KINGX

Hello, i want to get more travel for the contol surfaces of my plane. How should i connect the serno horn to the control surface horn? What holes should i use to achieve maximum travel for the surfaces? Are there any rules of thumb regarding the addjustment of surfaces travel?

PS) I am already at 120% in exponentials and cant get the surface travel i want.

THANK YOU.

Kenny R

To get the more throw move the control rod farther out on the servo horn and closer in on the control horn. Watch for binding.

AcousticTX

Hi, sure.. it is easy to adjust throw.

The rule of thumb is further OUT on the servo horn = more throw.

and

Further IN on the control surface horn = more throw.

Just balance it between them until you get the desired throw.

FHHuber

Umm... just change one or the other by one hole... fly it and see the result. Its possible to get too much throw.

If you still feel the need for more... try again.

If the change of which hole has no appreciable effect on how the plane handles at large stick movemnt... you have gone beyond useful control surface travel for the airplane. Time to reduce throw and increase control sruface area (or move up to a dfferent airplane)

MinnFlyer

My Feedback: (4)

Or (if you haven't already done it) seal your hingline gaps.

KINGX

How do i seal my hingline gaps? I know that in "conventional" planes (balsa ) i can use some sort of self adhesive tape. But one of my planes is a foamie with a foam rudder that is attached to the vertical stabilizer with almost a control surface long piece of higly adhesive tape.The problem is that the tape seals totally the gap at the left side , however at the right side there is still a 1/2" gap which i can not cover with the same tape bacause if i do the rudder will go "stiff" and wont turn either direction properly. What should i do?????? (the gap really disturbs the airflow).

FHHuber

Your foamie that uses tape as the hinge... the hinge is sealed by the tape... so its sealed already[8D]

Tthe 1/2 inch gap between fixed and moveable surface is a problem... could you try to re-hinge it with less of a gap? that wide flexible tape area is going to allow the hinge line to flex... that can reduce the ability of the control system to accurately positin the rudder. take your fnger and gently hold the trailing edge of the rudder as you move the stick and watch the hinge flex while the TE of the rudder sits still! that means... you have inadequate control not due to inadequate throw... but due to hinge flexing.

Can you post a pic of it? we may be able to guide you in the best solution.

KINGX

Here are the pics:

1)Left side perfectly sealed by tape which is also the hinge
[img][/img]

2)Right side, 1/2" gap
[img][/img]

FHHuber

OK... what you are calling a gap is a designed in bevel allowing the movement... its not a problem. (but the description sure sounded like a problem...)

That plane (just from the tailplane shown.. I can tell) is not a fast aircraft. the drag and turbulence of the bevel is not going to be a significant factor in the control system.

Thats one of the Kyosho appx 40 inch span electric Cessnas?

KINGX

It is a Kyosho Cessna 180EP , 52" wingspan powered by 600 direct drive motor. Actually i have sanded off some foam to allow for proper movement of the rudder, it was not correctly made from the factory. How did you recognize the airplane? Large foamies are not very popular....

I still think the gap will cause turbulant airflow....

nilo

Regarding the control surfaces, fix the the control surface horn as close as possible to the center of moving edge, where the control surface is attached to the fus. This way you also get more throw.

Nilo

FHHuber

I've helped a couple of guy with different Kyosho Ceessnas. one was the smaller (I believe discontinued) appx 38 to 43 inch span 3 channel

The other ws the one you have. Yours is better.

Really... the hinge line as is will be OK... There is a way to SLIGHTLY improve it by tucking a second layer of tape into the beveled area, so the 2 layers of tape stick to each other in the hinge line. This type of hinge is very durable and flexible (if the tape itself is not too stiff.. cheap clear packing tape is ideal)

Ther is a small amount of drag from that bevel... yes. There is also a slight amount of turbulence over the right side of the rudder from it... It would be a problem if the plane could exceed 50 mph.... but that plane would rip itself apart at that speed. (ain't broke... on't fix it)

The control horn is just a bit back on your rudder from ideal location... its not off far enough tobe worth moving it. You will have slightly more throw to the left than right is the only effect you will see. The difference will be small enough, that on that model you can ignore it. (some things just aren't worth worrying about)

siclick33

I am assuming that 120% Exponential is a typo.

Expo doesn't increase your throws. ATV or EPA does.

KINGX

120% EPA, you are right.

Stick Jammer

KINGX,
As mentioned by nilo, control horns should be installed with the pivot point on or as close to the hinge line of the control surface (at neutral) as possible. One thing that nobody mentioned was the basic rule of servo linkage. You should try to avoid ever having the control horn length (measured from the pivot point to the center of the hinge line) shorter than the servo arm. Doing so will put the servo at a mechanical disadvantage and possibly cause a failure. Having the control horn longer than the servo arm is fine, it increases the mechanical ability of the servo.