Trim Tabs and hydrofoils

[cbadmin]

From: LesLampman (Original Message) Sent: 11/13/2002 7:15 AM

On this forum we'll discuss trim tabs and hydrofoils (generally lift devices attached directly to the motor).

There are 3 general types of trim tab systems available on the market; electro-hydraulic, electric and automatic. The most commonly known brands of the electro-hydraulic variety are Bennett, Boat Leveler Insta-trim and Trim Master; Lenco makes the electric models and Nauticus produces gas-strut automatic tabs. The least likely to be used on the C-Dory boats are the Nauticus gas-strut models; they are mostly intended for smaller boat applications like inflatables and dinghies.

Trim tabs are gaining popularity as folks discover their benefits. For many years tabs were viewed just as a way to cover up problems associated with a lousy hull design and while they can do that to some degree these days they're recognized for their ability to enhance the operation of the boat. Think in terms of flaps on an airplane; planes just couldn't do what they do without the extra control (and expansion of the operating envelope) that flaps provide.

Since a lot of the outboards we're using in C-Dory boats now have power trim and tilt (PTT) most folks want to know why they should add tabs. Don't they do the same thing? Well, not really. It is true that PTT does allow us as boat operators to have some control over the running attitude of our boats but PTT is restricted in its efficiency by the limit of travel the trim system has and the speeds at which we ask the PTT system to work. Another issue with using PTT, especially at the extremes of its range, is loss of efficiency. We get the most efficiency (from a performance and MPG standpoint) when the engine is trimmed to provide the most forward thrust; this is generally when the thrust line of the prop is parallel to the surface of the water. When we use the PTT system to adjust the running attitude of the boat we redirect some of our forward thrust to either push the stern up (to lower the bow) or push the stern down (to raise the bow) thereby lowing efficiency. At slower speeds (say in the 12 to 15 knot range) the operating range and effectiveness of the PTT system does not allow us to always get the attitude we want.

Trim tabs operate independently of the PTT system on the main engine. They are much more efficient than the PTT system in adjusting the running attitude of the boat and are effective at much slower speeds. That gives us needed control when speeds fall into the low double digits when slogging through the rough stuff. The other thing they provide that isn't available with the PTT on the engine at all is lateral trim. Many folks feel that if this were the only thing trim tabs did it would be well worth it. It depends on how much a listing boat bugs you but it does have comfort ramifications as well; with the lapstrake hull of the C-Dory there are times when being able to roll the boat slightly will alleviate the slap from the strakes.

Trim tabs are not a free lunch; first is the investment in the system then there is a certain amount of learning to be done and attention to be paid when running. After a bit having the tabs aboard becomes second nature and the tabs are adjusted by the operator almost as an automatic reaction to conditions. It is also another system on the boat to be checked and maintained if necessary. Fortunately, the trim tab system does not require much maintenance.

Les

From: Da_Nag™ Sent: 11/21/2002 3:32 PM
Any comments on trim tab controls? In particular, I'd like some feedback on the pros/cons of the the single joystick style vs. the dual rockers.

Is it strictly a personal preference issue, or are there functional benefits/drawbacks to one or the other?

Bill

From: Mike Sent: 11/21/2002 5:33 PM
Bill -

It is probably whatever a guy first gets used to that works the best. I know the Bennett folks say the rocker switches are best for those unfamiliar with the operation of tabs. That's what came with mine, and I see no reason to change. I mounted the switches in an aluminum box just ahead and to the right of the motor controller. It is a simple movement of my hand to the switches and back. Wired as suggested, it is a natural operation. The four positions of the switch pair correspond to the four corners of the boat. To lower the port bow, you press the port switch down in the front (it actually controls the starboard tab). Takes about two minutes to train your mind, and then it becomes second nature.

You gotta get you some. When you do get Dana G on the Da Nag for any length of time, she won't be able to sit still for all the fun she's having. Why it is that a woman can sit for hours in a car seat without moving, and only minutes in a boat seat, I don't know. The response to the tabs is quick enough to make them worth using for lateral trim even for short periods. Kinda fun, too.

