Brutus

[Diede van AbsParticipant @diedevanabs87670]

Now there, Bob. That last video certainly looks the part! Nice and effortless cruising about without looking slow, and a nice turn of speed and semi-planing (but with the bow still in the water!). THAT's what I had hoped to see the first time around! Lovely.

As for the lack of comments from my side (I read your remark about FD ) I have been on vacation, with only limited time and access to internet.

The motors feeling chunky is indeed due to the magnets, these motors have only few but strong magnets making them good at high revs – but less suitable for scale sailing and maneouvering.

I am not sure I like the big grinning teeth, it is fun surely but not quite my taste. Each to its own, I guess.

You should however cut out your windows and replace them with either glazing or high gloss black sheet stuck behind the window frames. I believe that will make for a better appearance.

May I suggest shopping for detailing ideas at the Von Dutch and Wally speed yachts? I think these boats have a design language that really fits Brutus.

[Bob Abell 2Participant @bobabell2]

This should please our Paul?

Brutus is coming out of the shadows and into the limelight again with a double motor transplant!

Twin brushless motors to be exact

Having checked up……..Happily, they fit nicely!

Bob

[Paul TParticipant @pault84577]

Hi Bob

The model would certainly benefit from the extra power.

Which of the many brushless motors are you fitting as it would be interesting to know the specs.

Paul

[Bob Abell 2Participant @bobabell2]

Hi Paul

The motors are ……Turnigy D3536/6…….1250 KV

The Controllers are…….QUIK Series…….Car-45 A

Input 5v-12v

Batteries 7.2v……4600m Ah

Bob

[Paul TParticipant @pault84577]

Hello Captain Bob

I don't know much about these brushless thingies …..do these go just as fast in reverse?

Paul

[mike farrellParticipant @mikefarrell21522]

Hi Paul It will not go as fast in reverse as it has a blunt end Michael

[Paul TParticipant @pault84577]

Hi Michael

The blunt end is the worry as there will be a very real risk of the boat submerging if it goes to fast in reverse.

Paul

[Bob Abell 2Participant @bobabell2]

Hello Paul

They go very fast in reverse too

Not to worry, I've taped up the hatch

We could have fitted a bow thruster and then sealed the stern?………Would be a novel feature

Finished the wiring but not fired up yet!

Bob

[Bob Abell 2Participant @bobabell2]

Hello Paul

The motors ran first time and as sweet as a nut!

Will have a test run in Coniston Pool and then a proper run at Etherow

Duckie is available for the obligatory video

Bob

[Bob Abell 2Participant @bobabell2]

Hello Paul

We had a successful sea trials at Etherow this morning

Brutus ran really well………One snag was that the bow wave in choppy water…….Burst over the top deck and into the boat!

Duckie made a short video, which will be posted shortly

A few pictures…………The last two are old pictures that have slipped in by mistake!…….Sorry

[Bob Abell 2Participant @bobabell2]

Hi Paul

This is the spray problem!

Any suggestions?

Bob

[Diede van AbsParticipant @diedevanabs87670]

Hi Bob,

Spray rails would do the trick, but spoil the looks… Maybe if you add a small-ish one on the waterline, so it doesn't stand out too much?

[ashley needhamParticipant @ashleyneedham69188]

The question is, how fast was the craft designed to go? Looks good at slightly slower speeds.

Spray; Paul is the designer and so will have to be the one to advise.

I would say thet the easy fix is to make sure water does not get in the cabin, seal it up or whathaveyoy.

I like to see water crashing over the bows in a bit of rough weather….

Ashley

[Dave MilbournParticipant @davemilbourn48782]

It's a sea-axe. Aren't they supposed to cut through the waves instead of riding over the top – or did I miss something?

DM

[Trevor HollowayParticipant @trevorholloway99134]

One of Pauls first posts on the design : "Brutus has a knife bow and as Dave says it is designed to slice through the water rather than skim over them."

I think it achieves this.

[Bob Abell 2Participant @bobabell2]

Since Brutus is not rising, meeting the waves……It's a Sea Axe alright

Fitting a deflector under the cabin and out the sides, and the front top sealed with tape……It should sail like a Torpedo!

Got a feeling that Paul is not too well at the moment……..Get well soon, Paul

Your comments are well missed!

Bob

[Paul TParticipant @pault84577]

Hello Bob [and all]

Firstly you need to know that this hull as it is a hybrid containing the best of sea axe and planing hull features, all credit has to go to Bob for faithfully following the design on what must have been a bewildering set of drawings.

The bow is intended to slice through the water rather than ride over it but the underwater profile quickly changes from axe to planing.

At speed the hull rides on the water at a rotational point half way down the hull (roughly in line with the front of the superstructure) whilst the bow still cuts through the water.

Photo 1 below shows the boat in its ideal trim position with a very fine and sharply defined bow wave being formed at the waterline level. At high speed the boat should have exactly the same attitude in relation to the water but be riding 15>20mm higher

Photo 2 seems to indicate that the boat is bow heavy however this could be due to the chop so I cant be sure until I see the video. The image also shows an interrupted bow wave (the ripples rear of the mouth) which is due in part to the decals creating a rough hull surface (not evident on photo 1)

This model is essentially an experiment with a new hull shape and was always going to be tricky to trim correctly.

If the bow wave continues to be a problem after making the trim adjustments then it is feasible to increase the width of the foredeck by the addition of a narrow concave section spray rail so that it over-sails beyond the hull and directs the bow wave back down.

Sorry for banging on but some of the features are difficult concepts to explain.

Paul

[Bob Abell 2Participant @bobabell2]

Hello Paul

Thanks for dropping in and your technical comments

The Bows are slightly down……Due to ballast being added to get the stern up a bit

Will fit a top bar to deflect the spray and seal the lid………And go for it!

On calm water, we don`t have a spray problem

The brushless motors are lovely to work with….btw

Video to follow soon

Pleased that some of the forum members have taken an interest

All the best……Bob

[Paul TParticipant @pault84577]

Bob

Without the lead in the bow you shouldn't need to fit any spray deflectors.

Paul

[Bob Abell 2Participant @bobabell2]

Hi Paul

With no ballast, the stern is slightly under by about 5mm……..Hence the ballast

Will have another run shortly, with the deck taped up

Bob

[Paul TParticipant @pault84577]

Captain Bob

Instead of adding ballast try moving the battery packs further forward but don't worry about the stern sitting low as it is designed to be like that.

Paul

[Bob Abell 2Participant @bobabell2]

I could move the batteries forrad, but it's a big job

Will look into it…..Now that the high tech cooling fans have been removed…….It may be possible

Bob

[Diede van AbsParticipant @diedevanabs87670]

If you look closely to Sea-Axe ships – the real deal, that is – you will see they do have tiny spray deflectors at the bows too. I think installing one or two small ones would decrease water on deck.

Having said that, a wave-piercing hull shape is indeed built to slice through the waves rather than riding over it – just look at on board videos of the Earhtrace trimaran (later bought up by Sea Shepherd who ruined it by sailing it under the bows of a Japanese Whaler). In heavy seas it resembles a surface-running sub…

I would not move the batteries much forward, Bob, rather take out some lead from the front. You need to get it more or less level in the water, definately not bows down.

Edited By Diede van Abs on 17/09/2015 16:01:50

[ashley needhamParticipant @ashleyneedham69188]

Yes, lead out will make a big difference I am sure..

I would sooner have a stern low trim rather than a nose heavy one, especially at faster speeds.

Ashley

[Trevor HollowayParticipant @trevorholloway99134]

I think the term is : "adding lightness".

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