MAst Bend

[pegasus]

Having struggled with mast position and rake all season I tried this weekend to see what was happening with the mast. I was able to strap a Sports webcam to the front of the mast and pointed it skyward along the length of the mast.

What I saw was interesting and suprising! THe amount of twist and bending that took place was unbeleivable. I have speeded the recording up 5 times and reduced the overall time (2 hours of mast and blue sky is a little borring).

In case anyone is interested it can be found on youtube at www.youtube.com/watch?v=XcQryEyadNo.

Simon

[bertfatal]

Very interesting, what type of mast is it, it looks very soft at the top?

Richard.

[pegasus]

Its a Needlespar. THat is why it is very soft

Simon

[Meat Pie ...]

Hi Simon
Past "fashion" and thoughts have really majored on letting the whole masy bend reasonably uniformally with Needlespars[and SSS and Dolphin Masts]and this has worked very well in most conditions.Some issues develope as the wind strength increases however !
Currently most are trying to stiffen the lower section of the mast[up to the Hounds] and let the top section bend-off...gust responsiveness being the aim.
As discussed recently perhaps the easiest way to do this on a Needlespar is to lengthen the Spreaders and push them forward, even to the point [or a little beyond]inversion.Rig tension will restore the Mast to a more conventional shape !
With Needlespars the spreader bracket is fixed so some engineering is necessary to do this.
My particular interest is the sail shape when the mast bends especially in the upper half and certainly above the Hounds.
There are all sorts of things going on up there when the top section falls off sideways let alone bending aft and all have an effect on the Sail of course.
More luff curve is the usual remedy to accomodate a flexible mast.
The current excellent sail shapes offered by Banks[as you have]P&B and North have more luff round along these lines.Likewise Laura,s stunning "Slim"R&J is similarly cut.
Bendy masts can really de-power a sail but to hold them stiff or in column downwind and on reaches is desired if you can achieve it.

RW