Prototype build of ELLIE

[lnvisiblemanParticipant @lnvisibleman]

Bob

That's the advantage of LiPos, they deliver a lot more current and are wired accordingly. Just make sure that they are rated to suit your requirements.

Mike

[mike farrellParticipant @mikefarrell21522]

Hi Bob ,Reference your over heating wires I can only assume the battery will have heated as well. If so I can compare the problem with my days flying my helicopter. After about 5 minutes the battery and wires would get very hot ,that prevented me flying the batteries to their full potential about 8 minutes. If I may suggest try a smaller prop and see if you get a longer run time. Michael

[Bob Abell 2Participant @bobabell2]

Sorry about the posting confusion, chaps

We`ve got Ellie and Brutus posts slightly confused….But not to worry, hey?

This is the Ellie thread and this is the Ellie video!…..

**LINK**

We are more than pleased with Ellie`s performance!

Bob

[Andy CParticipant @andyc56856]

Hi Bob

Both boats go really well. Not sure Ellie should be on the plane. Don't normally see that kind of thing on the broads. Is it just me or does Brutus need more speed. Might be better once you have the wiring sorted, but she seemed a bit on the gentle side.

Great videos though. just goes to show what a few bits of wood in the right hands can end up looking like. My cap is well and truly doffed good sir.

Andy

[Andy CParticipant @andyc56856]

Sorry. A great design also helps. Well done Paul. Another cap doffing session.

Andy

[Paul TParticipant @pault84577]

Hi Andy

Is it just me or does Brutus need more speed. Might be better once you have the wiring sorted, but she seemed a bit on the gentle side.

The model is intended to look 'gentle' even when at full speed as the boat is designed to remain level and on an even keel at all speeds. The only give away to speed is the higher bow wave and the secondary bow wave that appears half way down the boats length, If you watch the video you will hear Bob pointing out the bow wave and for a short period you can see both waves.

Due to its underwater design the boats speed is deceptive and whilst the boat is capable of higher speeds the apparent 'gentleness' remains the same. 

Paul

Edited By Paul T on 11/06/2014 08:14:40

[Bob Abell 2Participant @bobabell2]

That`s quite right, Paul

Brutus had some quite good dashes at a good speed at times, but the skimpy wiring became the weak link in the chain and slowed him down dramatically………We can`t call Brutus a "she" can we?

I could tell, he was living on borrowed time!

All good fun though

Bob

[Diede van AbsParticipant @diedevanabs87670]

I strongly suggest adding a spray rail along the chine of Ellie, that will cut down the spray significantly (at least it did on my Tamar pocket lifeboat).

She does run nicely, though, I am very curious how she will react with spray rails, and then flat-out.

Re the Brutus performance: I think it needs a very small spray rail the first few inches of the bow, juuuuust above the waterline, to keep the bow wave in check (just like the Damen FCS vessels have), and it definately needs MORE POWER. It should at least create a nice white wash behind the boat so you can see that there are two props hammering the boat about. It is called "Brutus" for something, right? It should live up to its name, IMHO.

[Bob Abell 2Participant @bobabell2]

Thank you, Diede

I think I like to see plenty of spray!……..So I`ll not change that yet, but many thanks for showing interest in the venture!

As for more power……..I could easily fit one Brushless motor and one Brushed motor to see it`s potential!……Just out of interest……But can`t get it done for Sunday……I need a few new Futaba battery plugs etc on chunky wire

All in good time

Bob

[Paul TParticipant @pault84577]

Hello Diede

Thanks for your comments, I have tried to answer your questions as factually as possible without being over technical

Firstly the Ellie boat was one of three different superstructure designs on a common hull. The Ellie version of the three designs was drawn specifically without spray rails as being a single engine boat this version was intended as a plodding cabin cruiser, the other two versions of the design have twin and triple motor setups respectively and both of these hulls are detailed with spray rails.

Secondly the Brutus boat was never intended to have a spray rail as one of the original concepts was to create a deep and knife sharp bow wave without the white water that is common with high speed boats.

Re Greater speed, as explained before speed is deceptive with this boat especially when viewed from the front as the hulls attitude to the water line doesn't change even at high speed.

Regarding your desire to see foaming white water at the stern I'm sorry to say that the hull is designed to minimise prop wash as one of the main precepts of the design was to create minimum water disturbance.

