La Frette tab'd

Erin · 12 April 2012, 20:28

Just thought I'd post a little summary and a few pictures from fitting trim tabs to La Frette. Hopefully it may be of use to others wondering how hard it is to do.

A quick spin on Gotchiguy's 'Into the Red' last year convinced me that I'd benefit from raising the stern slightly when cutting through the chop. (If you read between the lines I'm conceding that the egg whisk is a bit lardy - but don't tell Gotchi

). I'd also read Chris' posts about fitting tabs to Time Bandit which were also positive so took the plunge and bought a set.

Although Bennett hydraulic tabs are the most recognised brand I really didn't want the complexity, nor did I have the space for mounting the pump unit. This narrowed it down to Lenco or Lectrotabs. Not much to choose between them, and although the Lenco's have nice waterproof cabling connectors, I opted for the Lectrotabs because the control switch looked better and ASAP supplies had all the parts in stock.

Fitting was quite simple.
photo 1 shows the marked out locations.
photo 2 shows the antifoul scraped back to the gelcoat so the Sika will stick
photo 3 shows the holes pre-drilled. I countersuk a recess to allow a bit of space for the Sika to provide a good waterproof bead.
photo 4 shows the tabs fitted
photo 5 shows them antifouled and wires routed through the transom into the transom boxes. (Glad I specced underdeck conduits on both sides)

Erin · 12 April 2012, 20:31

Final couple of photos showing finished transom and control switch.

The switch panel is customisable to control the operation of the tabs. You can swap which tabs works on which switch and also their speed. They also self retract once I turn the engine off and do a quick alignment check each time the engine is powered up.

bliksem · 12 April 2012, 20:47

Hi Erin

do these trim tabs really offer a real differende on a rib (I see these also a lot on Scorpions and they are supposed to have one of the best hulls available?) The Osprey Vipermax is also a very capble hull so I wonder where is your advantage? Do you have increased top speed? lower fuel consumption? or just a better (quicker ride) in choppy conditions when raising the stern and how much quicker is it then?

Erin · 12 April 2012, 21:14

I haven't launched the boat yet, so can only tell of my experience driving 'Into the Red' last year. I'm not expecting any more speed, I may get lucky and achieve a very slight fuel saving, but my primary reason was to level the hull a bit when the conditions allow to get the bow to cut through the chop and waves better and give a smoother ride. I certainly noticed a difference when driving Into the Red and was amazed at how much effect they had when fully down. They really made the nose dig in and slowed the boat right down.

GJ0KYZ · 12 April 2012, 21:38

That's a really good looking job Keith, nice one. Bliksem: I think the advantage will be the improved trim. I tried a prop last year that dug the stern in and produced a noticeably bumpier ride.

Channel Ribs · 13 April 2012, 06:22

Great pics and a lovely neat job.

La Frette is a tad stern heavy, so in this case the tabs will help to bring the nose down when encountering surface water.

Most RIBs are able to achieve the full range of trim by the outboard alone, so they are not a common sight.

I am prepared to bet a pint that the comfortable cruising speed, in conditions other than calm, will improve.

Erin · 13 April 2012, 07:48

Quote:

Originally Posted by Channel Ribs

I am prepared to bet a pint that the comfortable cruising speed, in conditions other than calm, will improve.

I'm not falling for that one cos I think you're right

Channel Ribs · 13 April 2012, 08:21

Quote:

Originally Posted by Erin

I'm not falling for that one cos I think you're right

What was your average speed in a F3?

Erin · 13 April 2012, 08:49

Are we talking wind with tide or against? Could be anything between say high 20's and low 30's I 'spose.

martini · 13 April 2012, 10:48

Don't forget, got a couple of props here to try out as well.

Sent from my portable speaking device using Rib.net

Erin · 13 April 2012, 13:07

Quote:

Originally Posted by martini

Don't forget, got a couple of props here to try out as well.

Looking forward to it.

Chris · 14 April 2012, 05:41

Quote:

Originally Posted by Channel Ribs

Most RIBs are able to achieve the full range of trim by the outboard alone, so they are not a common sight.

IMO most ribs would benefit from tabs. My 6.5 had an e-tec 150 on the back so was not stern heavy at all, but in the rough being able to really pin down the nose made a very noticeable difference.

Also when you have a heavy load onboard having the tabs is very handy!

Quote:

Originally Posted by Channel Ribs

I am prepared to bet a pint that the comfortable cruising speed, in conditions other than calm, will improve

At least 5 knots more !

Nice job Erin ! You mat want to get those tabs stiffened though...

One final word of caution.. If you find yourself out in really shit conditions and are using the tabs just don't forget they are down if you turn round to run with the waves or it could all end in tears !

Erin · 14 April 2012, 08:34

Quote:

Originally Posted by Chris

Nice job Erin ! You mat want to get those tabs stiffened though...

I did consider that, but wondered whether this need for stiffening was really genuine or just a form of ribnet Chinese whispers. I suspect someone some time ago though it'd be a good idea and this then became gospel. Not disimilar in my view to having two batteries on a single engine leisure rib - a bit overkill. Time will tell tho'.

Do you actually know anyone who has buckled their tabs?

Chris · 14 April 2012, 09:03

Roy Bishop was the Originator of this and yes he did it because he had bent some in the past.

I guess a lot comes down to how you use them and the speed you use them at.

Chris · 14 April 2012, 09:05

.....

gotchiguy · 14 April 2012, 12:04

Nice job

Interesting that you went for the "Lectra" both our's and Chris' are Lenco so time will tell how you get on! Agreed the switch looks nicer!

Re strengthening, it does just provide a little piece of mind knowing how strong they are. I have even found them useful for climbing up into the boat (not regularly, just when necessary) and it makes the transom access route much easier I think. With these physically large sized engines, the cowling extends out so far either side that climbing up the skeg is hard I find.

Top speed will not increase I don't think. I know Channel Ribs is an opponent of tabs on ribs but we find that they are very very useful. The conclusion of our trials last year resulted in us deciding the engine is slightly too high to be perfect for us but nothing proper trimming can't solve as demonstrated by CR!

I think the most telling thing was on the way back from MtStM last year, we were able to comfortably run at least 5 knots faster than La Frette which I don't think on its own the extra half metre could achieve nor the extra crew of LF. She was certainly bouncing around a lot more in the head on 1.5ft? chop, which for us was not too bad at all.

So when do we get our consultation fees?

Trevor G · 14 April 2012, 12:55

Quote:

Originally Posted by gotchiguy

I think the most telling thing was on the way back from MtStM last year, we were able to comfortably run at least 5 knots faster than La Frette which I don't think on its own the extra half metre could achieve nor the extra crew of LF. She was certainly bouncing around a lot more in the head on 1.5ft? chop, which for us was not too bad at all.

You'd better watch it Gotchi -
I think Mrs E may have something to say about that next time she sees you.

Erin · 14 April 2012, 13:11

Quote:

Originally Posted by gotchiguy

So when do we get our consultation fees?

Stupid Boy! I only pay for worthwhile advice....

Quote:

Originally Posted by Trevor G

You'd better watch it Gotchi -
I think Mrs E may have something to say about that next time she sees you.

She's lookng for her hockey stick as we speak, ready to belt him one.

gotchiguy · 14 April 2012, 13:26

Quote:

Originally Posted by Erin

She's lookng for her hockey stick as we speak, ready to belt him one.

Please remind her that it was a comment on quantity rather than quality....

Erin · 14 April 2012, 14:04

Quote:

Originally Posted by gotchiguy

Please remind her that it was a comment on quantity rather than quality....

I'm not sure that actually helps your case