Slo mo Shun

[Dave MilbournParticipant @davemilbourn48782]

Bob

24v is no problem at all for the planned motors and ESCs, but leave the SLA batteries for the old Vincent 1000, my good man.  Toooooooooooo heavy by a huge margin.

Best advice, based upon Mr D Jones’ 49″ Perkasa, is to use two x 12v sticks of 4600 mAH NiMH Sub-C cells per motor, connected in series to give 24v. The weight of this little lot (i.e. 4 packs) totals 2.7kg, c/w 10.5kg for your four 12v x 7AH SLA batteries. Those lead-acid bricks would be unlikely to provide the current that the big 900 motors will require at that voltage anyway.

Ref cooling, Dave’s 900 motor has an ali coil wound round it, fed with the usual water-scoop, but the P98 ESC heat-sink fins stay lukewarm at their hottest.

As the geezer wot designed the Precedent Huntsman it gives me untold grief to see one of them trundling around a pond, its back breaking under the weight of a lead-acid battery. After all the work you’ve put into this beast ‘t would be a tragedy indeed to fit an electrical ball-and-chain into it. The “plane” in “hydroplane” doesn’t really work with the “lead” in “lead-acid” – OK?

 

Ashley – once you’ve handled one of these 900 jobs then you’ll never look fondly at an 850 again.

Dave M

[Bob Abell 2Participant @bobabell2]

Well, thanks a lot Dave!

 

I`ll use exactly what you`ve just recommended. Sounds  great to me, pal!

 

How would I charge these batteries?

Can you supply a harness that simply conns the batts up in the correct polartity, please?

 

Any thoughts on the props?

 

In the meantime, all the best to you, Dave and all the forum members

 

Bob

[Dave MilbournParticipant @davemilbourn48782]

PM sent.

DM

[Bob Abell 2Participant @bobabell2]

Here`s the fancy rudder mechanism with the air rudder incorporated

 

Push / pull wires from the main bellcrank,will enter the hull at the real…….to the servo

 

The wood blocks will have the customary rivetted card effect, in due course….painted red and suitably distressed of course!

 

Bob

[Phil Winks 1Participant @philwinks1]

Posted by ashley needham on 30/12/2009 19:24:00:

OK…

 

5.6kg for the boat, 2.65 for the 12v 7Ahrs gell battery = 6.35Kg    48″ long by 13″ wide.

 

 

Ashley

 Er isn’t that 8.25kg

Edited By Phil Winks 1 on 31/12/2009 20:19:34

[Phil Winks 1Participant @philwinks1]

Anyways its getting on now and the vino is open so happy new year to one and all

[Bob Abell 2Participant @bobabell2]

Morning Chaps!……….Happy New Year to one and all!

 

Ashley………When you`ve finally sobered up ……….and finished your search for a……… Little Drummer Boy………..and got your sums right………..as Mr Winks marked your card….

 

When the lakes come clear again……..Would it be possible for you to add 10lbs of ballast in your Fantomeand see how it performs?……….Speedwise

 

I reckon the overall speed would still be acceptable?

 

 

Bob

[ashley needhamParticipant @ashleyneedham69188]

10lbs !!    I will give it a go, I will have to use my stock of 6v gel batteries as ballast.

 

I can imagine it would still be nippy, as far as comparing it to anything “scale”…tugs/warships etc. Its a shame i dont have a pair of 850s to try as this might be more of a taster to performance at this weight.

 

Just another thought…you could make a clear acrylic box (detatchable) to fit  underneath Slomo in order to fill in the step and give a much better underwater shape (for  medium speeds of course only) in the case of insufficient engine power ?

 

On the Sunderland, I had the bottom of it stepped, in order to look a bit better and more true to scale (not that the rest is, but sideways on it looks pretty good) but then thought, in the light of less-than-sea-skimming performance, that in retrospect this might not have been a good idea and a dead smooth bottom would have been best….so I filled in the step. It has made SOME difference, but as I have gradually tweaked a few other things its hard to tell…

 

I did read that for maximum lift, a dead flat bottom is best, and so there is no chine on Shorty. As a disadvantage you get absolutely no lateral control when going fast, but this is not so much of a problem on a craft with a big air rudder, wings and (effectively) outriggers. …and not going that fast!

