Tail servo/slider set up question.

[FMJB]

I can not get my tail slider to have an equal amount of throw.
(GY401/ S9257 servo boom mounted).

Right stick has too much throw, but left stick does not have enough throw.

"In rate mode" the servo does not return to center after moving the stick left then right.

How am I supposed to center the slider when the servo will not always center?

I set this up a while ago and it worked fine. I've had a slow nose left drift for quite a while so I'm not sure I have ever had it set up mechanically correct as far as the slider throw).

Recently had a small crash, now (with more knowledge about how to set up a RC helicopter) I can not get the servo to return to center for the mechanical set up.

My B400 flies OK the way it is, but it's not right.
Got any advice? any clues?

Thanks,
Bill.

[schoep]

Sounds like the servo arm isn't centered in rate mode. unscrew from servo and reinstall centered then readjust tail slider for center. Then try the rudder again. Did you put new gears in servo? Servo on boom? Servo shift back in mounting?

[Arsenix2001]

I dont quite understand.. it would be impossible for you not to center it mechanically. Take off your servo arms, linkage, everything... turn radio/gyro on with radio in HH mode.. make sure you have NO subtrim or trim on radio and flip your HH/RATE switch back and forth RAPIDLY 3 times ending in the HH position. Flip back to rate mode, NOW put your servo horn onto the servo so it is best 90 degrees to the servo. Attach your linkage again and MECHANICALLY adjust the linkage to get an equal amount of tail shaft showing on either side of the slider... go full left and full right in rate mode and adjust limit pot accordingly. I did this and didnt even need a click of trim for flight, rebinding or any of that whooey. You may need to physically cut or adjust your linkage rod if you do not have enough threads availible to adjust.. Simpley cut off the ball link that goes to your servo... sand tha graphite rod down a wee bit, and get yourself a standard ball link for the head. you will have to drill out the hole a TINY bit to get it to fit in there SNUG, and use some C/A to secure it... hope this helps.

[schoep]

Is your sub trim still 0 in setup? Dose the servo stop at misc. places in rate mode?

[FMJB]

Originally Posted by schoep

Is your sub trim still 0 in setup? Dose the servo stop at misc. places in rate mode?

Subtrim is at zero.
Yes the servo stops at misc places in rate mode.

After centering the servo arm in rate mode it does not return to center every time after cycling it.

[schoep]

Have you taken the servo apart after a crash

[FMJB]

Originally Posted by schoep

Have you taken the servo apart after a crash

No I have not touched the servo.

This servo has seen only a few very minor crashes.

I'll follow Arsenix2001's sugested set up and see if I just did it wrong.
I've never adjusted the "limit pot on the servo. Didn't know it had one.

[Punkin71]

I'm having the same problem with the same setup you have. 401 9257 servo boom mounted. I think it is caused by slop in the tail. I've had my 400 for about 4 months now and there is quite a bit of play back there. decided to go with a trex tail setup, it should arrive in a few days. hopefully this will line things out.

[Punkin71]

also it seems I've had to lower my gain quite a bit to stop the wag, i'm dow to 61.5 comared to 68 when I first got the 401.

[Arsenix2001]

Originally Posted by delbie623

also it seems I've had to lower my gain quite a bit to stop the wag, i'm dow to 61.5 comared to 68 when I first got the 401.

That would indicate you might be getting the slop you are concerned about... check all your mechanical links...

[Arsenix2001]

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[FMJB]

Well I figured out why the servo would not center in rate mode :o,
I had both 1 and 0 set above 50 so I was not in rate mode at all. Forgot I did that and didn't check it. DUHH!

I do still have less tail slider travel on one side than the other, but it's WAY better.
At least the slider is not over traveling, and I got the slider centered perfectly.

( I machined a set of slider gages) then re-measured the center after getting it all set up and cycled it several times.

There's no "limit pot" to adjust on the S9257

I have HH set to 70 now and the wag is gone, still a slight bit of nose right drift but it's very minimal.

[Arsenix2001]

Originally Posted by FMJB

Well I figured out why the servo would not center in rate mode :o,
I had both 1 and 0 set above 50 so I was not in rate mode at all. Forgot I did that and didn't check it. DUHH!

I do still have less tail slider travel on one side than the other, but it's WAY better.
At least the slider is not over traveling, and I got the slider centered perfectly.

( I machined a set of slider gages) then re-measured the center after getting it all set up and cycled it several times.

There's no "limit pot" to adjust on the S9257

I have HH set to 70 now and the wag is gone, still a slight bit of nose right drift but it's very minimal.

Yes definatly make sure its under 50!! Thy limit pot is on the the GY401 not the 9257 my man... make sure your gyro is set to digital as well "DS". dont worry about getting it centered as much as having the end points max out on both sides using the limit pot... you want equal throw.

[FMJB]

Travel limit adjust for the servo is on the Gyro?
Guess I gotta go back and read the gyro manual.

Thanks.

[Arsenix2001]

Yes sir, you have a delay pot... (which i have set at about 15-20 to get alittle more gain out of it... it dampens servo movement) And you have a LIMIT pot, along with a REV dip switch and a DS/NR dip switch... make sure that switch is set to DS and use the ittybitty black screw driver they give you to adjust your limit pot to set servo end points.