Designing surf tabs out of auto trim tabs

Here is what I was thinking, please any input on this would be great.
I am trying to make a shopping list for black Friday/ cyber Monday.

Here is my shopping list right now.

(2) Lenco Trim tab Edge mounted 9"Wx12"L Part # 20159-001 Cost $94 each
(2) Lenco Actuator 4-1/4 stroke Part # 15059-001 Cost $210 each
(2) Lenco upper actuator mount Part #15070-001 Cost #18 each
(2) Lenco Lower actuator mount Part # 50015-001d Cost $16 each
(2) Lenco 20' wiring harness Part # 30133-103D Cost $33 each
(1) Lenco Switch Led indicator kit Part #15070-001 Cost $320
(This switch kit has the wrong part number this one is for a 2-1/4 stroke actuator I need the one for a 4-1/4 stroke actuator but the said it is the same cost) (I am trying to get a part number for it now but it may be a special order the local lenco dealer.)

If I ordered today I would be looking at $1062 plus any taxes or shipping if required.


Okay now here is my plan

Install the two trim tabs Like they are designed for but use a longer stroke actuator to use them as Surf tabs.

I was looking at a kit with the standard 2-1/4" stroke actuators but the plates will only go down to about 22 degrees.
with the 4-1/4 stroke actuators it will go down to about 60 degrees. this was verified with cardboard and a tape measure this weekend.

I think I will be good on the controller it has an input on it. So if it does not have 12 volts on it, it automatic raises the plates to the all up position. (I was going to put this in a rocker switch to turn the system off and on with.) It also has led indicators to tell you were the tab is.

This weekend I winterized my boat and a cut out a piece of cardboard for the tabs.
Here is what I came up with.

1. The back of the supra 21v has a 1/2 in surface change where I want to put the tab.
My plan is to use a piece of Trex decking I have left over to shim this level.

2. The lip of the platform will be in the way. and it is going to be tight against the platform.
It should not be a problem cutting 2 or 3 inches of the lower lip off the platform(It is the part that is against the back of the boat no one should be able to see this.). I might have to raise the platform a inch or two.

I'll be following your progress, that's for sure. :-)

Broke down and order all the parts for the trim tab system. I was hoping to save some money but all I save was shipping taxes and just a little more than that.
everything should be in 5 to 7 days. but I still have 3 plus months to get in on the boat for testing.

Everything but the controller has came in for the system. it is suppose to ship on the 28th I am hoping to move the boat from storage to the work shop Friday or Saturday this week. to start the install.

I also have a second guy looking at redoing the vinyl today.

Looking forward to seeing this all come together. Pics pics pics along the way!

Any further work/design done on the trim tab surf system? I know it's winter and you are probably not in a big hurry but this seems like a great project! Thanks for posting!

Any head way on your design? Curious to see how it turns out!

My construction business got in the why the last two weeks had a friends house catch on fire and a New years day mishap with a side x side going through a garage wall at my parents house kept me from working on the boat. no one got hurt just kept me from working on the boat.
I am hoping to start something in the next week. being in Illinois it will be rough to test anything till spring time.

We've been exploring these options hard for close to two years. I think you'll have a very difficult time getting the results you're looking for with standard a standard trim tab; they additional surface area alone just isn't enough to do the job. Look at the Mastercraft Gen I Surf Tabs for an example of this.

I'll be watching to see what your results are though, as we haven't tested them on any Moomba hulls.

I got the boat into my heated shop this weekend.
Got all the parts I need to put the system together.
The one think I was afraid of with the longer stroke actuators the are physical a little to long to fit under the swim platform.
I was already planning on raising my platform up an 1".
So I am going to raise it an inch and I was already planning on using the tab as a baseplate to add different shape plates to. so now I just got to add about 3" of length to the trim tabs so the actuator will mount a little further back on the tab. (we are going to bolt the things together for now to we see how the system works in the water than when we have it the way we want it we will weld it than.)

On thing nice my family owns a scrap yard so we get all kinds of scrap metal in (stainless and aluminum)
also I have a brother that is a boilermaker and is awesome at welding. He has everything for welding stainless and aluminum. To top that off he is on my boat most the summer and loves to surfing.

We are going to play with it tonight so I will try to postsome pics tomorrow.