 

Ashley

[Bob Abell 2Participant @bobabell2]

Fellow Forum Posters!

 

I would like to wish, on behalf of all the forum members, “all the best for the New Year” to our long suffering friend……..Paul……….. The Fat Controller……as he must not in the best of health at the moment

 

I personally miss his friendly advice and witty remarks, especially on the Slo Mo Shun thread

 

We wish him a speedy recovery to reasonable health and look forward to his eventual return

 

Paul, come back soon!

 

Bob and friends

[Phil Winks 1Participant @philwinks1]

Thanks Bob and the same to you and yours and also to Paul I think Bob said it for all of us.

 

Ashley the reason for the step in a flying boat hull and on floatplane floats is that without the effective shortening of the imersed hull said aircraft would never get of the water. even with that it takes an average of 40-60% more power to get a seaplane up as opposed to its wheeled twin. I once built a walrus and with wheels down all it required into a light headwing was half throttle as oposed to full and a much longer run on water the trick was to hold down elevator in untill the tail lifted the rear of the hull up then it lifted of with ease such draggy sticky stuff water I do think though that with  DM’s recomendations Bob will have little difficulty getting on the plane the question really is can he find a big enough lake and when its up how long will those bty’s keep it up

[Bob Abell 2Participant @bobabell2]

Thanks Phil

 

All I want, is to see the model……on the plane only occasionally…….just the odd burst of power only now and then………the rest of the time, simply burbling around the lake….showing off!…………..and hopefully making a realistic engine sound

 

There`s no chance of tearing around the lake…….Too much wildlife and I don`t want to attract the disapproving public gaze!

 

I like the idea of 24volts………two motors and twice the power!……..yummy!

 

Here`s hoping for good results………Bob

[ashley needhamParticipant @ashleyneedham69188]

I am dithering a bit like you, Bob, with my Turbinia. Just like you I am theorising as to what engines/power I need to turn 9 screws without overloading the engines, whilst providing a brisk performance.

 

 

 

However, what REALLY needs to happen is get my arse in gear with a bunch of motors and an ammeter and head for the sea (ok, pond) and see whats what. 

 

A bit like yours, Turbi only has to go fast enough for effect. Lift the nose out the water and provide lots of prop froth at the back.  Ultimate performance is not whats needed, as long as its brisk. There is little fun to be had on a pond full of wildlife trying to go full pelt for 5 yards and then swerving or slowing down.

 

I get at least an hours brisk motoring and swanning around with the Fantome, and so i would expect a similar performance/endurance from yours if you had a pair of 850`s and a pair of 12v 7Ahr batteries (for instance).

 

Fit a wire drive system for parallel props and leave room for a pair of large motors and stick it in the oggy and see whats what. You never know..

 

In the Classic boat museum on the Isle of Wight, there are several fast powerboats and without exeption they all seem to have toddy little props and humungeous engines. it may be that a pair of 12v 700`s and 40mm Cleavers or whatever they are called, will provide sufficient action, especially if used with a stick of 12v NiMh cells to keep the weight down.  ?

 

Ashley

Edited By ashley needham on 03/01/2010 08:12:57

[Bob Abell 2Participant @bobabell2]

Hello Ash the Dash

 

I`ve actually seen The Turbinia in a museum somewhere……….could be Liverpool Maritime or Duxford……….I`ll take a better look at it next time.

 

Why not three 540`s in your Turbie……..What`s the pipe on the bottom doing?

 

How big is your model?

 

Bob

[Bob Abell 2Participant @bobabell2]

Rudder mech painted and finished……….Needs a bit of distressing yet!…….To give it the Ali look…………Bob

[Bob Abell 2Participant @bobabell2]

Had a great idea for animating the driver……….I`m using wood dowel for the arms and across the shoulders……….All connected together with a loose`ish cord for complex movement…………..Now need a woolly jumper to hide it all

 

Should be quite a novelty, seeing the driver turn the wheel in tandem with the rudders?………..Hopefully!

 

Bob

[ashley needhamParticipant @ashleyneedham69188]

Looks great. I stick things like your rudders on my buffing wheel. This takes off the sharp corners on the edges and small scratches, and  makes it smoothy and shiny.