The boat was called Brutus because of its brutal, minimal, uncompromising stealth design and its ability to move fast without all the white water fuss.

Paul

[Diede van AbsParticipant @diedevanabs87670]

Paul,

I understand what you are saying, I only think the speed is not as deceptive as you say. You can easily compare it to that smaller boat that is also plodding along in the movie, and I think this boat should simply go faster. Both the name and appearance scream out for that. In one of your first posts, you had drawings of the boat on top speed, on the plane and with the bow just skimming the water, and this is simply far from even being close to planing. I miss the effortless-looking speed you are referring to. This hull can do much better than this without looking out of place.
I also was not referring to the aggressive speedboat-like, high-spray, white wash from the back, nor the big rolling wave you tend to see on full-scale speedboats. I was referring to the low-in-the-water, white vortex wash that runs straight in the path the boat just took, that just shows this boat is not to be messed about with.

As for the spray rails; the Damen FCS vessels have them, very small around the knife bow, mainly intended to dampen the vertical motion in a bit of a chop, but they also keep the bow wave from washing over the deck. It still makes for a very impressive appearance and performance.

Of course, it ultimately comes down to the builder whether spray rails are being installed or not. I would definately do so, personally.

As for Ellie, I understand and recognize she is grossly overpowered with the brushless motor. Maybe you are right about not adding spray rails to this boat. She might benefit from a small, bows-only, spray rail though, even when only plodding onwards in a slight chop. But with the current set-up, maintaining a realistic speed will demand utmost restraint from the man behind the sticks

I hope to see movies of the two designs WITH sprayrails soon, though, I think the hard chined hull is very inviting to go fast-ish, and the movie of Ellie is proving just that.

Bob,

you need to be careful with one brushed, and one brushless motor in the hull. The difference in power can easily send the boat out of control, I think.

Sorry if my comments offend any of you, I understand it is really easy for me to criticize you from here. We have a saying for that here in the Netherlands: De beste stuurlui staan aan wal (The best helmsmen are on the shore). Which, of course, is particularly true in our case due to the very nature of our hobby I just think both boats don't live up to their full potential, and it would be even more fun sailing them if they would.

Edited By Diede van Abs on 11/06/2014 15:58:51

[Paul TParticipant @pault84577]

Diede

Don't worry about offending either of us as we both welcome and enjoy healthy debate, your comments have as much validity as anything we have to say.

In fact if we didn't get any comments then this thread would be a boring place and neither of us would learn anything and I have to say that having re-read your postings I am now turning new propulsion ideas for Brutus around in my head.

Paul

[Bob Abell 2Participant @bobabell2]

How about two ABELL drives in Brutus?……That would be four motors!

Quite expensive, but would be very impressive…..Even before we switch on!

Just thinking out loud?

Bob

[Paul TParticipant @pault84577]

Drawing Office to Chief Electrician.

Twin ABELL drives sounds very exotic and would be impressive……….just imagine all of those wires glowing red hot as you push 28amps through them, I have some spare inline fuses (6in nails) that you can use.

How about triple ABELL drives?

Use the twin 700s on a new central shaft and put twin 550s on each of the wing shafts………..now that will fly….with a battery life of 4 minutes.

Paul

[Bob Abell 2Participant @bobabell2]

Hello Paul

My brother has just suggested the same idea for Brutus that you have just mentioned

It's an interesting situation and good food for thought

I fancy four chunky motors and two timing belt drives and slightly bigger props

More later

Bob

[Paul TParticipant @pault84577]

Hello Bob

According to the drawings a pair of 50mm dia props will just fit but it would be best to check the fit with some cardboard disks.

Paul

[Bob Abell 2Participant @bobabell2]

Right then, Paul………..What four motors do we need?….Get it right this time…lol

Would look really nice with two multi drives!

On the Brutus video, did you hear Duckie say that we needed some exhaust pipes…..He really mean't silenscers

But what a good idea?

Bob

[Diede van AbsParticipant @diedevanabs87670]

Hi Paul, Bob,

Glad you are not offended by my criticism.

