Dave Presta

My Feedback: (3)

I decided to go a more direct mount then the internal stock system.
First I cut a hole just big enough for the servo to fit through the fuse, mounts and all, just in front of the rear spar mount. I let the servo arm hold the servo in position as I fit mounting blocks in from below.

Dave Presta

My Feedback: (3)

the next two pictures are of the bottom of the rudder. The first one is how it comes stock, the second is my mod. I cut out the rod and routed a channel in the bottom of the rudder. Then took the stock mechanism, took out the set screw and installed a long bolt and let it bottom out on the collar, relieved the hole a bit then glued the new system in from the bottom.

RonLongAZ

My Feedback: (29)

Nice Mod Dave keep up the good work.


Ron

sweetpea01

My Feedback: (10)

Do you have a few pics of it on the plane and hooked up?

Dave Presta

My Feedback: (3)

notched the rudder and inset the control arm

Dave Presta

My Feedback: (3)

Here's how it lays out when done

Dave Presta

My Feedback: (3)

I used "Push Pull", so both sides of the rudder are identical and have solid pushrods.

Dave Presta

My Feedback: (3)

A couple of notes.

I did all of this with the rudder hinges glued in, so if anyone decides to utilize this method on an already flying plane then it is completely possible. You would probably want the pipe out so you can reach in from the bottom to fit the servo mounting blocks.

Very important. Do not use any servo wider then an 8611A, and make sure not to make the cut out any wider then the servo...it should squeeze through nice and tight. Take your time and make sure to center the cut out so that the openings do not protrude past the outline of the vertical stab. My original intent was to mount the servo upside down in the vertical stab, but after some measuring I decided that it was way too tight of a fit to start shaving the fin. The advantage of the servo being in the vertical of course would be that you do not have to take off any of the linkage when removing the vertical.

Other then that, its pretty straight forward. Make sure to anchor the control arm in the rudder with a long bolt and rough up the metal when gluing.

This is not a "fix" or an approved Skymaster idea, I came up with this on my own because this is how I wanted to mount it.

Take care,
Dave

AndyAndrews

just curious, why would you do that mod in light of the existing mod that has been proven effective? Moreover the other mod is all internal.

Andy

quist

My Feedback: (198)

I would only use one push rod. With that geometry you could have some binding at full throw. It is easy enough to check, disconnect one side, go to full deflection and reattach the pushrod.

Dave Presta

My Feedback: (3)

Checked it, its fine. Thanks for the heads up though.

Dave Presta

My Feedback: (3)

I don't like the internal method, the mod I believe was not a change in design just a different shape to the notch in the torque tube. Sometimes I am known to fly a little hard, and I did not have confidence in the stock system. Please realize that I am not saying that there is a problem with the current system, I have no experience with it. Besides I'm not too worried about having an external linkage, this thing is painted in the mold and has seam lines....and Arf's are not allowed at Top Gun anyway! Function is beauty in my opinion, and my system gives me a whole lot more warm and fuzzy's then the stock setup.

JetsRC

Nice setup Dave... Good idea...

Michel

NickC5FE

My Feedback: (31)

Nice work Dave. Nick

Billy

My Feedback: (15)

Nice job Dave. That should hold up fine. Get er done.

Billy

WhoDaMan

My Feedback: (164)

Ok big D,,,, let me chime in here ( Ding ) all done bud, Almost ready to join you in the build,,,, or is it Nick that will join you

Dave

icepilot

Hi Dave -
Nice mod, and a good idea for peace of mind!

The mod that Andy is referring to is the one my friend Tom came up with which is a completely new design - the SM change
may be strong enough, but since I had flutter on my plane, I did the same mod as Tom with the tubing and the piano wire,
which is super strong, absolutely no play and allows me to fly hard without the fear of flutter. For anyone intending to make
a scale model, I can recommend this mod.

Tor

drdoom

My Feedback: (9)

Dave. I did the same thing to my 1/8 JL F-16. but I only did one side and it is 5 times more solid than original.
F-16 rudders will flutter if they aren't solid. Not shown here, is the .016 safety wire holding the clevice and ball joint from coming off.
Great job.

Dave Presta

My Feedback: (3)

Only one side would be just fine I think, but I wanted it a little more solid then that.
Yeah even back in the Byron F-16 df days I battled with rudder flutter, until I decided that I did not need a working rudder and hinged it with some solid carbon pushrods.

Dave Presta

My Feedback: (3)

Here Kenny, this is what I was trying to explain.

KFalcon

My Feedback: (18)

Thanks bro.

jet time

My Feedback: (75)

Great job as usual Dave. I saw the last one and it felt and looked excellant. You do good work! See you at best in the west bro!
Lowell