450 AR7200bx setup

[Demon]

Hi,

I'm doing a flybarless conversion on a blade 450 3d. I got an ar7200bx to do it with. I have see the many videos with setting up the unit, but it's not really clear to me how to 90deg the servos and level the swash and then get 0 deg pitch at mid stick. Is all this done via the beastx setup? Previously i was using subtrim to 90 the servos and turned the links to level the swash and also turned the links to get 0 pitch on the blades. But I see no one mentioning any of that with the beastx setup.

Thanks

 

[Tony]

On page 13 of the manual, Step G, it explains how to set the servo centering up. One thing to remember is you must use a 1 servo 90º setup in your Tx. All adjustments are done through the gyro, not the Tx. It does take a bit longer from what I have seen, but it's worth it with as stable as this gyro is.

http://www.horizonhobby.com/pdf/SPMAR7200BX-Manual_EN.pdf

 

[Demon]

I have reviewed step G previously. So just to be clear - I put on the servo horns as close to 90 as possible, then I use step G to center them exactly to 90. Then I mechanically adjust the linkage to the swash to center it, then i put on the head and mechanically adjust the blade links to get 0 pitch?

What if I have a DFC head and the blade links are not adjustable? This is the head I have - http://clubheli.com/images/products/8760.jpg

I'm guessing that in this case, once I have the swash level, in order to get the blade to 0 pitch, I would adjust all 3 links on the swash equally to raise or lower it to get 0 pitch?

 

[Tony]

That is correct. attach the arms to the servos to as close to 90º as you can get them. Once there, you will use step G to set them to a perfect 90º to the links. If you do not have 0º pitch at mid stick and 50% pitch curve, then you will adjust the servo to swash linkages to achieve this setting. After leveling the swashplate, be it by tool or zip tie, if you have a different setting for full positive and negative pitch, then you dont' have your servo arms at a perfect 90º. If you have more positive than negative, then your swash is too high, and you need to go back into menu G and lower the servo arms. If you have more negative than positive, then you need to raise the arms. By doing this, you can get a perfect setup on your head every time. Hope this helps.

 

[Demon]

So you're saying that after 90'ing the servo arms and leveling the swash, if i dont have the same neg and pos pitch, i should NOT fix that by adjusting the servo to swash links? I should fix that by going back to step G and adjusting the servo arms so that pitch is the same on pos and neg (but the arms will no longer be at 90). Is that correct?

 

[Tony]

The arms will be at 90º. However, if you are getting different readings, then the arms were not at 90º to the links. Everything about the head of these helicopters has to do with geometry. If everything is not perfectly the same, then you will have differences in pitch. As long as you are not binding at full positive and negative pitch with full cyclic as well, then your swash is leveled and you can just adjust G. These will be very slight adjustments to step G.

If this doesn't make any sense, I will see if I can find time to make a quick video on what I"m talking about this weekend. It's a slim chance that I can do it, but I'm going to try.

 

[Demon]

Thanks. The head is coming today, so I should be able to try it today or tomorrow. I'm pretty sure I'll get it once I get into it. I'll report back. Thanks for your help.

 

[Tony]

My pleasure. Let me know if I can help further.

 

[mainly]

On page 13 of the manual, Step G, it explains how to set the servo centering up. One thing to remember is you must use a 1 servo 90º setup in your Tx.

im at this step now but on my transmitter , the dx9 there is no "1 servo 90 mixing" option in the swash type menu.

what should i do? or am i not at the right menu?

 

[Tony]

You will use the Normal setting on the DX9.

 

[Lee]

If the servo arms are at 90º, and you have a linear pitch curve, at mid stick, you should have equal Pos and Neg.
If the swash is giving you more pos than neg, or vice versa, then its the arms that need adjusting.
This will raise or lower the swash. Then you will have to readjust the Swash to Blade grip links to return the blades to 0º pitch.

Example.
With servos all 90º.
0º pitch at midstick.
You have 13º+ and 11º-
Screwing your servo to swash links in by one turn will give you 12º+ and 10º- and 1º- at mid stick.
Then go to your swash to blade links and extend by one turn. This will return your blades to 0º at mid stick and give you 11º+ and 11º-

Hope this helps.