help for trim tabs

[tbhobe]

I have a 170 Aquasport with trim tabs but shortly after I bought my boat the trim tab pump died I looked on ebay but the cost for a new pump was to high I found that there is a kit with preloaded shocks that replace the old ram and now my boat rides and get on a plane better than when the trim tabs worked  I hope you all might try this  no more switch to try to set right no more pump and rams that fail over time   good luck
                                                     tbhobe

[Capt. Bob]

Excellent.  

Are these called "Smart Tabs"?
 I believe there is a member or two that have used these before.

Personally I like my hydraulic tabs. I've been running mine for 15 years so there's not much guesswork in where they need to be set for most sea conditions. A trim indication device helps us old guys remember where to set 'em for the boat performance we wish to achieve.

Good luck and post a pic of your work.

[seabob4]

Smart Tabs are a very good (and inexpensive) alternative to the more commonplace hydraulic (Bennett, Boat Leveler) or electric (Lenco) tabs, especially on smaller boats like the 170.  While they are not nearly as versatile as the former, their biggest attributes are quicker planing times and, typically a higher top end speed.  Speed increases can usually be gained by going with with different diameter and pitched props, as the benefit of the tabs in helping the boat plane allows you to run a prop that will benefit the top end with out sacrificing hole shot times...

But they are not a substitute for fully adjustable trim tabs...

[MarshMarlowe196]

 for Seabob-

I need some trim tabs as my boat has developed a list while on plane.  I don't know if this is possible because of my stern wells.  Is there an option for me?

[seabob4]

 for Seabob-

I need some trim tabs as my boat has developed a list while on plane.  I don't know if this is possible because of my stern wells.  Is there an option for me?

...and I betcha she sits nice and level at rest.

The problem obviously is your stern livewells.  Although I love them, they are in the way of any type of tab you could mount should a list develop.  Now a possible suggestion, depending on the severity of the list, would be to add some weight to one side or the other to offset the imbalance.  But then, she'll probably have a list at rest.  One thing I have seen done is add a "hook" to the hull trailing edge on the side that needs to come up.  Hooks work like tabs in that they provide lift, they are most often used to correct a porpoising condition that are a tendency of certain hulls.  The newer Proline 26 Express is a perfect example.  It shares the same exact hull as the 26 SS (center console), yet because of weight imbalances and hydro-dynamics, it had a list when planing.  The mold was modified to incorporate a hook, and when an SS hull was laid up, an insert was placed in the mold to delete the hook.

Talk to your Dad about hooks...

[fitz73222]

Try running the boat with the transom livewell lids open and see if one is over filling or underfilling. I believe the previous owner on my 22-2 had this problem and corrected it with adding or filling a couple of holes until she leveled out. You havent coincidentilly changed the engine height or changed to a different prop recently? It is strange that the list has recently developed and nothing with the livewells has been altered. Which way does she list, to port or starboard? Does the list change as speed changes?

[MarshMarlowe196]

Try running the boat with the transom livewell lids open and see if one is over filling or underfilling. I believe the previous owner on my 22-2 had this problem and corrected it with adding or filling a couple of holes until she leveled out. You havent coincidentilly changed the engine height or changed to a different prop recently? It is strange that the list has recently developed and nothing with the livewells has been altered. Which way does she list, to port or starboard? Does the list change as speed changes?

I just added the wells not long ago, and they're still really neat to watch so I watch them all the time    .  They're both working fine.  I plumbed them in a way that overfilling or underfilling is not possible.  The holes are right at the waterline and equal in height on either well; as soon as the boat's in the water, the wells are full, and while on plane, they have no way of draining below the "at rest" waterline.

I had a slight list before I added the wells (prop spin?), but the list is worse now with the wells.  I think the problem is the way I rebuilt my transom.  Here's a pic:



I added a layer of wood to the outside of the transom, and the wells are overlapping the wood now.  When I installed the wells, I had to fill in the gap between the wells and the original transom.  The wells themselves have a slight downward pitch that's different from the hull (even with an original transom), so they naturally bring the bow down.  I think one of the wells is angled down slightly more than the other because of my new transom.

The boat lists to port, so I'm thinking if I add a pad (or a "hook" - thanks SB), that might correct the list... It's just hard to get something like that just right.  That's why I'd rather have tabs.

From looking at the picture, would it not be practical to add tabs between the wells and the motor?  Or would this not work?

