hey I'm going to remove those clips in files as to not take up the last bit of space. So down load them before I remove them if you want.
I posted the unedited clip on daily motion
http://www.dailymotion.com/video/xqtr23_double-wing-reveres-flow-sail-boat_tech
--- In harryproa@yahoogroups.com.au, "tsstproa" <tsstproa@...> wrote:
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> Did a second test with adjustable extended steering boards. Also put design waterline marks on hulls. LH 12/15 WH 6/9 inches fIrst line represents intended ride height second or top line is heavy.
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> Static test in tub showed 2 oz in WH hull to sit right on intended waterline. Leeward hull sat light. with the 4 oz it sat heavy and made model list to windward seen on level gauge sitting on cross beam.
> I see the problem now the deeper rocker of leeward hull needs to displace more water to ride level with weighted windward hull to sit level. The fix for more weight in wind windward hull would be to offset windward hull on connecting beams by raising beam connections on ama by 1/4 inch. So when sitting static on table the windward hull sits higher and leeward sit lower canting to leeward. Conclusion underwater plane effecting helm balance. Heavily weighted draggy windward hull not good
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> Seeing the model in action I can say this for sure the rockers should be reversed on hulls. LW 12'' TO 6'' AND WH 6'' TO 12''. or maybe both hulls at 8'' rocker used loosely here, fare curve constant radius from bow to bow not a three staged rocker with flat mid and turned up tips at the end.
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> On this particular model:
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> Leeward hull should have a shallower rocker. The first part of the models acceleration you can see the webble/wobble effect or pitch forward before it accelerates. The flatter rocker should help to engaged the acceleration of the model faster with out the wobble by engaging hull resistance from sail force sooner.
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> Windward hull should have more rocker getting those hull bow keel tips out of the water for less resistance though the water also with less buoyant bow ends elevating any negative pitching onto leeward hull.
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> post a few clips in files to show
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> --- In harryproa@yahoogroups.com.au, "tsstproa" <tsstproa@> wrote:
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> > Steering boards, of all models when sailing are set to have 0 DEGREE AOA. Model should sail with hands of stick in a straight line on all most all courses once under way.
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> > The steering boards on this model were 7''l x 1 3/4''w , 4'' sat below waterline. I cut 1'' off each board for a now 3'' below waterline. Funny thing with this model its producing lots of weather. Model does not have a neutral helm . First I thought it was the added weight , 4oz to sit on deepest waterline for maximum displacement designed on windward hull. So I took out 2 oz and tried same thing no neutral helm there was a difference but not significant. So took out the other 2 oz's still no neutral helm and winds were decreases even yet should have helped. So with all weight out added a lump of sand to designed maximum displacement for leeward hull and it help but again not by much and slowed the model down. The maximum displacement for leeward hull is more for active sailing loads not static loads. Its an anticipated maximum sailing heel force of what the under water plane will look like.
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> > The model did show a higher turning into the wind tendency than other models but with the longer boards always had a positive steering at slow speed and once under way a neutral helm.
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> > I'm thinking rockers wrong on windward hull, not enough rocker. Or leeward hull has to much rocker. Either way as they are, are a miss.
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> > Oh yeah lots of leeward hull bottom bow slap in moderate chop ouch...It was making an actual audible sound.
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> > --- In harryproa@yahoogroups.com.au, "tsstproa" <tsstproa@> wrote:
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> > > Did a new model with rockered 36'' hull 36' in real life and a 24'' both have identical rocker curve and are 4'' or 4' tall at center. If you were to place each hull next to one another on a flat surface the windward hull follows the rocker contour of the leeward giving the windward hull, the shorter hull, taller stems. Both hulls are connected to were they sit level on with both keels touching flat table top.
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> > > This gives roughly a 1'' lift in keel bows on leeward hull and a 1/2'' lift in keel bows of windward hull.
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> > > Hull Designed to sit on a 8 - 12'' waterline on leeward hull and 6-10'' waterline leeward. Scale model would be 3/4 -1'' and 1/2 -3/4 inch roughly.
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> > > So far I'm not convinced that this set up is the best. It seems that the windward hull is pushing more water. Seeing the bow wave is higher and more predominate than the leeward hull when sailing.
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> > > Comparing to what I have in existing tests of rock no rocker hulls the no rocker seems to be better in someways, not all mind you, but better in what I'm looking for.
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