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Author Topic: trim tabs and where to put them?  (Read 1578 times)

martno1fan

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trim tabs and where to put them?
« on: May 01, 2007, 01:44:00 PM »

hi as some of you know ive built a 48" deep v mono hull and im running a weedy 28 cc engine shes running well but ive just had some nice double trim tabs given and id like to know exactly where to best put them.i know they need to be 1/.16 up from the bottom but how far from the keel do i put them.seeing as they are doubles should i put them half way between the keel and the chine?.i want to use these so i can make small adjustments to suit the conditions also whats the best way to have them set as a starting point .i understand the outer ones are for cornering? and inner for straight running is that correct?.
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BJ

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Re: trim tabs and where to put them?
« Reply #1 on: May 04, 2007, 03:52:55 PM »

Drawings for AeroMarine's Challenger 48 show 2 pairs of trim tabs. Inner pair are supposed to control porpoising caused by bad weight distribution, outer pair trim the boat at speed (so I am told).
See the link for trim tabs on "real" boats http://www.bennetttrimtabs.com/tabsdo.htm.
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martno1fan

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Re: trim tabs and where to put them?
« Reply #2 on: May 04, 2007, 05:30:13 PM »

my boats ballanced correctly i just need some trim to stop any unwanted porpousing or flightyness at speed , from what ive read the outer ones are def for turns though.
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BJ

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Re: trim tabs and where to put them?
« Reply #3 on: May 04, 2007, 05:41:57 PM »

I would run it first to see how it behaves before adding trim tabs. The boat might not require any tabs.
If your transom is reinforced with say a 3mm ply panel then tabs can be screwed on as a retrofit.
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martno1fan

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Re: trim tabs and where to put them?
« Reply #4 on: May 04, 2007, 07:11:33 PM »

I would run it first to see how it behaves before adding trim tabs. The boat might not require any tabs.
If your transom is reinforced with say a 3mm ply panel then tabs can be screwed on as a retrofit.

hi the boats been running for a while now ,ive had problems with prop walk and flipped once so thought tabs would allow me better trimming to sort out both.the whole boat is plywood i built it all myself from scratch  ;D she runs pretty well just having a few teething problems at the moment.heres the latest video where i think shes running a little wet.needs more tweaking of the tabs ,i think i had too much angle down on them.http://www.youtube.com/watch?v=32Vj4vgFqoA

heres the flip sorry about the noise of the wind the mic cover had blown away lol.
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http://www.youtube.com/watch?v=32Vj4vgFqoA

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