wire drives verse flex drives

[Steven Vaccaro]

One reason is the is less area with friction. I hear guys say that there is only one point where a piano wire touches the brass tube, where a flex will rub a great deal of it.

[Simon.O.]

Another reason that may have an effect on speed is less drag, this is for tunnels / cats / hydros where the shaft exits the bottom of the boat and then goes to the strut.
Have a look at the frontal area of a Flex setup vs the area of a wire drive setup.
Here is a pick of the wd in my cat.

[Jeff Wohlt]

Sorry, been out for a bit.

I do make the type with mechanical and glued. I sell these mostly for SAW racers but they do not come apart. Even the glued ones have had very small problems over the many, many out there. I have also tried using some new gunsolder and have to say I can't break it....twisted the carbon wire in loops and never did break the solder in the stub.

I do not make them all the way thru...reason is it is hard to find really straight tubing for this. I do lathe drill them over an inch deep and more.

Many are now using the .078 for bigger power. The .062 is still a great system for up to 12 cells. With the power available now it is better to use a little bigger as long as you are not bending it hard.

To see what happens to flex cable...apply torque when not in a stuffing tube....it want to become straight but can also try to knot up. When this is happening in the stuffing tube you can see why a wire is better. Run a cable without teflon and listen....it rubs all over the stuffing tube and not 1 or 2 spots such as a wire.

The hard straight shaft is the most efficeint means to drive a prop but not many can use them...wire is the next best option.

Also, many do not look at the strut...bearings make a big difference. As the prop torques it puts pressure on the bushing at an angle and this also create resistance.