Mike

From: Redƒox Sent: 11/25/2002 9:50 AM

Bill, I can tell you my preference. My Bennett tabs also came with the rocker switch, at first my thought was, I wish it came with the J-stick type, (familiar to me) but after running both styes, I prefer the rocker style much more. The reason is control, it just is easyer to make fine adjustments with the rocker switch. As far as the placement, I prefer the switch on the left side, so I can work the throtle and motor trim at the same time if need be. I have hydraulic steering, so I don't have to hold the wheel when triming with both hands.
I agree with the comments about the tabs becoming second nature, it's true. I have also said in the past but it bears repeting here also... under nice criusing conditions (consistent and not too rough) one can just use the trim tabs and leave the motor in one possition all through the trip, this saves a LOT of wear and tear on the electric trim motor in the motor unit. It's paying for itself in the long run. I have found the outboard motor trim unit to be a very high maintanance thing, the ones I rebuilt, and it looks to me they are all built by a shock company (Showa) needed brush replacement too often! (in my opinion) I had to buy the brush assembly and it wasn't cheap! I rebelled as usual.... hehe, and found some brushes at a local auto electric shop. It looks and seems to me the electric motor on the Bennett unit can take much more use!

Greg

From: Mike Sent: 11/25/2002 4:45 PM
Greg -

That's cool. My first thought was to wish I had the joy stick, too. Only because it sounded like more fun. But it didn't take me long to learn that when they say in the instructions to make tab adjustments in "half-second bursts", they mean it. With the quick touch of the button when up on plane and trimmed close to ideal, the hull reacts in the time it takes to let go of the button. After a few tries, you do it without thinking. I would be messing with that joy stick too much - I just know it.

Remember when I first put those things on and I was wondering what the heck you got me into? They do make the boat handle differently, but it's just a matter of learning and getting used to it. After just a few hours of run time, the negatives were all but forgotten because of the positives. It seems I read somewhere sometime that C-Dory recommends against using tabs on the 22. I wonder why? I am glad you convinced me I need the things!

Mike

From: Redƒox Sent: 11/25/2002 9:27 PM
It's the single best improvment on the C-D Classic of mine other than the 4 stroke main and kicker. The dual piston tabs I have are only a little fast responding at high speeds, (say..above 22 kts) at the lower speeds it takes a few seconds on the buttons to get the bow down. The dual piston ones use the same pump as the single ones, so the responce is twice as long.

From: stevej Sent: 11/27/2002 8:41 AM
Iv'e got the joystick type on Shearwater other than a single point of control I'm not sure it has a lot of advanatages over the rocker switch type. Sounds like the extra bulk of Shearwater makes her a little slower to react (expect we have the same modle tabs) to adjustments.
They are worth the imvestment use em in combo with the fuel flow meter to fine tune the cruise speed and help adjust for load all the time.
Anyone looked at or used an auto adjuster http://www.bennetttrimtabs.com/autotab.htm
$350.00 from West Marine $50.00 rebait from Bennett sounds kool but I wonder how well they work.

steve

From: Moskwass Sent: 12/4/2002 3:43 PM
OK even
you all have convinced me I need trim tabs, so my question is this
what size do I get for a 1983 angler with 90 hp Evinrude & a 15 kicker on a drop down style mount ?
I have a center drain plug and a transducer mounted on the transom.
Roger

From: Mike Sent: 12/4/2002 5:06 PM
Roger -

You will be glad you decided to do this. The trim tabs add a whole bunch of good things when cruising. Guess you already figured out why you need them, so I can quit trying to talk you into it.

The trim tabs I put on the TyBoo are Bennett Sport Tabs, Model M-120. They are each 10" wide and 12" long (hence the 120, as in square inches). Starting here I posted a series of four pictures to show the location and the amount of travel of the tabs. The fourth picture shows the clearance between the fully lowered kicker and the port side tab.

My kicker is a Honda 8, and I did have to add a mounting bracket to get it away from the transom far enough to clear the tab. The bracket I used is rigid, and its mounting board is about 3" back. With your drop down bracket, your motor should be farther away yet, so there should be no problem.

As you can see from the pictures, the tabs are located far enough from center so as to make the transducer mount and the center drain plug non-issues. If you want, I can get you some measurements and a description of the precise mounting location of the tab hinges relative to the hull bottom and sides.

