Brutus

[Diede van AbsParticipant @diedevanabs87670]

"Also needs to be as designer intended, flat or matt black. Another personal opinion probably not shared with anyone except myself."

I can only agree with your post, Ashley.

Also, I think Brutus should have proper smoke-glass windows rather than these red sprayed-on thingies.

As for Bob's rampage: Sigh…

If a motor doesn't get up to even half of the suspected revs, you are severely over-straining it. Getting the boat up to speed will not help THAT much, and will actually introduce peak loads of MORE than static load. Think corners, and accelerating.

I am still waiting for a new BRUTUS video showing the performance Bob was bragging about. Videos or it didn't happen, Bob!

Edited By Diede van Abs on 17/06/2014 10:37:49

[Paul TParticipant @pault84577]

Hello Captain Bob

A word of caution: Before you go and potentially blow your investment to bits it might be prudent to check with the ESC manufacturer first and explain which ESCs you have and how they are being used.

Mtroniks technical help is 01943 461482.

Paul

[Gareth JonesParticipant @garethjones79649]

Bob,

Just out of curiosity, why did you choose an RV11 speed controller? It is primarily intended for use in remote control cars and has a braking function which can sometime cause odd effects in a model boat.

Gareth

[Bob Abell 2Participant @bobabell2]

Hello Paul and Gareth the Gauges and Diede and Ashley and….Uncle Tom Cobbley lol

Sorry for not replying sooner, but we have been away in the campervan and the WiFi was too slow

The ESC can be found in the Marine section of Howes on line and according the the resident expert, the RV11 is perfect for the job….He was the man who recommended it for the fancy motors

i'm confident that Brutus is on a happy comeback now

Diede, there is no video of Brutus blasting out the water, it was only a water test, but it looked full of potential

Paul, thanks for the info, but I feel sure there is no risk with the ESC……Famous last words?

Bob

[Bob Abell 2Participant @bobabell2]

Hello Paul

It seems a shame to let Brutus fade away into the background?…….It deserves some TLC and another coat of looking at and some eye catching bling adding?

With the chain drive idea, we can get with any size of motor in the hull……. (the propshaft is very low down)

Brushless is the obvious motor choice, but fancy the idea of two pairs of 850's geared together for a bit of oomph!

The main problem encountered from the last debacle, was water getting in through the very short rudder tubes, which have no sealing effect.

I'm thinking of removing the rudders altogether and use tank steering

What do you think, Paul?

Bob

[Paul TParticipant @pault84577]

Bob

It would be a shame to let your Brutus languish without realising its full potential. As you know I am not a fan of adding bling to any model and Brutus was intentionally designed to be bland, almost stealth in appearance but its your model so ultimately its your decision.

You are right in thinking that brushless is the way to go on this boat. The problem with using 4 850s is the extra weight that these motors (and batteries) would add to the model, I suspect that the gain in power would be lost in pushing the extra mass about.

Where did the short tubes come from?

Removing the rudders might not be such a good idea as tank steering such a long and slender hull would be very difficult and sluggish.

Paul

[Bob Abell 2Participant @bobabell2]

Paul

As I was saying, a few days ago, the rudder tubes are so short, water can get in quite easily

It needs a seal of some sort?

Brace yourself for an outrageous suggestion!

Outrageous suggestion…..Remove the rudders and plug up the holes……Fit a kinky rudder at the front!

It would work, in my opinion and would be quite a novelty

It needs your blessing, my son

Bob

[Colin BishopModerator @colinbishop34627]

Thick grease usually helps Bob, not suitable for propshafts but quite OK for rudders. Bow rudders were normally only fitted to paddle steamers and some other older ships to assist in steering when going astern. They were locked when going ahead for safety reasons.

Use a bow rudder when going forward and you are basically tripping the boat up. The results will not be pretty!

Whilst rudders at the stern are often used to catch the propwash and literally heave the stern round, the true rudder action is to unbalance the hydrodynamic shape of the hull which then amplifies the turning force applied to the hull. In a sense it makes the hull slightly banana shaped in terms of water flow so you get different pressures on each side of the hull which causes it to turn in the desired direction. That is why old time sailing ships have such small rudders proportionate to the size of their hulls. The rudder is only there to unbalance the waterflow around the hull. The hull itself does the work.

Also, just think of the force that would be applied to a rudder if you stick it on the bow and then turn it while the vessel is going ahead, it would be torn off instantly!

And while the situation is slightly different, how many model boats have you seen that are fully controllable when going astern when using the rudder(s)? Not many, I'll bet!