I think twin ABELL drives would be great, but you have to take care they don't weigh down the boat too much. A boat like Brutus benefits from low weight.
Also, as Paul already mentioned, use thick enough wires or they will glow red – which is a bad thing in a wooden hull. A fuse would be a good idea, too. You might want to look into the car-type fuses; the standard spade-type fuses go up to 30 or 40A. That ought to be enough I believe, and if you really need higher amps you could use mini-ANL or strip-type fuses – they go up to 100A.

Maybe a direct-drive, twin-motor setup using two 1000-size high-revving engines would be a plan?

It's a shame you could not get to terms with that stubborn twin brushless setup of yours, as I firmly believe that brushless motors are the way to go for any high- or semi-high performance crafts. In fact, for almost any craft; the choice of kV-values is so wide you can find a suitable motor for almost every boat you can think of.

As for the noise; you might want to try and stuff a bit of noise isolating foam against the sides of Brutus. The stuff with the eggbox-pattern on one side and stickytape on the other side. It might cancel some of the resonance by preventing the hull to act as a guitar, and improve the overall appearance of the boat. It will be a lot more menacing if it is speeding pretty silently (stealthy!) across the lake.

It will not cancel all the rattle of the brushed motors unfortunately, but it might help a bit…?

Edited By Diede van Abs on 12/06/2014 09:20:49

[Dave MilbournParticipant @davemilbourn48782]

Sorry, guys, but could I ask you to post stuff about Brutus under the Brutus thread and restrict this one to Ellie? I for one am getting totally confused by it – and that generally precedes me switching off to all of it.
Ref connectors, you should be using at least 14AWG silicon-covered cable and Deans type connectors. The plastic Tamiya connectors are good only up to about 15A.

Suit yourself – you usually do.

Dave M

[Bob Abell 2Participant @bobabell2]

Thank you Diede

No offence taken whatsoever, by your blunt but very true observations….lol

We welcome all manner of comments, especially constructive comments, such as yours!

Making bold improvements to an existing model is better than building anew!

Due to the limited space below the prop shaft, after removing the smallish Brushless motors, the motor base material is a bit too thin for the new Brushed motors and the commercially made motor couplings are not too concentric, thus causing excessive vibration

With the new idea of the double ABELL drives, we will have more space for solid bases

See my post in the Brutus thread for latest info on the newly ordered wiring and blade type fuses

Thanks once again for your interest

A photo of the ABELL drive for the readers who may have missed our earlier posts……..

Two of these would be the Beez Kneeezz!

Bob

[lnvisiblemanParticipant @lnvisibleman]

Paul

This is probably a stupid question but here goes anyway !!

Can the drawings be produced in PDF on sheets sized 500mm x 300mm ?

I am of a mind to have all the frames and cabin sides cut by laser and that is the size that they use.

Unfortunately I do not have the software to alter you existing drawings. Not that I would have a clue how to do it !

Mike

[Bob Abell 2Participant @bobabell2]

Mike,

I would have thought that the Laser cutter could work with the software file and wouldn't need a drawing?

But what do I know?

Bob

[Paul TParticipant @pault84577]

Bob

In answer to your questions

Right then, Paul………..What four motors do we need?….Get it right this time…lol

What motors do you have in your store cupboard? 500s / 550s / 600s or another pair of 700s all of these will do, but get the wiring right this time….rofl

Would look really nice with two multi drives! The boat will look fantastic with a twin pair of large motors.

On the Brutus video, did you hear Duckie say that we needed some exhaust pipes…..He really mean't silenscers

But what a good idea? From my point of view its not a good idea as if I had wanted extraneous (look it up Ashley) decoration I would have included it on the drawings but the boat is yours to do with as you please.

Mike

I can supply the drawings in most formats which can be issued directly to the laser cutting company, all you would have to do is tell them that the primary file is written on TurboCad (.TCW file) and then ask them what transfer file is best for their system i.e. .DXF / .DWG / .SWG.

If you wish I am happy to converse by email with the company and issue the files directly to them.

Dave

I agree all of this jumping about has really confused me…..Jane says its easily done

Paul

[Diede van AbsParticipant @diedevanabs87670]

Maybe ask colin to move some of the Brutus stuff over to that thread? Or is that not possible with this particular forum software?

[Colin BishopModerator @colinbishop34627]

The software is bespoke which means that I cannot move individual posts from one thread to another, people just need to think a bit harder before they post to keep things on topic. i.e. it's all your faults!

Colin

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