I don't think you'll notice much performance difference from one brand of tab to another. I bought the Bennett brand because I was familiar with the name. I had to drill a 3/4" hole through the transom on each side to run the hydraulic tubing. If you prefer to run the tubing over the top of the transom, you can exchange the stock Bennett actuators for a style that has the ports on the top so no thru-holes are needed. I preferred to have the tubing concealed, and since the holes are hidden by the bracket, I was comfortable with just sealing them up after running the tube.

Any more questions, just shoot them out here.

Mike

From: Mike Sent: 12/4/2002 5:13 PM
Roger -

I added one more photo to show where and how I mounted the hydraulic power unit for the trim tabs.

Mike

From: Redƒox Sent: 12/4/2002 11:48 PM
Roger I went with the 12x12. And later added some thick plastic to extend them out to 16. Love them that way! on the classic one may want to stay large size, due to the workboat use they might get due to there large cockpit area. Are you shure your 83 Classic has a single center drain?

Anybody??

I thought all the Classics had two drains?

I will post some pix of what I had to do to get around that drain issue.
Greg

From: Moskwass Sent: 12/4/2002 11:59 PM
yes greg
the SENSEI has only the single center drain plug.
I am anxcious to get going on my winter projects, but the weather has not turned to winter here yet. I am still working ground and planting wheat.have not had any time to play inside the shop. it will come soon enough. then we will be wishin it was spring time.
lots of projects planned for the SENSEI this winter


From: Sundown Sent: 12/5/2002 5:41 AM
I have an '86 Angler and am also interested in tabs. A picture of my kicker location is here. As you can see, there is no room for a kicker next to the main engine (which now is a Merc 115 which is bigger than the Johnson 70 shown) and the bracket appears to be right over where the trim tab would mount. Has any one with this configuration added trim tabs? I would appreciate any suggestions. Thanks.
Larry

From: LesLampman Sent: 12/5/2002 7:40 AM
Hi,

I have yet to run a boat with a bad set of trim tabs. They all so their job pretty darn well. We could argue the finer points about whether chord (length) or width is more important but it's really splitting hairs as they all work so well. In general, the farther out they are on the hull the more effective they are (they're pretty much all the way out on the CDs), the longer (chord-wise) they are the more they affect trim, the wider they are the more they affect lift (there are lots a caveats).

I tend to choose tabs based on what will fit. On C-Salt (2002 CD22) I chose to use the Boat Leveler InstaTrim tabs because they have a model with an 8" chord (length) and 12" width that allowed me to clear the Honda kicker that was mounted directly on the transom next to the main engine. I'm mounting tabs on a new CD22 right now with twin BF40 Hondas and I'm going with the M-120's Mike used because the 12" wide models won't fit. And so it goes.

Sundown - lower your kicker motor and measure from the transom out to the leading endge of the kicker. If it's more than 8" you're good to go. Also check to see where the "setting pin" is on the kicker (the thing that sets the trim angle); I ended up moving the one on C-Salt's kicker out to the last hole and that gave me the clearance I needed. Also remember you've got a hydraulic ram to mount in the center of the tab that goes to the transom so check above that location to make sure you've got a place to attach it on the boat. I'll try and post some photos in the detail album for this topic.

I've used a lot of Bennett and Boat Leveler products and I'm quite happy with both and would keep either for personal use. I recently had a conversation with the fellow that runs Trim Master trim tab company and it sounded to me like he had some good stuff going and really wanted to work with C-Dory folks. This isn't an endorsement, I haven't worked with his products yet but it'd probably be worth checking out; some C-Dory folks have installed the Trim Master tabs and liked them.

Les

From: Da_Nag™ Sent: 12/5/2002 9:11 AM
Don't mean for this to sound like a Bennett ad, but they are the only folks I've spoken with so far. Some of the following may apply to other manufacturers as well.

RE the 8" clearance - the Bennett 9x12's are actually 8 5/8" on the chord. Could make a difference. Also, the folks at Bennett did mention they would make a custom tab. Didn't inquire as to price, as the 8 5/8" will give me the clearance I need.

Also, you don't need to mount the rams perfectly vertical - they will function fine if they are off-set somewhat to the side. This will make the difference in getting around my kicker bracket. Bennett will also swap the standard rams with shorter versions, if height issues arise - this may come in to play with my swim step.

I'll post pics and document the process as mine get installed - probably within the next couple of months.

