Swash Mis-Action?

[Firebrand]

Gents--

Just completed my TRex 500ESP build controlled with my DX8 TX/RX set. Levelled rotor head and programmed ESC and looking good.

Powered up to test all electronics and noticed that the swash moves differently than other helis I own, like a 120SR when I apply left and right aileron on the right stick. Instead of tilting the plate up or down on the right, the whole front of the plate moves up and down; that's both servos acting together. Seems odd compared to how the 120SR swash moves for the same stick functions.

These are stock Align servos and the DX8 settings are from this Forum.

Suggestions, please!

[Larry227]

Perfectly normal for a collective pitch heli. One servo moves up while the other side moves down.

You might benefit from watching the CCPM setup videos here http://www.helifreak.com/showthread.php?t=41692

[Firebrand]

Larry--That's not what's happening. BOTH servos push up and/or down together like they are tied together. This is normal?

[Ozz58]

Larry--That's not what's happening. BOTH servos push up and/or down together like they are tied together. This is normal?

No!

Did you set the radio up? Did you pick the correct swash plate in the set-up?

Do your servos all move the same way when you move the collective stick up?

Answer these two questions will help us help you,

Craig

Also watch the video Larry linked to. There are two videos, a little long and really won't answer you question until the end, but watch the whole (both) video.

[Larry227]

Yeah sorry, I misunderstood.
First off make sure your model setup in the radio is for 3 servos/120*. Then move the collective up and down. Do they all move together? If not reverse the one servo that's moving the the opposite way.
Then see if they're moving the proper direction. Full positive collective should move the swash up. If it's moving down instead just invert the "Pitch" setting in the swash mix. ie; if it's +60 change it to -60 or vice versa.

Then check aileron. Stick to the left should tilt swash to the left. If it's wrong reverse the Aileron mix setting.

Then check Elevator. Stick forward should tilt the front of the swash down. If it's opposite invert the Elev mix.

Once you have everything moving in the right direction you can move forward with your setup.

[Firebrand]

Yes, I set up the DX8 following instructions in their manual and following threads on this site covering settings for the DX8 and the TRex 500.

Yes, I chose the 120* Swash.

I will watch the videos in their entirety and then triple check my servo wiring and then report back tomorrow with results. Will check to see what effect collective has on swash as well along with stick positions for both.

Thanks!

[Firebrand]

Gents--I just went through the radio setup and found I needed to reverse the aileron servo direction and now the swash is moving correctly when commanded!

Also, checked my head leveling with low, mid and full stick on the collective and it looks correct.

I'll attempt a full-up test outside later when temps climb out of the basement here in NH. We hit -7*F this morning and like the servos, I'm not ready to perform in those conditions just yet. Thanks for the insight and getting me on the right track. Sometimes the little things pile up and it's hard to see the trees for the forest.

[Larry227]

Glad you got it figured out.

[Mateyhv]

Gents--I just went through the radio setup and found I needed to reverse the aileron servo direction and now the swash is moving correctly when commanded!

Also, checked my head leveling with low, mid and full stick on the collective and it looks correct.

A bit late here but of course the swash plate movement must be logical to the stick imput. In my case I had to invert channel 3 (aileron) and 6 (pitch) to achieve a normal swash plate movement.