Setup ar7200bx - negative pitch in menu K

[Torben]

Hi
After a crash I am in the setup process with the ar7200bx on a trex 500.

I have a problem In menu K. I can adjust it to 11.0 degrees positive pitch but only to max -8,4 degrees negative.

Can some of you tell me what is wrong?

Is the servos gone or...?

Thanks in advance

Torben

[bad007]

Usually that means your servo horns , 0deg. mid stick are too high.
Not level, give the rods at the horns 2 turn out and then the rods to the mains about the same in and redo. Servo travel at the horns is not linear, small changes = big changes at the end of it's travel. Grab the horns and check for slop when setting them level.

[Indokast]

May have to recenter servo arms on the servo or adjust linkages to swash. Only things off top of my head I can think of. Or make sure you have full servo range set in tx.

[Torben]

Hi

Thanks for your replies.

I can't get it right. I have tried to adjust as you suggest.
I sat the linkages as showed in the manual: The lower linkages (on the horns) are 18 mm and the upper linkages (on the blades) are 36 mm. Do you start in another way?

[bad007]

Originally Posted by Torben

Hi

Thanks for your replies.

I can't get it right. I have tried to adjust as you suggest.
I sat the linkages as showed in the manual: The lower linkages (on the horns) are 18 mm and the upper linkages (on the blades) are 36 mm. Do you start in another way?

That's a starting point, not a final setup. Refer to first post again

[bad007]

Originally Posted by bad007

That's a starting point, not a final setup. Refer to first post again

You sure you have step G right? All servo horns level and 0deg. pitch on the blades?
Crash? always grab the horns and run the servos, stripped or damaged gears will show up applying resistance. I use the plastic gears and replace all of them after a crash.

[Torben]

Okay, my mistake. I forgot to set pitch curve to 0-25-50-75-100 .

That helped - a little.

But I can't figure out the geometry. Now the horns goes all the way down and hitting the frame. At mid stick there is 13 mm from the frame to the bottom of the swashplate. Is that correct?

In menu K the horns immediately goes all the way down and make the buzz sound...

[bad007]

You need to go to G status led off without the horns on for reference starting point and install the horns at close to level position as poss.
Even shuffle them around so they are as close to level as poss. Then proceed to level them, grab the tip of the horn and wiggle them while finding there level point. After level set 0 deg. on the mains. Get the swash height so you don't hit the frame with full neg Pitch + Aleron

[Torben]

Hi
Thanks for your reply.
I'm not sure if I understand what you mean with this:

"grab the tip of the horn and wiggle them while finding there level point"

Normally I enter G without the horns on. Then I set the horns as close to 90 as possible and then level with the swash level tool. Thereafter I set the blades to 0 degrees. I try not to move the horns after I have installed the horns.

[crashcopterman]

Torben

If I may, some of the advice you are getting is not necessarily very good, quite vague at best. I think your best bet would be to relearn the setup via the stickies, I will post a link below. Focus on G, J and K, but G is definitely the step that newcomers tend to struggle with. These individual YouTube clips on the setup are done very well, I think you will find them extremely useful.

Cheers

Steve

https://www.helifreak.com/showthread.php?t=305195

[Torben]

Hi Steve

Thanks for the links.
I have seen many of the videos before and I have previously succeded in setting up the ar7200bx menu G. But then the lower linkages had the perfect length. Now after my crash I have made new linkages and set their lenghts after the manual. But it seems to be a problem because they hit the botton. According to the manual the lower linkages schould be 18 mm long. But is it normal that I have to turn them in to about 16-17 mm?

It is a trex 500 pro efl

Sorry for my stupid questions

[bad007]

Originally Posted by Torben

Hi Steve

Thanks for the links.
I have seen many of the videos before and I have previously succeded in setting up the ar7200bx menu G. But then the lower linkages had the perfect length. Now after my crash I have made new linkages and set their lenghts after the manual. But it seems to be a problem because they hit the botton. According to the manual the lower linkages schould be 18 mm long. But is it normal that I have to turn them in to about 16-17 mm?

It is a trex 500 pro efl

Sorry for my stupid questions

You mean you shortened them to get your 0deg on the mains? Better of adjusting at the grips to keep the swash higher to prevent contact with the frame. Maybe some pics?
""Grab the horns and check for slop when setting them level."" Both my 500s with align servos have a tiny bit of slop and a wiggle on the horns helps find center better. Perfectionist I am. Also BTW if you started with 3.8 and upgraded there is a couple of changes for 4.*

[crashcopterman]

Originally Posted by Torben

Hi Steve

Thanks for the links.
I have seen many of the videos before and I have previously succeded in setting up the ar7200bx menu G. But then the lower linkages had the perfect length. Now after my crash I have made new linkages and set their lenghts after the manual. But it seems to be a problem because they hit the botton. According to the manual the lower linkages schould be 18 mm long. But is it normal that I have to turn them in to about 16-17 mm?

It is a trex 500 pro efl

Sorry for my stupid questions

Ok, I think the biggest issue is that most people take the manual as the gospel, use those measurements only as a guideline. Your head hardware and swash height/"straight" swash driver arms dictate link length. There are fundamentals that need to be followed then final link lengths will be determined thereafter.

I hope this helps, if not I can link a YouTube clip I made for another member on a different machine, but they all work the same way.

Cheers

Steve