Bill

From: Mike Sent: 12/5/2002 6:52 PM
Larry -

I'm not sure, and Les can correct me or qualify my statements if needed, but I don't think there is a real "science" to the size of the tabs. The bigger the tab, obviously, the greater the effect. But the things are just pieces of stainless steel. I would think that if an inch or so was cut off the length for a custom fit, as long as both were similarly modified, they would work just fine. Shoot, Greg added a few inches to his. What I am not sure about is whether they have to be square on the trailing edge, or if a kicker clearance notch would be OK. If I needed mine shortened, I wouldn't bat an eye. Might be sorry, but I would saw then right off.

Just my two cents - or if I'm wrong, it could be two hundred bucks!

Mike

From: Redƒox Sent: 12/6/2002 12:59 PM
Larry, I have the same system and there is no problem with my tabs extending 16 inches out. The kicker when lowered all the way still has 5 inches to go before it would contact the tabs. The angle adjust rod is all the way out on the kicker, other wise it might come close.

http://www.msnusers.com/CBratsTech/trimtabshydrofoildetailpics.msnw?action=ShowPhoto&PhotoID=51

Take a look ^ up there

Greg

From: Redƒox Sent: 12/6/2002 1:17 PM
Mike. I certainly think so, when it comes to modifying the lengths of the tabs. The reason I went to the max on the length of tab..16' was for better more noticeable performance at slow speeds. More critical for the C-D Classics with the totally flat bottom. I can drive the bow into some really serious chop and not slap bottom most the time and maintain a slow on-step cruise to. only drawback is the bow getting steered by the water when it's down into the water like that, one must stay on top of things and tend closely the sreerage. Another nice thing about them being long is how they keep your stern from getting all banged up when drifting or anchoring in shallow rocky places. I extend them all the way when doing these kinds of duties... usually gathering wood.

From: Redƒox Sent: 12/6/2002 1:22 PM
http://www.msnusers.com/CBratsTech/trimtabshydrofoildetailpics.msnw?action=ShowPhoto&PhotoID=47

Take a look up^ there Bill at my swim step cut out. I would think that the shorter rams would have less travel. You don't need to go that route as you can see.

From: Slow -N- Easy Sent: 2/17/2003 8:34 AM
Nice discussion, but what about the C-Dorys with a twin motor application? I know that I have seen 1 on the old site. There was not much discussion about the trim tabs verse the hydrofoil. I have a twins with the SE Sport Hydrofoils, since I installed them I am able to control side to side list from load as well as bow down.

Well I get better performance, handling with trim tabs on this application?
How does the boat react when the tabs are set and a person moves from one side to the other? Do you have to readjust the tabs? or does this not matter with tabs?

I bought the hydrofoils because of cost and experamentation.

Thanks for your insights and knowledge in this matter.

Bill / Slow-N-Easy

From: kenonBlue-C Sent: 2/17/2003 9:01 AM
Slow-N-Easy, there are quit a few folks with twins and tabs and I aim to be one of them before summer is over. I also bought the hydro widgets for my hondas and sure like the added trim ability but, as Les pointed out somewhere umungst the threads here, when you use the engine to trim the the boat you lose effeciency. It sounds like using the tabs I'll be able to trim the boat and cruise a few MPH faster. I would imagine that adjusting for shifting cargo with the tabs would be no different from what we do now with the engines. Besides, I gotta be able to keep up with Tyboo

From: Swanny Sent: 2/17/2003 9:17 PM
I have a 2003 CD25 and replaced the small factory trim tabs with the largest size I could without relocating the hydraulic pistons (Insta-Trim Boat Levelers). Go to the Bennett Trim Tab web site (www.bennetttrimtabs.com) for a good discussion on their use and purpose. The bigger the tabs (surface area) the better. This my 4th boat with trim tabs, they are very nice to have and increase your comfort at slower speeds by keeping the bow down (V or flat hulls). Best not to use them in a following sea, or if you do, very little. Yes, moving loads from one side to the other while underway will need a slight adjustment of the tabs to level the boat. Very quick and easy to use, either with rocker switches or joystick. The boat cuts the chop better too if it is level and not in a bow-up attitude. You can easily adjust for best efficiency by watching your speed with no throttle change. My boat runs best with maybe 1/4 down tabs and engines with very slight down trim (15-18 knots).