 

Personally, I would go for as much movement on the steering wheel as possible, as small amounts of turn may go unnoticed. Will the driver lean into the bend, or his head loll over..? A silk scarf flowing in the wind would be very twee…

 

The little tube/hole on Turbi`s bottom is for the rudder shaft ~(unfilled there of course). This item sits awkwardly to one side of the centre shaft ..there not being a conventional place to put it. The centre prop sticks well out the back and the wing props are very deep, making twin rudders even deeper.

 

As to motors, a 540 may be ok for one 30mm prop, but what about turning all 3 on a shaft?? or, as I might suspect,on a model such as this the 3 props are actually only theoretical, as the first one speeds the water up for the second and so on, the rear prop doesnt actuall bite into as much water as the first??

 

Ashley

Edited By ashley needham on 03/01/2010 18:05:06

[Bob Abell 2Participant @bobabell2]

Hello Ash

 

The silk scarf is a good idea and would look the bizz!……..but there may not be much of a breeze!

 

On your Turbie………..How about three props……..in three sizes!……..the biggest at the rear?…eh?

You might get a turbo effect

 

I`ll buff up the Ali bits shortly…….might even add the swirly wheel finish with fine emery on the end of a 3/4″ dowel……..think it`s called ..”engine turning”

 

Bob

[Bob Abell 2Participant @bobabell2]

Just a quickie…

 

I`ve rigged up the driver to the steering wheel, but I`m only getting 45 degrees max rotation either way on the servo?….Is this the correct amount of rotation?

 

I could try my other servo`s but it`s not convenient at the moment

 

Bob

[Paul TParticipant @pault84577]

Hello Captain Bob

 

The Slo Mo Shun is looking really great, are you happy with the model now?

When are you going to sail it.

Sorry I have been offline for a while (the old ticker needed winding up)

 

Paul

 

[Bob Abell 2Participant @bobabell2]

Welcome back, Paul, and a belated….Happy New Year!

 

I`m very pleased with Slo Mo, appearance-wise…….but it will be a shock to the club members when they see it!……….Nobody in our club, apart from Duckie, ever look on the net!…….Out of 140 members!…………..I really can`t understand them at all

 

At the Mo, I`m working on the animated driver, which is very amusing to see, turning the steering wheel……..Our little dog is fascinated by it

No pix yet as the drivers jacket is not too clever

 

Got the motors etc ordered now from ACTion Man…….but I`m in no rush to get it on the water……………as a matter of fact, we aint got no water……the lake is frozen solid

 

I`m also rubbing dark acrylic paint round all the louvres and bits and pieces, to get rid of the ” just made ” look……………and the effect is delightful!

 

Look after yourself, Paul, take it easy, take your pills and gerrup them stairs!

 

Dr Bob

[Bob Abell 2Participant @bobabell2]

A few pix of Bob The Driver, posing for the media!

 

Bob the Builder

[Phil Winks 1Participant @philwinks1]

Looking very good Bob and I’m sure that 45 degrees is about right any more and the driver would need to shuffle his hands on the wheel however if you need more how about a 10mm pulley on the wheel shaft, with a 20mm one on the servo that would give you a total of about 120 degrees of movement (60 either side of centre assuming your servo moves 60 from end to end) and no worries about going over centre.

 

Welcome back Paul and a belated happy new year here’s hoping its a good one for you

 

Phil

[Bob Abell 2Participant @bobabell2]

Thanks Phil

 

I`ll stick with 45 deg each way as the mechanism is already finalised!

I`ll try the pulley speed up, sometime later, if required

 

We`ve got about 8″ of snow up here!

 

Bob

[Phil Winks 1Participant @philwinks1]

the official figure for snow in somerset was up to 15cm however I measured 25cm on our  car roof yesterday. it reduced a little through the afternoon and has frozen hard overnight so I’m guessing our little pond has frozen by now. however I’d bet the river hasn’t. Thats a good size club you have there Bob 140 members!!! we’re much smaller with 25 ish and only about a dozen that are active so 8 sailing is a good turnout lol.

[Bob Abell 2Participant @bobabell2]

A few more pictures……..Hope you don`t mind……..Photography is my 2nd hobby

 

Had to make a smaller steering wheel……..Bob the Driver was too fat for the chimney!…….The smaller wheel also emphesizes the steering action too

 

Bob

 

 

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