Synergy E5 with E7SE metal tail slider -- unequeal throws

[curmudgeon]

I posted this on HeliFreak, but this dedicated Synergy forum should be a better source.  My Synergy E5 has 121 flights under its belt without issues.  Today, I decided to bling it up a bit.  I removed the stock plastic tail slider, and installed the E7SE metal tail slider.  I set it up as per the manual with the tail bell crank at 90° when neutral.  The issue is that the tail slider itself is not at mid shaft when neutral, so I get more rudder left stick throw than right stick throw.  I included this video:

https://www.youtube.com/watch?v=SHWl0NQ2RQI

Any recommendations?

[James F]

As I posted on helifreak it has pitch built in.  With my skookum I do the setup and set my piro rates and good to go.  The extra travel one way is to counter the torque from the main blades.  Without it your heli would piro slower against the torque than with it.

[curmudgeon]

I believe we may be confusing the issue.  I adjusted the tail push rod length so that at neutral (tail servo arm at 90° to the tail pushrod) the bell crank is at 90° to the boom.  As you mentioned, this yields a built-in pitch (about 5°) against the main rotor torque.  I maxed out the right rudder command (against the main rotor torque, CW) to the mechanical extreme.  However, an equal VBar tail throw (96/96) for the left rudder command (with the main torque, CCW) leaves about 5mm of tail shaft untraveled.

I read a thread some time ago on either the BeastX or the VBar forum discussing tail blade pitch and blade stall.  The numbers I remember are approximately 30° tail blade pitch against main rotor torque (CW, right rudder command) and 15° pitch with the main rotor torque (CCW, left rudder command), and to not worry about not using all the tail shaft travel.  I believe VBar/VStabi even mentions that too much tail travel (tail blade pitch) can reduce tail authority.

I understand that Synergy recommends using all the mechanical tail travel on the torque tube helicopters, but the information from the different forums is conflicting.

[curmudgeon]

I measured the tail pitch with my current setup.  9.7° against main rotor torque at neutral, 35.9° mechanically maxed out right rudder command, and -13.7° with equal travel right rudder command (with the main rotor torque), but still have another 5mm of tail shaft not traveled.  How do these numbers look?

[James F]

I have never measured mine as with skookum you set main pitch to zero and adjust tail for zero pitch and then set left and right limits.  The sk unit then control piro speed in deg per second.  I want to try checking off blur piro's on tail tab two just to try it lol. 

On my E5 I have something like 90 one way and 100 the other for travels.  I would have to hook it up to my laptop when I get home to know the exact numbers though.  There is a 10-15 difference in travels.

[Mike Spano]

i did not have this issue with either of mine. mine were very close to the same number and centered on the output shaft. are you sure everything in the tail is assembled properly? i know your a very experienced builder, i am sure it is correct, but it is worth checking.

my vbar numbers were around 10 off from each other i believe....

i have never physically measured the pitch though, so i cant comment on that.....

[James F]

For me my tail is assembled as per the instructions.  I can set end points the same but it would leave extra travel on one side like the op.  For centered slider on shaft the bell crank would be off 90deg.  My actual numbers could be closer as it has been setup since being built.  My thunder tiger was very similar.  Works great though.  I want a second e5 assembled now lol.  One 6 cell and my current 12 cell setup

[curmudgeon]

For me my tail is assembled as per the instructions.  I can set end points the same but it would leave extra travel on one side like the op.  For centered slider on shaft the bell crank would be off 90deg

Correct.  If I have the bell crank at 90° to the tail case, the tail slider will not be centered on the tail shaft, so the left and right travels will be unequal.

I think I'm just going to leave the tail assembled as per the instructions manual (16mm servo arm hole, bell crank 90° at neutral), and then adjust tail slider travels as much as possible without binding, and not worry about the actual tail slider travel numbers.

[Chris Wall]

If memory serves me correctly, I am around 95 and 105 in the Vbar Control on my E5, just re-setup an E7se and I was pretty much dead on at 106/108 on it.  I'll have to take a look tomorrow when at the field and see how close to 90° I am, as I normally have more difference when setting up tail!!!