Hope this helps,

Steve

From: kenonBlue-C Sent: 7/9/2003 8:43 PM
OK, I'm sold on the trim tab idea. After cruising around the lakes last week on water that was like glass, I started wishing for a little more SPEED. I'm thinking those Doel Fins cost me a few mph and removing them will add a few back. Adding the tabs will gain me a couple more........yup.....figgure I'll get that thing up to 80mph. Outfit in Portland has the Bennets 120s for $ 389.00. When I get done busting my hump painting the house, I thinks the labor bill will come out to.....oh......about.....$389.00. Hope to get them on next week in time for Blakley

From: Mike Sent: 7/9/2003 10:38 PM
You'll be glad you did. That's a good price on the 120's. Those are the same ones I have, and I paid $415 in Astoria.

There should be plenty of room alongside your twin motors for the 10" wide jobs. But, if you can't turn all the way, big deal. Slap one motor in reverse!

You'll get them on in time for Blakely. It's an easy install, and everything you need is in the box. Unless you don't want to drill thru the transom for the tubing. Then you have to mail exchange the actuators for top fitting jobs so you can tube over the transom. But that might look dorky, so just drill the holes. And if you push the drill through too far and poke the fuel tanks, don't worry about it. You won't need that much gas at Blakely, anyhow.

Good deal. M likes the idea?

From: kenonBlue-C Sent: 7/10/2003 6:46 AM
M ? I have a bit over 10 inches between the chine and my depth finder sending unit. If it fritzes out I'll remove it and mount a chunk of wood in that spot, then mount the transducer on the wood in a more benificial location. That way I won't have to be filling and drilling holes to relocate the bugger

From: stevej Sent: 7/10/2003 7:04 AM
BC you'll love those tabs, I use my fuel flow meter to base the trim adjustment on. It reacts mush faster than the GPS giving you instant feedback when you make a change. Just wish the thing would point to something less than 7 to 10 gph. Blakley trip sounds like fun and why not have a new toy to show off.

stevej

From: kenonBlue-C Sent: 7/10/2003 5:59 PM
hummm flow meter....that would be nice to have a pair of those.....ya, I think those tab gadgets will be the cats pajamas....now if I ever get finished painting the house

From: Molly Brown Sent: 7/15/2003 2:01 AM
Hey Les:
Don't suppose tabs would fit on a TomCat? Boat runs fine but just thinking......James

From: kenonBlue-C Sent: 7/15/2003 11:55 AM
The trim tabs are on.... while sitting in the driveway, the tabs reponse time seems to be the same regardless of what engine noises I make can't wait to get them wet

From: Mike Sent: 7/15/2003 1:01 PM
Far out!

From: kenonBlue-C Sent: 7/15/2003 8:50 PM
They ain't to far out, only about 12".
That booster seat thingy I made had a provision for mounting a trim tab control just aft of the engine controls. Conincedince?...I think not

From: kenonBlue-C Sent: 7/26/2003 8:22 AM
I've read all the glowing reports about trim tabs and thought "someday". With the twins and fins I was able to trim the boat laterally with no problem so thought I wouldn't gain a whole bunch, other than a bit more cruising speed,with the tabs. WRONGO, man, being able to auger that bow down into the chop makes a HUGE difference in the ride quality. Not only did I gain a few mph's on the smooth water but on choppy water where I used to grit my teeth and run about 12mph, I now find myself speeding along at about 18mph and not even noticing the bumps. now I know why you guys are so keen on the tabs....I'm a believer

From: Da_Nag™ Sent: 7/26/2003 10:19 AM
I've yet to hear of anyone installing them that didn't rave about the difference in ride. I think Dusty first said it, but I agree with him - if I were starting over, they would be the first thing I installed.

Ken - did you keep your fins on? I was contemplating taking mine off after the tab install, but I like the way the boat handles as is - I'm hesitant to mess with it.

Bill

From: kenonBlue-C Sent: 7/26/2003 11:10 AM
Yes, I removed the fins (anybody need a set) I figgured they wouldn't be serving much of a purpose now that I have the tabs and they where costing me some umph...Dusty is correct, slam those tabs on first thing......I'm such a cheapskate though, had to mess around with the fins
In a cheapskate related vein, I whacked out a 15 square inch hole under forward dinnet seat and stuck a nifty access panel on there that I got at Home Depot for $15. The panels have a spring loaded latch and just pops on and off, they can be found in the pluming department. They're used to cover pluming manifolds.