Sorry to hijack this thread.  These things happen  

[seabob4]

Jess,
The optimum placement of tabs has always been as far outboard that you could locate them, but inboard of the chines.  Now, that doesn't mean they won't work further inboard, they just won't have the same effectiveness as the outboard location.  

I am betting (and that's a bet, mind you) that if you snug the tabs up against the inboard side of the boxes, you will have success with correcting that list.  But, and there is always a "but", that's a high price to pay if they don't.  So you might want to try this.  Get a piece of 1/8" aluminum, have it brake bent to provide a mounting flange, have it bent to about 12-14 degrees, and screw it into your transom, level with the hull.  A "fixed" tab, so to speak.  The tab should be 9"W X 4"D.  It seems like you are going to be drilling holes in your transom anyway, this is a cheap experiment.  The additional lift on the port side may cure your issues.

Note I said "may"...

[fitz73222]

I would try tweaking the livewell(s). Make some temporary precise wood wedges at varying degrees and screw them to the  rear edge of the port livewell until the list corrects itself. Someone handy with a table saw can make them for you in 1-2 degree increments. It probably wont take more than a 1/4 inch of wedge to correct this depending on the severity of the list. I would much rather tweak the livewell geometry than drill holes in my transom. Once you get the right wedge glass it in place and a little paint or gelcoat and done.

[seabob4]

I would try tweaking the livewell(s). Make some temporary precise wood wedges at varying degrees and screw them to the  rear edge of the port livewell until the list corrects itself. Someone handy with a table saw can make them for you in 1-2 degree increments. It probably wont take more than a 1/4 inch of wedge to correct this depending on the severity of the list. I would much rather tweak the livewell geometry than drill holes in my transom. Once you get the right wedge glass it in place and a little paint or gelcoat and done.

That would work as well.

[Capt. Bob]

That's why I'd rather have tabs.

From looking at the picture, would it not be practical to add tabs between the wells and the motor?  Or would this not work?

Sorry to hijack this thread.  These things happen  

It's listed under help for trim tabs and discussing alternatives as well as any type of tab would seem to fit so sorry, no hijack.

Back to your post, if you haven't already, try this link. Interesting product but any hydraulic tab system is costly.
http://www.bennetttrimtabs.com/catalog. ... &catHome=1

Good Luck






l

[MarshMarlowe196]

I would try tweaking the livewell(s). Make some temporary precise wood wedges at varying degrees and screw them to the  rear edge of the port livewell until the list corrects itself. Someone handy with a table saw can make them for you in 1-2 degree increments. It probably wont take more than a 1/4 inch of wedge to correct this depending on the severity of the list. I would much rather tweak the livewell geometry than drill holes in my transom. Once you get the right wedge glass it in place and a little paint or gelcoat and done.

I will try this- Seems like it will work.  I don't expect to dial it in perfectly, but running with such a list sure is annoying.  Thanks Fitz  

[fitz73222]

I would make the wedges about about 3-4" wide and run the them the width of the livewell from the inner edge to the edge of the chine step. They will need to be knife edged at the leading edge and 1/4-3/8 thick at the trailing edge to get started. Hold them in place with 4 #8 oval head screws. You may have to 5200 the leading edge to keep it from being ripped off during trials. In order to measure progress, take a small level and tape it the floor on the port side and see if the running attitude changes as you add more wedge until she levels up. If you think that 3/8 wedge is not enough to start with maybe be go with 1/2-5/8 thick at the trailing edge and sand it back until she levels out. This is seat of your pants engineering but I think the concept is feasible. Can't wait to hear the results. Good luck

[GoneFission]

Here's my $0.02 - I think your baitwells are acting as trim tabs.  They look to be about in line with the hull bottom - I believe when Aquasport put those on the original boats, they were raised up a bit so they did not affect the boat on plane.  Your mounting could actually be helping you get to plane quicker...  

So you might want to try putting your hook on the baitwell.  I would try a piece of 1/2" thick starboard glued to the bottom of the baitwell...

[fitz73222]

The baitwells on my 22-2 are original factory installation and have a 5-10 degree downward rake towards the rear which in fact act as trim tabs. They are mounted flush with bottom at the transom and tilt down towards the rear. I think the intent of the rake was to facilitate good water flow at high speed combined with a slight angular drill pattern to help scoop up water when running. I have watched these wells at high speed and it looks like a washing machine in there. Hearty baits like pinfish, mullet, shrimp and pigfish seem to do fine. Pogys get beat up pretty bad.