chuck l

My Feedback: (17)

Would it work to glue a piece of brass tubing at the exit of the wires for a rudder pull/pull setup? The frame of the fuselage by the rudder is a little cramped, so instead of a slot, I'm thinking of guiding the wires with the tubing. The deflection of the wire would be minimal. Has anyone done this before?

Chuck

Gray Beard

My Feedback: (-1)

I use the yellow, or color of your choice, nyrod push rod. Anything metalm will chafe the wire. I use plastic coated stailless steel fishing leader to make mine up too.

scale only 4 me

My Feedback: (158)

+1,,, many times

SeamusG

Are your pull-pull wires crossed between the servo and the rudder or straight (not crossed)? I ask because I've found that you can minimize the chaffing that GB talked about by crossing or un-crossing the wires.

chuck l

My Feedback: (17)

Thanks for the help guys. I'm going with plastic, yellow since it is a Cub and it is all I had. The wires have to be crossed to have a chance of working.

Chuck

Gray Beard

My Feedback: (-1)

I do it anyway I can, some fuselages lend themselves to straight and some require crossed. I will often run the Nyrod from end to end but it isn't required. You can just run the wires out the back and through a couple inches of the Nyrod. On some planes it is just easier to be able to run the wire all the way through the Nyrod from end to end.
Think of it as an Easy Button.

Rodney

I do pretty much as Greybeard does. I use a nylon tube on most of mine for the full length as that makes it easy to replace the wire if ever necessary plus, if properly anchored, you can negotiate some rather complex rerouting should you need to go around some obstructions between the servo and the surface being controlled. I always make sure I have a little positive Ackerman set up on all my pull-pull with just enough tension to eliminate any slack in the wires when at neutral position. I've done it that way for years on all my 1/4 scale stuff with never a problem.

Gray Beard

My Feedback: (-1)

I knew someone was going to say Ackerman. I was setting up pull/pull systems long before I even heard the word. I never have had slack in my lines at neutral but when I use the rudder, a bit of slack on one side isn't going to hurt anything in a CUB. I do take the time with precision stunt planes though. It is nice to know what it is and how to set up the system correctly but if you have any slack on the opposite line when you operate the rudder don't sweat the small stuff.
The idea of Ackerman is to have no slack in either line when you operate the rudder so the pull to the opposite side is instantaneous. You can spend a lot of time setting it up correctly, some fuse designs just don't lend themselves to getting Ackerman easily. In an easy floating plane like a Cub don't give it a lot of thought but it's a nice plane to learn with.

Jacobs Jasta 7

+3


Pete

KitBuilder

I flared each end of my nyrod as well... I'm building the BUSA 1/6 N17 and putting the elevator pull pull in a scale location as best I can which throws the whole ackerman thing out the window. Rudder does not have the same issue. I have the contral amrs and servo arms the same width at least. I haven't seen any slacking etc of the lines on the elevator.

daveopam

My Feedback: (9)

Not trying to educate any of the posters in this thread, but others read these and do not post.

Something that was not mentioned, I would worry about using any sort of metal exit for a pull/pull setup. This could be a potential source of RF noise and cause radio problems. IMHO
Using the plastic tubes as mentioned above would eliminate this potential issue.

david

dignlivn

+1

Bob

Gray Beard

My Feedback: (-1)

I'll give that a +2 but I have never been hit with RF with a glow powered plane. I know it is the RX that is hit with the noise but I have seen wire LG rattling around and metal push rods vibrating and never seen a glow powered plane hit with RF.
I know it should be posted in it's own threat but I would like to hear from people that have been hit with RF over the years with glow powered planes. Just because I haven't seen it doesn't mean it doesn't happen.
Over the decades I have gotten hammered with RF using gassers of all types, Mags and electronic ignition. I lost my last summers build on maiden due to RF, a slit in the plug boot was arcing across the ground strap. I have just never seen it with a glow plane.

daveopam

My Feedback: (9)

The GB Ult I have now had issue with RF. It is a ARF and not a kit. On the ARF the top wing bolts on. It would be fine some days and terrible other days. Once even throttle up while I taxied in. The problem turned out to be in the rear wing bolt. It would sometimes vibrate loose. Every Time I had a hit in the radio, the bolt was loose. If there is a different explanation I don't know what it could be. Since I switched to a nut with a nylon insert, the problem has never reappeared. That was over a year ago.

David