Brutus

[Bob Abell 2Participant @bobabell2]

Thank you, Paul……That was as clear as mud!

Yesterday, I was full of woe, because I couldn`t decide where to install the gear………Balance is vital, says Capt P

But today!…..Happy!……Why?………because I had a good idea!

Simple but a life saver!…………….I`ve simply screwed all the bits together…..Instead of glueing them in position

I can now move the stuff about with no aggro

The main modules slide along the inside spine and are simply retained by one screw…..Now they can move up and down the spine to get the balance right

I`ve even screwed the the rudder block in position too……..Just in case

The way is now clear to connect the wiring and…………and………….Launch!………….Oh dear, I need as Aspirin and a sit down!

Bob

[Colin BishopModerator @colinbishop34627]

Bob,

Yes, that is a very good idea. When building my last boat, a smallish Deans kit, I wasn't sure where the centre of gravity (or floatation!) should be so I made up a plasticard tray holding the batteries, RX and speed controller and fitted two pieces of stripwood along the inside of the hull between which the tray was free to slide forward or aft. When the model was near completed I just slid the tray up and down until the trim was right and fixed it into place by screwing a cross member across the strips. I made sure that the tray was watertight to there is a bonus that the gear inside is protected to a large extent from any water that might get into the hull when sailing.

Colin

[Bob Abell 2Participant @bobabell2]

Thank you, Colin

Great minds think alike! Hey?

The idea has given me the confidence to proceed and finish the boat…….Knowing that I haven`t burnt my bridges!

Bob

[Paul TParticipant @pault84577]

Bob

Its a good idea especially for quick tweaks at the lakeside.

Did you have the time at Ellesmere to test float and tow Brutus as you intended to?

I don't think that you will burn your bridges….even though you might sink your boat lol

Paul

[Bob Abell 2Participant @bobabell2]

Hello Paul

Don`t think Ellesmere was the ideal spot for a public airing!

Anything could have happened, but it would have been a great crowd pleaser!

It may be a good idea to fit a central rail down the entire length of all your models, for instant adjustment at the lakeside, as you mention. The rail would need to be higher than the formers, for an uninterrupted run

Bob

[ashley needhamParticipant @ashleyneedham69188]

Bob. I dunno what you are worried about. It will go just fine. I dont forsee that the bow will rise too much unless going v fast but that appears to be the whole point of the design and I like it.

For my money, only the batteries need to be moved about as they are the heaviest things.

Turning performance…may need tweaking, perhaps some rails underneath or turn fins like the hydro boys but again probably not going to be an issue.

Ashley

[Bob Abell 2Participant @bobabell2]

I may be having a Senior moment here, chaps!…..But please bear with me

My apologies, but I have a question, which is so basic, I'm almost embarrassed to ask!

I am in the process of wiring up the system and can't decide on where to put the inline fuse?

Between battery and ESC

Or…………Battery and motor

Or ………..ESC and motor

Or………….It doesn't matter?

I've never given this question any thought before now

I can only think the fuse is required when the prop is snagged and the fuse acts as an on/off switch

The fuse also prevents the system getting maximum battery power……..Because the fuse will blow first

So how do we decide on fuse size?

Suppose we have a system without a fuse and the motor is jammed…..What will happen?

The motor will get hot and eventually burn out or the battery will go flat?

But what about all those tricky bits in the ESC?……They could act as a fuse?

Just thought I'd ask

Bob

[ashley needhamParticipant @ashleyneedham69188]

Bob. Fuse can in theory go anywhere the main battery current runs, put one in the battery lead I would say.Depends if you want to start cutting connectors off to fit a fuse or can incorporate them in the motor leads. It could be a good policy to fit fuses to all your battery leads and then you never need to worry! fitting 1/4" female blade type connectors is easy as the car type blade fuses fit straight in them, easy to retro fit a fuse.

i think the normal advice is to fit a fuse to suit the ESC… 20A esc= 20A fuse. Most ESc have a little lee way so that this should protect it ok.

Easy option, buy an Action fuse board thingy as you have two ESC, straightforward protection.

Ashley

[Bob Abell 2Participant @bobabell2]

Thank you, Ashley

I normally put them near the battery anyway, but this must put the ESC in the firing line?

A chain is as strong as it's weakest link…..So why fit more than one?

I can progress now

Bob

[Amy jane SeptemberParticipant @amyjaneseptember49770]

Good luck Bob, All this electrickery is too much for this bear of small brain!

[ashley needhamParticipant @ashleyneedham69188]

Bob. Assuming you have two ESC, then the large fuse would be to protect the batt, and two others would be for each ESC..

Alternativly a fuse could be in the motor line to blow if the motor jammed , to the value of the ESC rating.

Ashley

[Bob Abell 2Participant @bobabell2]

Thank you, Ashley

I'll see what I've got in the junk box

Is there any sense in making our own fuses?……It's only a bit of thin wire between two connectors?…..Or, to be posh………….A household fuse?…………….I might be pulling your leg

Bob

[ashley needhamParticipant @ashleyneedham69188]

Fitting the female blade type connectors and car type blade fuses is easy and cheap. More to the point, if anything blows , they are easy to replace and fault at the pond side and so on. get some from a £1 shop.

