alternative sail designs

The Forum for RacingSparrow radio controlled yachts. Focussing on build your own scratch building, free plans for download and a comprehensive builders guide book.

Best wishes and happy sailing, Bryn Heveldt.

alternative sail designs

pinkelephant
Joined: 23 Nov 2016, 14:53

23 Nov 2016, 15:06 #1

What happened to the "alternative sail designs"? I bought the book some time ago and eventually built three with my grandchildren. They sail very well but often there is too much wind. Before I get down to designing reduced rigs, with the need to carfully calculate new centres of effort etc. I looked to see if anybody else had done so as the sailplan in the book states "for free alternative sail designs goto http://www.racingsparrow co .nz". Can't find that exact web address, nor alternatives on the forum.
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racingSparrow
Site Admin
Joined: 06 Sep 2012, 03:27

23 Nov 2016, 18:45 #2

There is a "B" rig design in this PDF:
http://www.racingsparrow.co.nz/assets/U ... RS-750.pdf

it's on the free plans page here:
http://www.racingsparrow.co.nz/theboat


Bryn.
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pinkelephant
Joined: 23 Nov 2016, 14:53

26 Nov 2016, 16:47 #3

Many thanks for reply. However, although the B-rig has a 19% reduction in mast height, the sail area appears to be only reduced by about 10%. I used to race A and M class yatchs in the 1950s. We had an exposed seaside lake and sailed in allmost all weathers, we had 1st, 2nd and 3rd rigs with sail areas (guessing) about 100, 80 and 60%. I don't want to have to shift mast step or shrouds of the Sparrows, so will have to do the effort of working out my own centres of effort etc to keep the heading the same.
Whilst on the subject of sails. I was unable to obtain the material that the design called for, so returned to the sytem we used in the 50's. I obtained lightweight woven polyester material, stretched it over a frame and sprayed it with diluted polyurethane floor varnish. This drys quickly to produce a waterproof, firm but flexible material that can be cut easily and doesn't need hems as it doesn't fray. Choice of colours is enormous, we use off-white, dark red and orange at the moment; I have blue awaiting the new reduced rig design, so had best get to it myself.
Tony.
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racingSparrow
Site Admin
Joined: 06 Sep 2012, 03:27

26 Nov 2016, 19:43 #4

Although the B sails are not a huge reduction in area they do depower the boat significantly. The bulb on a racingsparrow is very heavy for its length making large power reduction unnecessary.
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