When i saw the first pic of NED666 i noticed that the rotator arm has moved from above the boom to the mastbase, is this part of the evolution? Are all newer blades delivered in that way, and what is the difference in handling?
From what i have read is the mastrotation essential to the alu wingmast and not neglectable, thus is has to be easily accessible.
That is true.
Also the mast base rotation arm allow you to run the lines underneath the trampoline making the tramp a little more clean.
In 2-up the arm at the base could be knocked with the knees at manouvres, or is this a minor point?
I've never experienced such a thing. The circle travelled by the arm seems to be well out of the way of where you place your hands or knees. Afterall it is only 30 cm behind the mast. I did however get knocked on the head by the rotation arm that was fitted just below the boom. As a result I consider the low rotation arm to be the better setup from the viewpoint of bodily harm. Also I rather hurt my hand (if that was indeed in danger) then poke an eye out. On the Taipans I really disliked the rotation arms that were just below the boom. It would also hook on your life vest and such.
Advantages of a low rotator arm setup. It is simpler to produce and it is cheaper, also less holes in the mast. It requires less blocks and less expensive cleats. Also it gets rid of loose hanging control lines that often find their way into you spi ratchets. As a matter of fact a low setup moves the rotation control lines to under the tramp, removing them altogether from the tramp which is already cluttered with other lines.
Drawbacks. Well if you travell out the main then you pretty much have to adjust your mast rotation as well. There is somewhat less need to do so with the "just below the boom" setup. Personally I found I don't travell out on the upwind legs so one setting is always the right one here. The only other leg that you'll encounter will be the downwind leg where you have to readjust the rotation angle for anyway.
The rotation arm I have is indeed really simple to make and any homebuilder can do it. Plain hardware store items got the job done.
personally I think there is little difference between both setups in the way of performance but alot in ease of production and cost. So I decided for the low setup.
I hope this helps.
Wouter
Wouter