From: Redƒox Sent: 7/26/2003 12:51 PM
Wow, I could not have said it better myself Ken. I let a couple C-Nuts try out RF this spring and I demonstrated the effects while turning and doing other maneuvers, I also let them try it out for themselves. I'm not sure they liked the attention one has to pay to them while encountering changing conditions, it's sort of like learning to fly the boat rather than just throttle it around. In the long run though all you need to do is try endure a long trip heading into chop and then a fella would kill to have them on his C-Dory.... much more pleasant ride, better fuel economy, faster speeds.
I know I said this before but it bears repeating here. I took off my hydrofoil because in a trailing sea I would get too much lift from it along with my 12x16 tabs. Another reason for the removal was it did slow me down a couple mph on top. Last but not least, I think they (especially on a single engine) put the lift in the center while underway, making the boat feel like it was tipsy.
The thing I miss about the 'foil is the anticavitation was far better with it than with out it. What I'm going to is make one out of 1/8 stainless (very thin and sturdy) and make it streamlined and small in comparison with the ones on the market now.
greg


From: Molly Brown Sent: 7/27/2003 12:09 PM
Hey Dory People!
Still would like to know if there's room for tabs on the TomCat?t The way I measure it it looks iffy....James


From: Redƒox Sent: 7/28/2003 1:36 AM
Holycow, I never once considered the possibility of them on a Tom Cat, I see what you are saying! I'll be watching this one.
(curious greg)


From: Mike Sent: 7/29/2003 8:44 AM
James -

I wish I could help you, but I just don't know. The one you're waiting on to reeply is Les, but he is up to his eyeballs in work. Shoot, I put him a good three hours behind last week. He does check in here when he gets a chance, but he hasn't had a chance for a while.

You should be able to get a pretty good idea by cutting a piece of cardboard the size of the tab you're considering and taping it in place where it goes. Then you can turn the motors and see what the clearance is.

As for the perforance questions and the effect the tabs might have on the multihulled beast, you'll need someone more learned than me to guide you. Who knows, maybe you'll be the precedent setter.

Sorry I can't be of more help.

Mike


From: LesLampman Sent: 8/1/2003 7:15 AM
Hi James (Molly Brown),

I finally got caught up enough to start checking in here once in a while.

At this point I don't see how trim tabs could be fitted to a TomCat. Even if a set could be made to fit on the transoms they would be way too close to the props and would trash the water flow to them for sure.

On C-Salt we installed the Honda SST hydrofoils on our twin Honda 90's. We've now run that set up 80-odd hours and the results seem to be good; we have much more trim authority. Steve on Two Dawgs also put a set on his TomCat but so far his results are more mixed. I don't know if this is due to the mounting height of the engine, boat weight, props or just what. We're running Honda Logo 17" stainless props and they're absolutely excellent and give us no trouble with the SST's.

I suspect that weight distrubution may play quite a role in the performance of these hulls; C-Salt does not carry much weight forward (there's nothing stowed under the forward berth) and she's pretty light as not much gear has been brought aboard.

I have had 6 adults aboard and she still perfoms well, although I can definitely tell the difference. Having a thousand pounds of gear aboard would really make it a different boat and my experience so far is that the lighter the better.

Les


From: Skip Hood Sent: 10/21/2003 7:06 PM
Hi folks -

A set of trim tabs for my 22' Cruiser should be arriving any day now. One of the install decisions that may or may not be well covered in the instructions is where the optimum location for the control switches might be. They certainly won't say what works best on a C-Dory helm station.

I've never run a boat equipped with these, but have a vague notion I might be wanting to jockey the throttle, engine trim, and tab trim around the same time to make everything right for what's going on a a given moment. A simple example from past experience is that I usually trim the engine down at the same time I'm throttling down to adjust for running off-plane. If that kind of thing is an issue with tabs, too, it could be a mistake to mount the tab controls where it's a long reach from the throttle/shift lever, or where you'd have to change hands to keep one on the wheel.

