. Maybe someone will, unecessary or not.

For what it's worth, it might not be enough for you, not sure, but the MB part of the AR7200BX is most definitely exactly the same as the MB itself, and I have performed the test on one of my MBs, and as you described the elevator never reverses.

Perhaps this point is moot, but like several have now said, it really doesn't matter how you achive it, the only thing that is important is that you have the same direction, and you do not need to have the option to change the direction of all three serovs in order to get that. As you know this part is clearly stated in the text of the manual.

If the elevator goes the wrong way, when compared to your collective stick, then when you get the other two to match it, using one of the four available options, then all three will be going the wrong way. Reverse the pitch channel in your radio and hey presto, all three go the right way. The same applies to elevator and aileron. If they go the wrong way, just reverse them in the Tx.

Yes it is a magic box, but the logic is simple, to get them all going in the same direction, you only ever have to offer options for two of them, as long as you can then overide and change all three together, which you can from the Tx. If there were options for all three, then there would have to be eight options, and you would run out of colours. Sure, if this were available, you would be able to get them going in the right direction too, without the intervention of the servo reversing in the Tx, but this is not necessary, as there is always servo reversing for pitch in the Tx.

I can however confirm that the manual is inaccurate. I have just checked it, and the observed behaviour is clearly in conflict with the table, at least for a MB, which as I stated earlier will be the same. The table clearly states that it will be aileron that doesn't change. I suspect as you mentioned previously that it is simply the column headings that are wrong. The text however does describe the process perfectly, and states clearly that the directions are not relevant, and are corrected later in the Tx.

If you want to be sure you maiden without error, the only way to do this is to make sure that all of your stick inputs give you appropriate swash movement, and when you move the heli the automatic corrections provide opposite corrections to the movement of the heli, and regardless of how long you ponder this step you will still have to do this check at some point, or it could easily go wrong. To be fair it is even recommended that this type of check is performed prior to every flight, so however it is achieved, or whatever happens in step i, if you check it later, it really won't matter what the manual said at that point, because you will be confirming it prior to flight, especially prior to your maiden.

If this doesn't clarify things enough, hopefully someone will be along soon to confirm that the elevator does not reverse, for any of the options available, specifically for the AR7200BX, contrary to the table in the manual.

Cheers

Sutty

[swash-addict]

...

[sutty]

Originally Posted by swash-addict

When it comes to the elevator servo...

Whether it needs to be reversered or not .....depends if the servo is mounted fwd or aft the main shaft......

If you need to reverse it so the swash moves correctly in either of the "options" in the beast/ar7200 step I its no problem.

as long as swash movements are correct for corresponding stick movements there is no issue.... as also said above ....

not sure your question though .......your saying the manual says the elevator should be in normal?

How does the manual know what heli it will be mounted in.... and if it needs to be reversed or not?

The elevator cannot be changed in step i. You can only change the others to match it. Thereafter you reverse all three in the Tx by reversing pitch, if you need to.

In the manual it states that it is the aileron servo that is the one fixed in normal. This is not the case.

Cheers

Sutty

[1blahblah]

Thanks Sutty!

[tracernz]

Just checked on my 450 and can confirm that the elevator servo remains constant for all options in setting I.

[1blahblah]

Reassuring to know, thanks for the help.