How can I ensure Equal throw for elevators halves???
 

This is my first dual elevator set up using an individual channel for each servo actuated elevator half: in my case using a new Airtronics RD-8000 which uses channels#1 and # 7,to do the job---After first "eye balling" the throws between the left and right elevator halves, it became readily apparent I'm not at all sure as to the accuracy using the 'sighting technique' to insure that the elevator halves are equal in travel through their range of travel either up or down in their deflection,on my Great Planes Wagstaff. I recently purchased the Great Planes throw meter which uses a protractor to measure degrees of throw HOWEVER---It appears rather (in accurate) for what I'm trying to accomplish..
WHAT TECHNIQUE /THROW METERS DO I NEED TO ACCURATELY ADJUST FOR EQUAL ELEVATOR TRAVEL THROUGH OUT THEIR RANGE OF TRAVEL?
Thank you!
Richard Mcfarland AMA52920

RE: How can I ensure Equal throw for elevators halves???
 

Richard,
Get a CRC Throw meter and measure the rates directly in degrees. Get it to withing 1/4deg on the meter and that should be fine. I am sure you will have to do some adjusting. I always had to.
RickP

RE: How can I ensure Equal throw for elevators halves???
 

Richard- easiest way is to merely attach (tape) two short rods (carbon rods work best- light and straight) to each elevator half and angle them so that they almost touch together at a single point directly behind the rudder.

As you work the elevator up and down you can see if the two rods continue to stay "together" or if one is higher/lower than the other and make adjustments accordingly.

Dave

RE: How can I ensure Equal throw for elevators halves???
 

Do what Dave said.

RE: How can I ensure Equal throw for elevators halves???
 

I put attach a straight edge (ruler) to each elevator half and let them come together behind the rudder. Then as I move the elevator I can check throw as well as tracking. I have found that I can have one without the other.

RE: How can I ensure Equal throw for elevators halves???
 

Thanks-that helped--

The more I've learned the more I've forgotten..:)

RE: How can I ensure Equal throw for elevators halves???
 

g

Do what dave said it is the easiest way to make sure your elevator halfs are moving together acuratly. use the crc throw meter to set max throws . Use the rods to check travel and compair
the halfs. When you were at the judging seminar this year george hicks discussed this approach.
remember to get rods long enough to get past the rudder and place them so they come together behind the rudder. Right away you'll see if there working together correctly.

Tony Fandino

RE: How can I ensure Equal throw for elevators halves???
 

Thanks all and hope this post is helpful to others as well--

The more I learn the more I forget[sm=lol.gif]

RE: How can I ensure Equal throw for elevators halves???
 

Hi Richard,
To take this a little bit further- as Geistware says its not uncommon to have equal throw yet have the travel not full synchronized thru out the full range. At our IMAC seminar a few years ago Rob Sarlan, Dave and crew discussed a) using Hitec digitals which can be programmed for travel speed and endpoint b) a bench jig with LARGE scale travel indicator c) having several servos on hand so one could pick ones that match well as there are significant variations in travel speed and intermediate positoning
So to some extent its a matter of how serious you are... if you want to discuss this more I be at the field both Saturday and Sunday
C U there I hope:D

RE: How can I ensure Equal throw for elevators halves???
 

Hey Steve,
Well I'm not replacing servos per say soI will see you at the field. In mean time I'm checking using the method suggested by Dave to at least ensure they are in the ball park;should see you this weekend--Richard