10 meter trim tab question?

[yorklyn]

After sandblasting and painting my origional tabs (boat leveler) I'm now thinking of replacing them due to the many areas where corosion was pretty bad. The existing tabs were 24x9 which I extended to 24x12. According to the bennett site a 10 meter should have 36x9 or 42x9 tabs. the 24x9 tabs were way too small. it made a difference when I extended them 3 inches so I'm sure it wouldnt hurt to go bigger. I measured and can fit 42x9 with good placement of the rams on the transom if i run the tabs accross the rudder pocket. Whats are you 10 meter guys running? Are you happy with your set-up? Thanks

[tsawyer]

Mine are stock and not big enough. I wish they had more effect than they do.

When you figure it out let us know.

[koviak]

Replaced mine with 24x12 bennets with the drop down fins and have been happy with them. Going slightly larger should be fine as I run tabs fully down at cruise with my set up. It seems as hull design makes it difficult to keep running angle down to efficent levels. Give a shout out to TABMAN on this and other sites for some more info.

[Big D]

Interceptors is another technology that is gaining speed as a viable option now. They've been around for a while but starting to get more popular with the recreation crowd. Offshore charter fishing boats are starting to spread the word also. They're great for fishing as they won't get torn off when in reverse at higher than manoeuvring speeds like tabs do. One of the popular concerns with interceptors is drag but reports don't seem to be critical in that regard, in fact depending on the study you read, they are found to be more efficient and have less drag than the tradditional tab. They perform much better at higher speeds than tabs do in terms of efficiency and response times however I did come across one study that contradicted this, stating that for the same degree of deployment, tabs provided more lift. All other papers seem to contradict this though. My only caution would be about being selective in the design chosen. Volvo for example incorporates external electromagnetic actuators to lower the plates and we all know the concern with having electrical components susceptible to water emersion. There are makes however that are actuated from inside the vessel through the transom. It's hard to beat the true tested, trouble free, simple hydraulic design of the Bennett design but there are other options when the application's design limits selection. There is a lot more info on the web about interceptors now....worth the read as an additional option in your bag of bolts. If nothing else, the read helps to understand the lifting dynamics and how they act on your vessel. Here is just one article and a Humphree ad video.
http://www.powerandmotoryacht.com/refit ... terceptors
http://www.youtube.com/watch?v=NhVeDfUF_O0

[RWS]

here's some good info

http://www.trojanboats.net/wforum/viewt ... gle#p33656


RWS

[Wes]

I replaced the original 24x9 trim tabs with Bennett 30x12 with dual actuators. Bennett recommended this setup. Ours in an aftcabin and I wanted more lift in the stern. They seem to be doing a good job.

[alexander38]

I'll put my vote in for the 42's, I'll be testing my new ones in a little over a week. I'll report back on them.

[yorklyn]

Sorry for the delayed response. Been short on time between working on the boat and kids baseball and softball. Those intercepters are nice but way out of my price range! I think the acuator will be in a better position with the 42 inch rather than the 36 inch. I'm leaning towards the 42x9 or 42x12 but am concerned about spanning over the rudder pocket. if I dont want to go over the rudder pocket I'm stuck with 30x12 as the largest and bennett recommends at least 36. Anyone think the 4-5 inches of "floating " non attached tab will cause an issue? Heres a pic that shows the pockets.

[RWS]

consider that the drop fins will multiply the effectiveness of a smaller tab.

they will also NOT add to the wetted surface, although that is really insignificant here.

Worked for me.

However, my engines are farther forward with the express

RWS

[yorklyn]

Thanks Harris,
Are you running the 30 inch tabs? if so are they 9 or 12 inch? I think I may give bennett tabs a call and get their opinion.

[RWS]

factory = 9 x 24

replaced with 12 x 24 with drop fins

This is a direct replacement and uses the same actuatators.

The drop fins make it work as a larger tab.

I went over all the details with the Bennett people at the 2003 Ft lauderdale boat show.

I brought all my detailed data and they ran the numbers to determine what was needed.

Why overkill if it is not necessary.

(who me? overkill? no never)

RWS

[gardnersf]

I replaced mine with 30x12 last year. I bought the kits but used the boat leveler actuators as rerouting the hydraulic line would be a tremendous chore on one side. They worked well but I did shear the Non metalic pins on both actuators. I replaced with stainless steel pins and all has been well. 30x12 was the biggest I could get with the rudder pockets.

[yorklyn]

I Think the 30x12 will be the safest option for me. I may look into the "drop fins" like Harris has.