SERAFIM

I'm building a GP Super Decathlon and I have installed the pushrods and the throws of all the surfaces are about double than the recomended. The clevices on the control horn on the surfaces are installed in the outermost hole, so if I want to reduce throws I have to move the other end to a hole closer to the servo center. I can also limit servo travel using my computer radio. Is there a reason why I sould move the clevise or is it just the same if I use the radio? I'm asking that because I don't use a z-bend at the servo, but a sullivan clevise, so if I put it closer to the center it might touch the servo when fully deflected.

Anyway, if anyone can help me with this please let me know. I hope I made my problem clear, because I am in Greece and English is not my maiden language. Thanks

Ed Smith

IF you have a computer radio then leave the surfaces as they are and control the surface movement with the dual rate function. You can then set up two different rates to suit your needs for flying and have the ability to switch from one to the other in flight.

As an example I do this with my Pylon racers. For normal racing we use very little surface movement. Taking off from pavement I use the flying set up. for landing though I need a little more aileron so I switch to a higher aileron rate. Taking off from grass I use a higher elevator rate to prevent nose overs, as soon as it is in the air I switch to the lower elevator rate.

Does this help?

Ed S

SERAFIM

Yes, it helps, thanks. I just wanted to know if less servo arm movement is bad in any way. As I understand its ok

BarracudaHockey

My Feedback: (11)

You loose some servo resolution and mechanical advantage if you shorten your ATV's (end points) too much.

Try for as close as you can with your mechanical setup, then make final adjustments with ATV.

Some will say its not a big deal, just fly it, but I like my stuff as close as possible before I goto programming.
Andy

CGRetired

My Feedback: (1)

That seems to back up what all the people I fly with suggest. Being new at this, I take any and all suggestions and see what works for me. So far, though, I have successfully built and flown four aircraft and I solo'ed in August. Each one of them got better in the build process. One point that was always stressed was the very issue of this message thread. So, I spend a bit of time, more than I think would be the normal, setting up the control linkage so that the mechanical portion is as close to realistic as possible then do the EPA adjustments to fine tune it. Makes sense, too.

Dick.

Ed Smith

End point adjustment is OK but it cannot be changed in flight like dual rates. The two functions have a slightly different purpose.

Ed S

SERAFIM

Thank all of you guys for the feedback. All these were my thoughts too, so I wanted to know what the rest of you thought. The question is, how important is loosing resolution by 50%? Keep in mind that I will just do sport flying. I have read some really bad comments on the GP Super Decathlon on this site, so I'm afraid I'm going to crash it realy soon. I hope I won't, because it's my first kit, it has taken me almost a month of afternoons to finish. I'm almost done now and if the weather is good I'll go flying the weekend

Scar

My Feedback: (3)

From your last post, I would make these recommendations.

Set up your dual rates at half the recommended, and at the recommended travels, for low and high rates respectively. If it is not difficult, move the servo clevis to a hole on a smaller radius, first. You can trim away some of the servo arm, if need be.

Taxi the plane a few times, to see how much elevator is required to let the tail come up without nosing over. I recommend you get proficient with taxiing with the tail in the air, and that will require less power, or shutting down the power when the tail comes up.

When you are proficient with taxiing, and know what speed the tail comes up... learn to add more throttle without letting the plane lurch off the ground. This plane will lift off before it has attained flying speed. That usually is followed by a snaproll, at waist level. To avoid.... gain plenty of speed before allowing the plane to lift off the ground.

At that point, the plane flies like most aerobatic planes.

Good luck,
Dave Olson