simonfraser
Well-Known Member
Trim tabs trim the boat, according the conditions / speed / amount of fuel carried / etc.
One would just set them as needed ?
One would just set them as needed ?
Trim tab indicators, why ?
- Thread starter simonfraser
- Start date
kashurst
Well-Known Member
I find the indicators a useful reminder to say "b@ll@ocks!" very loudly when, on returning to the boat and turning on the ignition, to discover that I have left the boat with the trim tabs fully down for 4 months and they will now be jammed solid with sealife and weed.
now did I remember to raise the tabs back in March ???????
now did I remember to raise the tabs back in March ???????
Last edited:
vas
Well-Known Member
for me (when I manage to get them working...) will be to know they are indeed working and moving as either the one or the other is stuck solid or moves only half the travel, or or...
usually end up in the water checking with son on the control moving them, it's a fun 15mins father and son bonding session every week on board
V.
usually end up in the water checking with son on the control moving them, it's a fun 15mins father and son bonding session every week on board
V.
Mr Googler
Well-Known Member
I’ve just ordered Mente Marine controller.
Worlds most expensive trim tab indicators
Hoping the auto function works well too
I adjust quite a bit as people move about etc....
Worlds most expensive trim tab indicators
Hoping the auto function works well too
I adjust quite a bit as people move about etc....
Seastoke
Well-Known Member
I’ve just ordered Mente Marine controller.
Worlds most expensive trim tab indicators
Hoping the auto function works well too
I adjust quite a bit as people move about etc....
sounds like a diet is needed
BruceK
Well-Known Member
While you're up there nick it so I can trial test it :encouragement:
CLB
Well-Known Member
one would, but it helps if one knows where they are before fiddling.
BruceK
Well-Known Member
Seriously though Farsco, let us know how good it is as we are very solid in the water until we move past 26 knts upon which I begin to notice people moving about. I'm also keen to hear how it handles wind shift w.r.t. changing boat direction. I spend a good few moments adjusting trim on the dogleg into Conwy Bay against the prevailing SWers and wave direction we get here.
Mr Googler
Well-Known Member
will do Bruce
Seastoke
Well-Known Member
you tabs will require stronger tywraps
BruceK
Well-Known Member
I'm adding some resistance to my boat so you dont have to burn your engines out trying to keep up.
Mr Googler
Well-Known Member
Installed today, super easy. The only new wire required is 12v-. Dropped into the old Bennett switch hole which is handy.
Self calibrated and tabs move to full range and indicators certainly seem correct.
Yet to use it in anger but looks great!
Bought it from here. Great service and cheapest I could find.
https://www.thewetworks.co.uk/produ...ude-control-system-automatic-trim-tab-control
Self calibrated and tabs move to full range and indicators certainly seem correct.
Yet to use it in anger but looks great!
Bought it from here. Great service and cheapest I could find.
https://www.thewetworks.co.uk/produ...ude-control-system-automatic-trim-tab-control
AllanG
Well-Known Member
Installed today, super easy. The only new wire required is 12v-. Dropped into the old Bennett switch hole which is handy.
Self calibrated and tabs move to full range and indicators certainly seem correct.
Yet to use it in anger but looks great!
Bought it from here. Great service and cheapest I could find.
https://www.thewetworks.co.uk/produ...ude-control-system-automatic-trim-tab-control
I’ve also been considering this Mente controller as a replacement for my Bennett controller, so I’d be very interested to hear your views when you’ve had a chance to test it in anger.
petem
Well-Known Member
My boat very rarely needs the trim adjusting. As far as I'm concerned, putting them down just adds drag.
MapisM
Well-Known Member
P, do you also keep outdrives in neutral while cruising? Just curious.
petem
Well-Known Member
That's an interesting question. On this boat (and my last Targa) I have always kept the legs trimmed right in (pootling, accelerating and planing), i.e. -4.
My observation, at various planing speeds, is that trimming the drives out reduces speed very slightly (max 1kt) however other owners report that trimming the drives out to say +1 gives them an extra couple of knots.
As you know FL Olesinski hulls have a tendency to ride bows up but the T34 doesn't seem to suffer this affliction too much - see https://www.youtube.com/watch?v=QCtk8vOUj0I. If course we don't know if Nick had any tab on.
