Trim Tab size on Offshore?

DennisG01

GreatGrady Captain
Joined
Sep 1, 2013
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Location
Allentown, PA & Friendship, ME
Model
Offshore
For anyone that has an Offshore model (or similar), how big are your trim tabs? Mine are 24" wide. Don't get me wrong, I'm fine with that - just curious as it seems like that's pretty big for a 24' boat. I have no idea if these are original or not.
 
When I had my 87 Offshore It had 9x12 Bennetts. It was a twin engine with a Grady drive. I took the tabs off and made 12x12 tabs. Wish I had taken pics . Those 12x12's would bury the nose, but more importantly I could hold plane down to around 15 knots instead of 18 knots with the 9x12's.
 
It's funny, I know the tabs work (including auto retract), but during the sea trial, I didn't even use them. The darn boat popped up onto plane so fast I didn't even worry about playing with them. I gotta think that 24" of span (typically more effective than chord) is going to take VERY little input to adjust the attitude of the boat. And certainly shouldn't have ANY problem keeping the bow down in a choppy sea.
 
Just outa curiosity, how many cylinders on each tab?
 
Just one. But the chord is 9" (maybe 6" -- I'll have to check) so I don't "think" it necessary to have two rams? Bennett's a good company and I'd be surprised if they packaged it this way. BUT, I suppose there's always the possibility that a PO made this change on his own. Hmmmm... 'ya got me thinking. Maybe I'll give Bennett a call and see what their thoughts are.
 
Not quite sure by about what you are calling the "chord" . It just seems like a long plane (24") to be supported in the middle with one hydraulic cylinder. I have no doubt as to whether or not the cylinder will push it. I'm sure it will. How thick are your tabs? Most are about 1/8" thick.
It seems to me that the tabs would bend or flex at the outermost ends due to the force applied when they are down. Once bent I doubt they would return to their original shape. :hmm
When I did my 12x12's I welded apiece of stainless angle iron 1/1/2" x 1 1/2" x 9" 's long across the tabs and used the vertical leg side ( rib) of it to mount the cylinder to. This way I used the original cylinders and original mounting location. This was done in regards to where the cyinder mounted to the tab. hope this made sense......
 
RAINMAKER said:
Not quite sure by about what you are calling the "chord" . It just seems like a long plane (24") to be supported in the middle with one hydraulic cylinder. I have no doubt as to whether or not the cylinder will push it. I'm sure it will. How thick are your tabs? Most are about 1/8" thick.
It seems to me that the tabs would bend or flex at the outermost ends due to the force applied when they are down. Once bent I doubt they would return to their original shape. :hmm
When I did my 12x12's I welded apiece of stainless angle iron 1/1/2" x 1 1/2" x 9" 's long across the tabs and used the vertical leg side ( rib) of it to mount the cylinder to. This way I used the original cylinders and original mounting location. This was done in regards to where the cyinder mounted to the tab. hope this made sense......

"Chord" is the front to back measurement, while "plane" is the left to right.

Good point about "bending". The aft edge of the tab is turned up, sort of like a built-in angle iron. Yes - I do understand what you mean about adding the angle iron and the spot you added it to - my Sundancer has OEM tabs that are just as you describe.

I suppose...... whether or not these tabs are OEM or not.... it's obvious they've been on there a long time and there are no signs of bending at this point. I'm probably thinking too much.... :roll:
 
I don't use my tabs either. With the twins she is right up on plane and i just use the trimming of the engines to raise or lower the bow.
 
my tabs measure 12 by 9

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