Or....maybe I'm making too much of this and any place you can reach with one hand or another is just fine. I'm eyeing that nice round spot to the left of the wheel where a second engine gauge would go if needed.

What do y'all think? In particular, does anyone who's used trim tabs on their C-Dory awhile wish they'd mounted the switches someplace else?

Many thanks,
Skip




From: Mike Sent: 10/21/2003 7:31 PM
Skip -

When I put the tabs on my 22 Cruiser, the toggle switches they gave me got mounted in an aluminum electrical box right in front of the throttle/shift controller on the box the seat is on. They work great for me. It is a simple movement from the throttle lever to the switches, and after a short while I could do it without thinking.

The new (used) boat I just got has a joystick type tab switch that is mounted to the left of the steering wheel. Even though I haven't really used it yet, I suspect I will be moving it to the previously described position so it can be operated with the same hand that works the throttle. It seems a natural fit to me.

Unless you have a hankering for the joystick type switch, you will probably be better off with the supplied (for free) toggles. I have mine sitting flat (parallel to the seat) and it is so simple. The four switch positions represent the four corners of the boat. If I want the port bow to go down, I push the switch located closest to the port bow. If I want the starboard bow to go up (the same as the starboard stern going down), I push the switch closest to the starboard stern. So simple. In just a few minutes it becomes natural. The joystick will take some getting used to, I think.

You're gonna love 'em!

Mike

[TWO-DAWGS]

Hello: Just move to this new site. Les mentioned that I had installed the SST fins on my TOMCAT about the middle of summer. My initial reaction was mixed. I lost a little top speed, and I had a slow learning curve on how to get my trim adjusted. It is counter-intuitive if you are used to trim tabs. If I want to lower the left front of the boat to get better side to side trim, for example, I raise the left motor trim or lower the right motor trim. Weird, but it works fine. I can now hit a 3/4 sea with a perfectly level boat no matter the number of passengers who want to sit at the port-side table. Les suggested I give it a little time to get used to it, and he was right - as usual. I have used tabs on other boats, deep V hulls, and have always recommended them to my friends. I think I would still rather have tabs on the TOMCAT if it were feasible, but the SST fins work fine. The also look cool, being color coordinated. My wife would say it is the only think I own that is color coordinated.

[TyBoo]

I just read over the stuff that was moved to this forum from the old CBTech site. Lots of good info here.

Now, back to my piddly little problem. I found the trim tabs on the TyBoo25 to be woefully undersized at 12 x 8. Running with them fully down would smooth out the ride and lower the bow enough to see over, but there was nothing left for lateral adjustment.

A little bit ago, I jerked the tab plates off of the boat and looked them over. I think it would be real easy to attach a 4" extension piece of stainless steel onto the length. Then, by moving the stop pin for the kicker up one hole, I would be able to have 12 x 12 tabs without adding any more holes to the boat or my wallet. The system that is on the boat is Bennett hydraulic, and looking over their stuff I find that they run some big tabs with the single actuator like I have. So, I reckon there shouldn't be any problem shoving the extra surface down into the water. The system can take the added hydaulic pressure working against the rams from the larger plates OK, because the relief valve that is opened every time the actuators are fully extended and the switch is held on will keep anything from rupturing. Right?

Somewhere on here, or in one of the other TT discussions, Les said that wider tabs will create more lift, and longer tabs will provide more "trim". (That Les is pretty sharp on some things, ain't he?) I take that to mean the longer tabs will tip the boat side-to-side more. Right? That's what I want to accomplish, and Kay would like that too. Then I won't be telling her to sit still so much.

So, unless somebody talks me out of it (I do listen to reason, mot of the time), That's my plan.

[CAVU]

Tyboo,
I don't really have any experience with trim tabs, but I can't resist a comment or question about your statement on length vs width. It seems logical to me that the only relevant factor would be the increase in square inches (area) of the tab? Adding length or width shouln't make any difference in the amount of lift if the areas are equal? I would be interested in the reasoning why one would be more effective than the other.