I'd be interested to know if anyone has any advice theories, tips?
Incidentally, the boat next to be is a similar length Windy Khamsin and I was surprised to see that it's trim tabs were nearly double the size of mine.
Portofino
Well-Known Member
I always thought with outdrives you do trim the boat via the leg trim alone .
Indeed -4 is what basically used with my previous Porto 35 .
The actual flaps were there to adjust x wind lean and or any spurious side ways balance issues .So often I would drop one flap to achieve a more level ride .
This is a different approach with a shaft drive as the prop shaft angle is permanently fixed .
Ideally ( not many do ) the boat should plane sub 4 degrees without any tab .
Ideally again a holy grail only found on a few the tabs are there for adjusting as an option not a necessity the water line L
Lowering the bow into steep waves to soften the rise as opposed to backing down the throttles
Or in a fast following sea at speed raising the bow to discourage broaching / stuffing it in .
Again maintaining speed .
Realise today the finer nuances of power boat design seakeeping wise have been sacrificed on the alter of Luxo floating apartments, which sells boats .Thus most on here ride about in benign conditions with shed loads of tabs because they have to .
Indeed -4 is what basically used with my previous Porto 35 .
The actual flaps were there to adjust x wind lean and or any spurious side ways balance issues .So often I would drop one flap to achieve a more level ride .
This is a different approach with a shaft drive as the prop shaft angle is permanently fixed .
Ideally ( not many do ) the boat should plane sub 4 degrees without any tab .
Ideally again a holy grail only found on a few the tabs are there for adjusting as an option not a necessity the water line L
Lowering the bow into steep waves to soften the rise as opposed to backing down the throttles
Or in a fast following sea at speed raising the bow to discourage broaching / stuffing it in .
Again maintaining speed .
Realise today the finer nuances of power boat design seakeeping wise have been sacrificed on the alter of Luxo floating apartments, which sells boats .Thus most on here ride about in benign conditions with shed loads of tabs because they have to .
MapisM
Well-Known Member
The tip is simpler than the theory, i.e. test, test, test. Every outdrive boat I tried was different.
Otoh, as far as theory goes, fwiw in high performance world (which I'm referring to just because it's the type of boating where people go nuts for gaining half a knot) they suggest that the outdrive(s) should always run horizontal, which means as many degrees out as is the optimal AoA at which the hull runs.
Corrections (if required) should be done with trim tabs, because their additional drag is more than compensated by the optimal (i.e. horizontal) thrust vector.
That said, even with very fast boats, it's not unusual to reach the max speed with some further trim out vs. the theoretically ideal horizontal position (and no tabs), because that's the setting which makes the boat run as bow high as possible, which when going really fast means a lower wet surface, hence higher speed.
But with more civilized boats, capable of up to 40kts or so, the very first tip is the only relevant one, imho. :encouragement:
julians
Well-Known Member
On my boat (single engine outdrive windy 25), I use the drive trim to lift the bow to either gain a few knots of speed for any given rpm, or to lift the bow in a following sea. The trim tabs are used to level the boat in the roll axis due to wind or uneven loading, but also to push to nose down when I want to go faster/smoother into a head sea.
The trim tabs can get the nose a lot lower than the drive trim on its own can manage.
On the windy 37 (twin out drives), the drive trim seems to make no difference at all to the running attitude of the boat, but the tabs work well to correct for roll or to push the nose down.
On either boat I need the indicators to know roughly how much trim I'm using at any given time so I know how much more trim I have got to play with.
The trim tabs can get the nose a lot lower than the drive trim on its own can manage.
On the windy 37 (twin out drives), the drive trim seems to make no difference at all to the running attitude of the boat, but the tabs work well to correct for roll or to push the nose down.
On either boat I need the indicators to know roughly how much trim I'm using at any given time so I know how much more trim I have got to play with.
D
Deleted User YDKXO
Guest
Exact opposite for me. At any planing speed up to about 25kts, boat speed is optimised by having a degree of tab down. At about 15kts the boat needs full tab and at 20kts about half tab. Above 25kts the boat is fastest without any tab. Having a trim tab indicator allows me to set the optimum tab for my cruising speed immediately without having to experiment every time to find the optimum speed. This is typical of Ferretti hulls
