Brutus

[Paul TParticipant @pault84577]

Bob

As far as my limited knowledge goes I don't think that brushless motors create any interference so there shouldn't be any proximity problems for the receiver.

However owing to weight issues I would advise that the receiver is placed in the forward section (bay 3) and the battery pack for the cooling system would be better just forward of the fans themselves fitted low down in bay 4.

This would leave the area between F5 and F6 clear for the main batteries which could be fitted across the width of the model sandwiched between the shafts and ESC shelf. I realise that this makes thing very tight in a small area but you might find it necessary to get the mass of the batteries in that location in order for the model to perform correctly.

Paul

[Bob Abell 2Participant @bobabell2]

Thanks Paul

Will be buying a few of the smaller 7,2v batteries at Ellesmere, to put in the motor compartment this weekend and will pick the brains of the Brushless experts for their comments and advice

I checked at the club last night and it seems that the close proximity of the motors won't upset the ESC's, but I'll put the ESC's in the forward compartment anyway

Hope to meet you this weekend?…..We shall be there, Saturday and Sunday

Bob

[Paul TParticipant @pault84577]

Bob

Did you do the bath test? I am only shooting in the dark regarding battery positions and a float test will provide the answers.

I am hoping to get there on Saturday afternoon but I've put my back out and cant get into the car. I will stoke up on painkillers and do my best.

Paul

[Bob Abell 2Participant @bobabell2]

This what the Doctor ordered!…………..The bath test!

All went well as we expected!

First test……Fully laden with the big batteries and no leaks either

It seemed strange, we normally pile the ballast in on bath tests!

Bob

Water level 50mm up from the bottom corner……….How`s that Paul?

Water level about 4mm over the stern edge

With the smaller batteries and the ESC`s further forward and the fan batteries likewise, we should be laughin`

[Paul TParticipant @pault84577]

Bob

It looks very good and sits nicely on the water, I estimated that the bow should draw about 60 >65mm so your model is almost there.

Paul

[ashley needhamParticipant @ashleyneedham69188]

Bob. My experience with unusual models leads me to rely nothing about bath testing and I would wait for motion tests before even considering where to put the batteries permanently.

PS You need a bigger bath…

. Ashley

[Paul TParticipant @pault84577]

Ashley

I am somewhat downhearted by your comments as I have spent many hours designing Brutus and getting the hull balance just right.

I don't just throw these things together.

[ashley needhamParticipant @ashleyneedham69188]

Paul. My apols. Did not mean to suggest that you had not considered the dynamic aspects. I am not used to people fully designing boats in all their particulars using the tools like wot you do.

I will collect some birch twigs and beat myself for even considering that this might not be the case (not that I was suggesting this in the first instance)

Ashley

[Paul TParticipant @pault84577]

Got you

[ashley needhamParticipant @ashleyneedham69188]

Its no good I shall have to add you to my list of people to hate forever and ever.

It has Bob on it as he was similarly as cruel.

There is room for more, especially in the matter of h#######d.

Ashley (returning next doors birch sticks to the green bin)

[mike farrellParticipant @mikefarrell21522]

Thanks Bob for the info will use as a starter. As for esp next to motors I used them in our R.C racing cars and never had problems with close proximity of either but had some small glitches when near to receivers .Added ferrite rings to cure the problem

Enjoying the build ,well done both.Michael

[Bob Abell 2Participant @bobabell2]

Thanks Mike

That`s nice to know and will remember the ferrite ring trick too

Bob

Ashley

When you`ve stopped larking about……….Some time ago you mentioned the three wires from the ESC and having to swap them about?

Well, I`ve got the same problem……Three blue wires from the ESC to three wires on the motor….red…yellow…black

Don`t like the Trial and Error method……..Any ideas?

Bob

[ashley needhamParticipant @ashleyneedham69188]

Bob. I dont think it matters which wires you connect up, so just connect any wire to any other wire. In any event there are three unmarked blue ones from the ESC so you have no choice.

However if the motor revolves the wrong way to which you want, you simply reverse ANY TWO wires!.

Ashley

[Bob Abell 2Participant @bobabell2]

Thank you, Ashley

When I`ve connected all these wires together……What is the next step?

Looking at the instructions, there seems to be a lot of setting up involved, with plenty of alternatives

Is there anything I should be aware of, before I start pressing buttons?