Colin

Edited By Colin Bishop, Website Editor on 16/07/2014 09:44:37

[Bob Abell 2Participant @bobabell2]

Thank you Colin

It was a daft idea anyway

Now thinking of outboard rudders similar to SloMo, but there`s not much meat to bolt onto!

I did think of tank steering?…But the hull is long and thin!

Think an O-Ring seal is probably the best idea

Such is life?

Bob

[Diede van AbsParticipant @diedevanabs87670]

Hi Bob,

My suggestion to the rudder issue would be to glue a washer flush with the underside of the rudder tubes, then a small rubber o-ring and a second washer loose on top (bottom). Then insert your rudders through this all, and lube the rudder tubes with thick grease (I use Teflon grease to good success, water repellant and reasonably thick, obtained from a bicycle webshop). Do mount the rudders with as little play as possible, because the o-ring and washers need a little bit of pressure to work. That all should keep the water out.

Stick to the designed rudders though, no outboards (would spoil the looks) or bow rudder (a recipe for disaster as Colin already pointed out).

Tank steering is a no-go, the props are too close together and the bow area makes for a giant keel, so it will simply keep going pretty much straight forward.

[Paul TParticipant @pault84577]

Bob

Instead of jumping to exotic solutions it might be better to simply solve the problem that you have with the existing rudder gear.

Where did the rudder shafts come from, did you cut down a commercial pair or did you make your own?

What overall length and diameter are the rudder shafts and tubes?

Is there any form of capping or seal arrangement on either the top or bottom of each tube?

Paul

[Bob Abell 2Participant @bobabell2]

Paul

Got your rudder drawing via EMail….ok

Email out of action at the moment and my reply won`t send

I can sort out the seals

Bob

[Bob Abell 2Participant @bobabell2]

Brutus is ready for a serious sail again

I've refitted the MFA700 motors, which really are strange motors

When the shaft is rotated by hand, it feels very lumpy, as though it was an engine being turned over compression?

It rotates in about 20 degree increments, caused by the internal magnets, no doubt?

They have a fierce turn of speed, so I don't think they are faulty

Any comments on this, please?……Just curious

Bob

[Paul TParticipant @pault84577]

Hi Bob

I have the same lumpy effect as hand I turn Thors motors

[CookieOldParticipant @cookieold]

Hi Bob , I have 2 JP 660 and they are just the same i have been informed motors like this draw huge amps when you start them up .

Dave

[Bob Abell 2Participant @bobabell2]

Thanks Dave

My motors are certain not the normal run of the mill!

They should put on a good show at the next sailing!

Wonder where our Flying Dutchman, Diede is these days, he normally has something to say!

Bob

[Amy jane SeptemberParticipant @amyjaneseptember49770]

I'm looking forward to this…. I want to see her/him really go!

[Paul TParticipant @pault84577]

Hi Bob

Will you able to sail the re-fitted Brutus before Haydock?

Paul

[Bob Abell 2Participant @bobabell2]

Hello Paul

Hope to have a sail next week….Including Ellie

Got no time to do the box top paintings, as you requested…..Sorry Paul

Bob

[Bob Abell 2Participant @bobabell2]

Paul

Went sailing with Duckie today, as arranged and had a successful sorte!

For some reason, we`ve still got the very bad water ingress, but it should soon be sorted in the bath today

Would be nice to do a demo at Haydock?

Brutus ran really well and wasn`t even flat out!…..So we`ve got some good potential

Still think the props are too small, but will get some for next outing

Look at the Axe Head created bow wave, in this shot!…..That should please Paul?

Does it need a small amount of ballast up front?

More pictures to follow and another video by Duckie

Bob

[David WooleyParticipant @davidwooley82563]

Hello Bob and Paul congratulations on your successful sea trials , Brutus does cut a fine wake, the bow on shot looks impressive ,

Dave Wooley

[Bob Abell 2Participant @bobabell2]

Thank you, very much, Dave

Hope to see you at Haydock

Bob

[Bob Abell 2Participant @bobabell2]

One of Duckies photos

He`s caught the bow wave quite nicely…..The knife edge has sliced a crystal clear wave

Note lack of water disturbance

Bob

[Colin BishopModerator @colinbishop34627]

Excellent shot! The bow wave in particular is very interesting. Not much water being pushed around which does indeed suggest that the hull is efficient.

Colin

[Bob Abell 2Participant @bobabell2]

Thank you, Colin

Here`s the video of today`s action by Duckie Video Services

**LINK**

Bob

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