[TyBoo]

Good question, and it will be interesting to hear Les talk a little on it. I'm guessing the length has to do with leverage; the further out the tab is from the back of the boat, the more that corner (and hence, the opposite front corner) of the hull will react to the forces applied by the water it is gouging. Width, on the other hand, will apply the force across a greater part of the beam to provide lift. If you had a couple tabs in the water that were 4 x 36, you would span nearly the entire width of the boat and the force of the water would lift the stern for sure, but you wouldn't get much action side-to-side by altering the position or depth into the water of the indiviual tabs. If you put that same 144 square inches into a 12 x 12 shape on each side, you would not get near the total amount of stern lift, but it could be varied a great deal more between the sides. It all has to do with that physics stuff I avoided in high school, I'm afraid.

[TyBoo]

Disregard the previous rambling about how to save a couple hundred bucks. I took the tabs to work today to clean them up and add extensions, but found they were corroded clear through in spots. Then I started to make replacements out of a better grade of stainless, but decided against that, too. I ordered a set of Lenco 12 x 12 electrics.

[B~C]

ouch, that's a bummer, I guess this means you'll have less beer buying money in your pocket for the Cathalemet meeting of the Columbia river contigent of the C-Brat auxilliary squadron floatilla.

[TyBoo]

Yeah, but just think about what I could make with the old hydraulic power unit!

Them Lencos are about a hundred bucks les than the Bennett hydraulic tab set. They operate with a ball screw and motor sealed inside each actuator. Ball screws are strong and reliable, and I never was too crazy about pumping hydraulic fluid through the transom. These should be good. I saw somewhere that Les had plans to put a set of Lencos on something he was rigging, and that says a lot to me, right there.

Oh well - I'm back on the 12 hour days this week. I will, however, be looking to swipe a pivoting bow roller off of somebody's boat at Cathlamet. Didn't you finally end up getting one for the front of the Blue~C, B~C?

[Da Nag]

[Alyssa Jean]

I was just at EQ last week-end getting an anchor windlass installed and I think I saw a pair of Lencos on a red 22. In fact there where two red 22's there. Anyone we know?

[Cheers]

Tyboo wrote:

[B~C]

Mike, you could work that power unit into the sliding Safeco Field roof project......I'll bet a small hydraulic motor would't be to hard to find.
Word of warning on the pivoting bow roller, I can go from snoring to roaring and popped out the bow hatch in 0 flat....I lernt that in Washougal.

[Coastie Dory]

Hi all,

One nice thing about the Lenco tabs is there is no pump taking up space on the transom! I want to install them on one of our stock boats if it does not sell too soon. I have seen a large number of new boats in the midwest going to the Lenco system and so far heard no complaints. I do not have any feedback on how they do in salt. Leaks are not a good thing, but outboard trim motors will tolerate river water for a while before they quit. Salt water should wipe out a motor real fast. I figure leaky actuators should cause problems for the salt water guys first and I would like to hear about any problems if they occur.

I will post results and pictures when I get a Lenco system on one of the Dorys.

Best wishes, Randy.

[Chuck S]

I'm looking seriously at trim tabs for my 16 Cruiser, mainly to handle lateral trim.

With the 2" thick hull on these boats is there any problem installing the tab brackets and having the thru bolts clear the hull botom?

Anyone do this on a 16 Cruiser? Bennett M80s look like the best fit at present along with the joystick control, but if the Lenco full electrics work well they'll be much less hassle I imagine. The cylinders just appear to be a bit long for a 16 fooer.

-- Chuck

[Da Nag]

Chuck,

If you are talking about the tabs themselves, you don't through-bolt them - they are screwed on. Just make sure the holes are pre-drilled the correct size and depth; too big, the screw won't hold, too small, you'll snap off the screw or crack the gelcoat. Don't ask me how I know...

Apply plenty of 5200, both in the pre-drilled hole, as well as on the screw. I put a small ring of it around each screw hole as well (between the hull and the trim tab hinge.) Once you tighten down the screws, you'll have enough time to clean up the excess the squirts out.

Depending on the manufacturer you go with, the only through-hull hole is in the top bracket of the ram; on TrimMaster tabs, this is where the hydraulic tube shoots through, on Lenco's, I think this is where the electrical connection goes through. Either way, this hole is above the water line on 19/22's, and I assume it would be on the 16 as well. Still, it should still be sealed properly.

The info below is from one of the combined posts transferred over from the old site - reposting here for clarity, and I updated the picture links to work. I highly recommend using the template method described below - makes installation a lot easier.