Barry Cazier

My Feedback: (17)

I'm curious about the pros and cons of dual elevators. I have several planes with each style. Do any of you program the elevators to mirror the ailerons? Obviously the reduction of one servo in single elevators is an advantage in weight. And I can't really tell any difference in control athority with the dual elevators. I guess you would have to have a stronger servo on the single surface, but are there really any flying differences? Are some of you doing some weird programing that really makes certain maneuvers easier, more impressive? What do you think? All of the planes I have are 40 to 90 size. No large scale. Are the dual elevators more important the larger the plane?
Thanks
Barry

CJKling

My Feedback: (1)

A guy from my club had an F90 with dual elevators and he could switch them to move in conjunction with the ailerons, however the roll rate on that plane was so fast already that it really didn't make much difference.

tIANci

Barry - dual elevators are good on big planes for sure, allows each half to be carried by one servo. Push rods sometimes are a 'bad option' due to the way the plane was designed. This is relevant to small planes too. Hence with dual elevator servos it is direct for each moving surface area. The saving in weight is negligable if its in something of a 40 sized plane. The extra couple of ounces is hardly anything. I have flown many planes with an elevator pushrod, if its properly done the elevator has hardly any noticeable slop even for 3D.

goony

on my harrier im using dual elevators and a Y lead with a servo reverse but ive noticed that i get more throw with 1 than the other and this makes it screw out any ideas WHY?





goony

aviti

My Feedback: (54)

Most likely your geometry isn't perfect. You need your horns to be the same distance from the hinge line, same height off the control surface etc. If anything is off just a bit, then it will show significantly on 3D throws. Another solution is to mix 2 channels on a computer radio and then you can set you endpoints to match with the radio. You may not have a radio capable of this though.

Finally, beware of the reversing Y harness. I tried one once and it changed the neutral trim settings as temperature outside changed. It would raise or lower one elevator half which was not good. Others have seen the same thing

goony

Aviti you could have a point there as I made sure it was perfect the night before and noticed the different throws this afternoon after being out in the sun allday ill check tommorow morning and let u know how it is


goony

AcroJo

My Feedback: (1)

Interesting subject. On split elevators I've always used a program mix. Tried a reversing Y harness once with good results as it was an adjustable one and the centering held. On my current project, I chose not to mix, using a standard Y harness with one 'reversed' servo from the manufacturer. Although my parallel adjustments are limited to mechanical, the travel of each are equal and center well. Time will tell. Joe

Barry Cazier

My Feedback: (17)

I've always used the computer radio programming on my split elevators. I've never used a Y harness. But I honestly can't tell any improvement with my Yak, UCD, Showtime over my Mayhem (which only has 1 elevator servo) It seems to do a waterfall or harrier just as easy and with same authority as my split elevator planes (not as pretty for sure but it's not an issue with the elevator) I haven't used any sepecial programming to do any special 3D stunts with an odd use of the elevator. I'm just wondering what everybody else found. On the Funtana, for instance, it would be nice to use only one elevator servo. The loss of weight on the tail of that plane would really help it. Anyways, thanks for the information so far.
Thanks
Barry

waco4444

Can anybody tell me how to set up my radio to mix two elevator servos' on my u-can-do? I have a Hitec eclipse 7. The slave servo always stops to soon?

jon595

My Feedback: (2)

Sillyness posted this a while ago in the GS forum:

Set your ATVs to approx 130% up and down (130% is for JR... may need to use slightly less on Futaba or Multiplex) to allow room for subtrim. Then I roughly center the surface with subtrim. Measure up and down throw. If you have more up than down, then shorten the pushrod (and vise versa). Now, re-center the surface with subtrim, but do not touch the ATVs... leave them alone at 130ish%!!! Re-measure up and down throw and repeat the above proccess until the surface moves the same amount up and down. Your servo arms will likely be tipped slightly toward the rear when done, but it depends on your geometry. If you end up using excessive subtrim you may need to rotate the servo arm 1 spline one way or the other. Look at your servo monitor page to make sure you aren't over-driving a servo (i.e. a servo stops before the stick reaches full travel). To get more travel both ways after they are matched (up & down) you need to move the clevis height on the control surface

The result is a setup where both halves will travel at exactly the same speed and they'll track together perfectly throughout the range of motion.... very linear. To get more travel both ways after they are matched (up & down) you need to move the clevis height on the control surface


It might take you 30 minutes to do the first one, but after you learn how to do it the second one is a piece of cake.