Carbon Fibre Trim Tabs
 

Hi all,
In my efforts to save as much weight as possible during our boats refit i decided to manufacture some carbon fibre trim tabs, the hinge mechanism has been a bit of a challenge as the fibres wrap completely round and back along the tab, the cylinder mounting and reinforcement will be bonded to the top face, the weight will be around one third of the comparable kiekhaefer.

Peter

thats some impressive work!

pimpin'

Wow!!!

Suweetness !

Bad-a$$!

Pretty sweet! what type of layup and post cure? I see you have a uni on the surface are the inner piles alternating? Very nice work.

Thanks guys,
I did quite a bit of testing comparing different carbon fibre layups with ally and steel cut to exactly the same size, the final layup is a 6 layer laminate.. 3 layers of 800gram quadraxial carbon and 3 layers of 600 gram triaxial carbon interlaced.. as we wanted to concentrate the major strength along the length of the tab, with a lesser amounts of fibres in the lamination doing some 45 and 90 degree to add the needed strength across the tabs width. The resin is a high grade polyester, the mould is two piece with bleed holes in the top when the two halves of the mould are clamped together the excess resin exits via the holes.

All The Best
Peter

Brits must give their children weave and epoxy instead of legos. Nice work!

how is the rigidity compared to a set of K planes? I realize that they dont need to be perfectly rigid, in fact thinking about a little flex built in makes sense, just wondering.

Great looking tabs!

Those are sweet!

I will have to say you have the best first 34 posts of all time.
Keep us updated on all of your cool projects!

Impressive work and attention to detail as always.

If you are going through that much to cut weight down on the tabs......... What have you did with the rest of the boat?

It must be cool!

Really appreciate the interest in our project... The plan with the tabs is to make them fairly rigid to the ram anchor point and then allow a little flex from there to the end, the last nine inches curve up slightly in an effort to reduce drag.

Peter

Thanks Wildman,
What started out as a relatively straight forward pull the engines out for a rebuild.. has turned into a bit of a marathon, it soon became obvious there was a huge amount of weight to be saved by changing the construction so all the internal structure has been removed including the transom and has been replaced with high density foam for transom longitudinals and engine mounting pads, all bonded together with epoxies and kevlar, total weight saving is going to be in the region of 1000lbs. This along with the power upgrade should increase the speed to more than 75mph with a fuel burn of approximately 160 litres per hour at max speed.

Peter

Carbon Fibre Trim Tabs
 

Hi All,
I have now cut the hinge notches into the transom mounting plates these will be temporarily fitted to the transom so i can determine the position of the hydraulic cylinder and the tab reinforcement. Cylinders will be mounted almost vertically under the swim platform.

Peter

Very cool project! Keep us posted.

Are those trim pumps lighter than stock, they look smaller

Looks good. Would like to see how they hold up though....

Hi RBT,
We are agents for Parker Hydraulics in the UK and are able to specify exactly what we require. We choose permanent magnet motors and operate them via a polarity changover switch which is spark free.The mercury trim pumps have two seperate motors one for up and one for down which makes them both less powerful and heavier, a pair of our units mounted on a carbon fibre plate are only just over half the weight of a pair of merc units.

Peter

???

Hi Tony,
To clarify there are two sets of windings in the merc motors and only one set of windings in the ones i use.

Peter

I saw that you were testing the samples on what looked like a hydraulic press, what were the numbers for the various materials before failure or excessive deflection? Nice work, maybe you should start building boats.

Those trim pump packages are beautiful, do you sell them or have you considered selling sets to replace Merc's?

Awesome work,
Rick

Tabs
 

Will you make some to sell? If so how much$?

Hi pstorti,
Prior to making the test hinge we made up some 5mm thick flat sheet which i cut into rectangles along with exactly the same size high grade aluminium and mild steel then did quite a number of tests with my hydraulic press, the carbon fibre came out extremely well particulary the bend test, where the steel and aluminium with 3/4 tonne load applied bent and did not recover, the carbon flexed and recovered repeatedly and did not start to delaminate till over 1 tonne was applied pretty impressive for a piece of carbon only 5mm thick and 70mm wide..... the steel weighed 10 ounces, the alloy was 4.75 ounces and the carbon 1.75 ounces so the strength to weight ratio is even more impressive.

Peter

As always GREAT work Peter!!

Jon

Thanks Rick, Jeff A & Jon,
We have already supplied a number of trim pump conversions, we stock two sizes one suitable for bravo's and small tabs the other more suited to NXT No6 and indy drives and large twin ram tabs we also manufacture stainless steel adaptors so that you can use standard 7/16th's jic fittings which makes it much easier to custom build hoses than the merc flare. It is also my intention to market the tabs once they have been prototyped on my own boats, we are still in Key West at the moment enjoying the sunshine back to England friday .....

Peter

Peter ,

Sorry we missed you we were in Orlando for a few days. then Anna Maria Island,..still 5 to 6 hours from Key West. Enjoy the weather we left in the 80's it was 25F here this morning,.........Yikes!

Jon

Do you know approximate weight differences between stock and your style Bravo pump? Are the trim speeds comparable?

Hi Ziemer,
The trim pumps are around 4lbs per unit lighter, the no load speed is about the same, as the pressure increases because the motors have more torque the flow doesn't drop of as much as the standard bravo unit.

Peter

Hi All,
The reinforcement is now bonded to the tab and the final shaping is complete, just need the top weave applying and lacquering then they will be ready for installation.

Peter

Very nice - I take you make body panels for race cars out of CF as well.

Finally got round to fitting the tabs they are 7" longer than the kiekhaefer 380's and one third of the weight and because the cylinder has a much better mechanical advantage adjustment it is much smoother and more accurate.

https://www.facebook.com/PeterUnwin53

Thanks for the information

Like this quote of yours

What about the carbin fibers lifespan. I read the F1 teams put their carbon fiber stuff thru flex tests to see how many flex cycles it can endure before having a failure?

Excellent workmanship... kudos...rm