2 Piece Push Rods

[Pete Ford]

I'am after a set of 2 piece (inner & outer) pushrods for a flying wing, in order to run them inside the wing, much like the pic below...

 

 

Where can i get some from?

Edited By Pete Ford on 29/04/2010 15:17:10

[Erfolg]

Pete

 

I have looked at the picture and re-read your description. Yet I cannot workout what you have.

 

At first I thought it must be some kind of Bowden cable system. I then looked at the picture and thought, perhaps not.

 

I then thought what advantage two tubes would provide, say over a solid push rod! Perhaps reduced weight. But the saving would be so small as to be illusory.

 

Structurally i could see no advantage.

 

So gives a clue Pete.

 

Erfolg

[Pete Ford]

I'm building a new wing and like the idea of having the push rods hidden in the wing (as above), currently my pushrods are as below (not my pic)...

 

 

I just think that if they were hidden it would look alot neater and also keeps them out of the way when in combat. As the servos remain at the front of the wing im looking for an inner and outer pushrod system to run them through the wing.

Edited By Pete Ford on 29/04/2010 15:38:21

Edited By Pete Ford on 29/04/2010 15:38:36

[Pete Ford]

Found some...

 

http://www.rcaircraftmodels.co.uk/2039_1_1022178.html

 

And i only live 1/2 mile from there

[Biggles' Elder Brother - Moderator]

Pete, just so you know their usually called "snakes". If you'd used that expression I'm sure Erfolg would have twigged to what you were after.

 

BEB

[Pete Ford]

Thanks, its hard to find/describe something if you dont know what they are called!

[Erfolg]

Ahhhhh!

 

Yes snakes!

 

Some old foggies call them Bowden Cables, if they have a wire cable inner.

 

In my opinion. Goldberg "Goldem Cable"are the best Bowden Cable type. Very thin, extremely supple.

 

Efolg

[Erfolg]

Scrub Goldberg insert Sullivan.

 

There is an issue with the fittings supplied. They are not 2mm, but a USA size and pitch etc.  The cables themselves are the best "Bowden Cable " type though.

 

I do use Sullivan "Golden Rods", these are far chunkier and consequently visually more predominant.

 

Both seem to have similar frictional properties, both initially and later in life.

 

Erfolg

[Erfolg]

I have had a thought, if you are relatively new to using Cable/snakes, you may be unaware of installation requirements.

 

The snake concept makes use of the phenomena, that a slender object, even when bent,  when pulled will try to go into a straight line (tension). Also that a slender object, say a garden cane, when subject to compression, will try to cripple/bow.

 

The snake makes use of these phenomena that we have all observed. The control wire is placed inside a close fitting  sheaf/cover/tube.

 

For successful installation, it is essential to fix both ends of the outer tube. Why? Simple and ingenious (in my opinion), this is to ensure that when the inner wire is put under compression/thrust and it tries to cripple, it puts a load onto the outer tube, this puts the outer into tension,(any extension is very limited at the loads of models) which prevents the crippling of the inner and ensures that that the compression load is effectively translated as thrust. Note that means both eds must be fixed.

 

Many say it is essential to fix along the length. Looking at cars/bikes as examples, you will often find bowden cable/snake applications. On bikes, on the brakes, cars on the clutch. These examples are generally used in tension, but are often only fixed at the ends, if fixed intermittently along the length , it is just to constrain.

 

 

[Phil Claridge]

if your control run is straight you can use carbon fibre tube with 2mm internal dia and ordinary wire pushrods, very strong