I am treating your last post with suspicion and don`t forget you are on my "never speak to this person again" list for the last leg pulling.

Ashley

[Bob Abell 2Participant @bobabell2]

Thank you, Ashley………..I`m not pulling your leg, this time

Here`s a work in progress picture of the latest development

It looks chaotic, but it`s not really, it`s just that I`m making very heavy weather of it at the moment

The fans work nicely, that`s one job out of the way and the radio stuff is installed

Only need to wire up the motors and ESC`s now, but it seems like one giant step for mankind at the moment

Cautious Bob

[Paul TParticipant @pault84577]

Hi Bob

Looking very complicated but what is the big SLA for and how heavy is it?

Paul

[Bob Abell 2Participant @bobabell2]

Hello Paul

The battery is for the fans and weighs 1.5 lb

It`s not that big, it`s…….. 5.25" x 2.25" x 1.25"

Bob

[Paul TParticipant @pault84577]

Hello Captain Cautious

The extra mass might have an impact on the handling but we wont know until you get Brutus wet.

Paul

[ashley needhamParticipant @ashleyneedham69188]

Bob. Do you need such a whopping battery for the fans?? they consume a miniscule amount of power.

We had an interesting discussion at the pond regarding the boat (the pond crew are lurking), and are all agreed, but we will see what happens on it try outs!

Ashley

[Bob Abell 2Participant @bobabell2]

Paul and Ashley

The fans are 12v…..My battery is only 6v and driving two fans…….and they are not there for fun………They are doing a constant job of work

What battery are you proposing?

Bob

[Paul TParticipant @pault84577]

Ashley

Please enlighten us as to the fundamentals of your pond side conversation.

I for one am all agog to know what the pond crew think and it would be nice for us all to share in these thoughts before the pond trials.

Come on Ashley its time to stand up and be counted.

Bob

I wouldn't worry about the battery until after the pond trials and if it works out that the battery is to heavy it could be replaced with a small 9v battery.

Paul

 

Edited By Paul T on 09/03/2014 19:32:17

[Bob Abell 2Participant @bobabell2]

Paul

If Brutus had a full length keel, it would increase the turning circle

Since it hasn`t, I`m now thinking it will turn on a sixpence…………And fall over?

Caution once again, is advisable

Bob

[ashley needhamParticipant @ashleyneedham69188]

Paul. The chaps have sworn me to silence, oddly enough, and of course I respect them (well, some of them) and so would not DARE to let on as to our surmisings.

Bob. Not sure you will need so much fan power, I only asked, in the beginning, if there was any through ventilation. The motors, as outrunners ,from what I have seen on our pond, are not likely to get very hot, a bit of air through-put, just to stop heat build-up inside the body I recon will be all that is required .Fans linked to the ESc would of course deliver more air when needed, and less air when going slowly.

You are a headstrong reckless young man and will obviously be driving such a brute at full throttle wherever possible, so perhaps in hindsight a separate 12V battery MAY be required.

A flat bottomed boat is likely to simply skid around the corners, like a car doing do-nuts in a council car park. A keel will surely dig in and flip it over? (see last statement).

Ashley (sitting down)

[Bob Abell 2Participant @bobabell2]

Thank you Ashley for your constructive comments

Fancy asking why I need such a big battery and then finish off with a recco to have an even bigger battery!

And, we don't have a flat bottomed boat…..We have an upturned Banana shape, digging in, fore and aft……That's Paul's inventive genius!

We may end up taking out the fans and battery and we could end up with a hot air balloon!

Paul is thinking, with two stubby wings, it could possibly get airborne!

That's Paul's inventive genius in action again!……It would be like a mirror image of submarine activity?

ie…..Up and down……. as opposed to…..under and up

All good fun…..Bob

Errrr…..What's that?………When are we sailing?………Can't say, I'm sworn to secrecy!

[Paul TParticipant @pault84577]

Come on Ashley

Saying that you are sworn to secrecy is just a cop out and a namby pamby excuse for all of you not having the courage of your combined convictions. As we say up here in't north 'If you've got something to say then stand up and say it'

Paul

[Trevor HollowayParticipant @trevorholloway99134]

I did not swear Ashley to secrecy, my guess would be that performance will depend on the calmness of the water – at dead calm and slow / medium speed slicing should be impressive instead of creating a bow wave. At faster speed rotating and lifting the bow stops the slicing and just gets it on the plane.

My impression of the axe bow design was that it slices through the larger waves keeping an even keel but just rise out of the water lowering drag and increasing the speed with less power.

The Brutus design rotating and getting on the plane seems to be against this understanding.

A canoe sits atop the water with a shallow draft and will cut through the small waves / surface undulations due to a combination of its sharp front end, flat bottom, length, centre of gravity and weight, once the swell increases it still cuts until it climbs up the swell (probably a mathematical factor of its length determines this point).

I am duly impressed at the uniqueness of the design and workmanship of the build and look forward to the videos showing how it handles various water conditions proving or disproving the design, it will be interesting.

I do not know what the others at the Bushey Park pond think.

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