I think this is the reason why Paul and Dave M and me too…..Have shied away from the brushless option!

Bob

[ashley needhamParticipant @ashleyneedham69188]

Bob. I think the ESc will be set to plug`n`play BUT it will be set for Lipo batts likely, and so have a low voltage cutoff setting possibly unsuitable for Nimh batts.

The best and easiest way to sort this is get a PROGRAM CARD for the ESC. You simply plug the esc into this card, power it up and be able very easily to set a few things like reverse, voltage cutoff and so on. You probably will not have to alter a lot. They are not that expensive, and the options on it will be set out easy to see and to pick out..

Doing the programming of the ESc on the transmitter by twitching sticks and listening to ESC tones is confusing and tricky ….

Ashley

[Bob Abell 2Participant @bobabell2]

Thanks Ashley…..The plot thickens!

Luckily, we`re off to the show tomorrow and I hope the Brushless gear supplier will have a stall there

There must be others too

Bob

[curlyParticipant @curly]

Hi Bob

If the motors and ESC you bought from Vintage Models, they are set up for 7.2 volts, and don't need to be set up. If the rotation needs to be reversed just swap any two wires I hope this helps.

All the best at the show this weekend

Curly

[Bob Abell 2Participant @bobabell2]

Many thanks, Curly

That's nice to know and you make it sound so simple!

Bob

[Bob Abell 2Participant @bobabell2]

Paul

Looking at your pictures of the high speed fire boat at Ellesmere Port, going through it's paces, has got me thinking!

The fire boat looks light at the front and is almost leaping out of the water!

Brutus will be even more so, but we don't want to do any leaping!….We hope to chop through the waves!……Almost like a Resurgam!

So why have we got the light nose up effect?….I would have thought the reverse is the way to go?

No doubt there's a perfectly logical reason coming up!

Bob

[Paul TParticipant @pault84577]

So why have we got the light nose up effect?….I would have thought the reverse is the way to go?

Sorry Bob but can you be a little more specific.

Paul

[Bob Abell 2Participant @bobabell2]

Now, Paul……..I think you are winding me up?……You know what I'm getting at!

Brutus is very bulbous at the front and quite light, which means it will run up and down the waves?

If we had some weight up front, we will surely plough through?

You take it from there!……Brace herself, chaps, I think Paul is about to go ballistic!

Bob

[Paul TParticipant @pault84577]

Bob

Its a perfectly understandable question especially give the unusual design and rather than smother you in techno babble I will simply say do you recall our conversation at Ellesmere Port where I compared Brutus to a canoe

Just like a canoe Brutus has a large underwater surface area and as such floats high in the water and just like a canoe its 'bobbing' action is limited by the hull length.

Also like a canoe most of the weight in Brutus is concentrated within a small area which allows the hull to rise and fall around this mass, adding weight at the front will make it bow heavy and actually increase the propensity of the model to 'bob'.

However all of this is theoretical until the model gets into the water.

I hope this helps

Paul

[Colin BishopModerator @colinbishop34627]

Some interesting thoughts there Paul but surely you could reduce the pitching effect if it is possible to concentrate the weights at the ends or at least spread them along the length of the hull – easier said than done I know and you wouldn't put the weights at the extremities on a full size ship but you can of course get away with it on a model.

Colin

[Bob Abell 2Participant @bobabell2]

Thank you Paul

If it`s any consolation……….Should the model fail to live up to expectations……….. I won`t be upset whatsoever, so don`t you worry about it

Never mind the time and expense, we`ve had great fun over the last few months and that`s all that matters

My thoughts are, that without a keel and lacking weight up front, the boat will sheigh away from the waves, but this can easily be corrected……If not, then it`s the Pearly Gates with no regrets

At the moment, progress is very slow, because the way ahead is not clear cut and Ellesmere is behind us

I`ve tidied up the rudder mech, fitted the main batteries, fitted the fan battery

The wiring needs to be neat and tidy……..Then the fireworks will start!

I still have high hopes for success

Bob

[Paul TParticipant @pault84577]

Bob

Look at the canoe on the right

The same hydrodynamic principals that apply to this hull also apply to Brutus, the canoe doesn't have a keel and it glides over the water rather than plough through it. The difference with Brutus is the extended bow but the science remains the same.

Brutus will almost fly in a straight line and tight turns will be an adventure.

Paul

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