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[vnkiwi]

Hi Rich,
You need something like this.
But keep the end of the prop shaft at the motor coupling as short as possible, to get the end of the brass tube as close to the motor as possible.
cheers
 

[U-33]

Yep, got it...thanks, VNK, much appreciated.


I'm thinking that a complete rethink of this build is needed...I reckon that the hull is too small, in both length and width. Last time I tried it in the bath it was very unstable and kept falling over, now it does the same only worse...every time I operate the steering it just tips over.
So, I'm going to start again I think...I need to source and bigger/wider/deeper hull to start with, about 36'' x 5''. I can incorporate all the ideas from this one into the new one, just increase everything by half again. I'll be spending today hunting round various companies websites looking for a new hull...more expense. 


Rich

[U-33]

I couldn't find a suitable hull to replace this one, so I've been cracking on with what I've got...fingers/hands permitting, they have been really bad recently. Anyway, I put the boat in the bath this morning to see what would happen:how much more lead does the thing need?

In the forward cupboard is all the radio gear (Planet rx, esc and associated wiring), plus a custom made lipo battery, the spaces under the floorboards are already lined with lead sheet, and even then I had to add what you see in the picture. Gawd knows how I'm going to hide this lot.

The word ''challenge'' springs to mind....

Rich

[hmsantrim]

Hi Rich.
 maybe you need summit like one of they "corneto canoes"     they have a similar look to your photo no1 a canoe with pointy ends.
 
frank

[U-33]

I need something, Frank...trouble is, I don't know what I need    I'm wondering about something like a one metre yacht hull, that would give me a bit of extra length and beam to play with.

Something like this, maybe.. http://www.ebay.co.uk/itm/FIBREGLASS-MODEL-BOAT-YACHT-HULL-/231336096468?pt=UK_ToysGames_RadioControlled_JN&var=&hash=item35dcb4b2d4

The search continues...

Rich

[Subculture]

Your centre of gravity is too high, simple as that.

You need to go much much lighter. i see lots of very heavy brass, plus the heavy 400 motor. Think of using a carbon fibre stern tube, and a hollow prop shaft. Use lipo for the batteries, and keep everything as low in the hull as you can. if it still rocks and rolls, you may need a keel.

[Big Ada]

If ONLY I could post photos of my Longtail Boat maybe they would help.
I have tried numerous times but Too big, so frustrating.
 
Len.

[U-33]

Andy. it's not the rocking and rolling that worries me, it's hiding the lead ballast. There's no more room under the floorboards to put anything else. The battery is a 7.4v 800m/amp lipo running the length of the forward cupboard, right in the keel. The coupling is due to be replaced any day now with an alloy one, and the prop shaft is very thin walled brass tube,  plastic bearings, with only a 2mm shaft inside it, and a plastic prop.
The motor is a 400 size, it's only a 260 one.


Len...you can email me the photos if you'd like, pm me and I'll send you my email address.




Rich

[hollowhornbear]

why not fit a couple of outriggers?

[U-33]

But wouldn't that make it more bouyant, Kev? I 'spose I could fit a lot of ballast into two outrigger hulls, tho...


Rich

[hmsantrim]

Hi Rich.
 maybe you should go for one of these instaid
http://www.rcmovie.de/view_video.php?viewkey=1cca999f55a43db2ce04
 
 Frank 

[U-33]

That's marvellous Frank, I do like that! Brilliant stuff!

Rich

[vnkiwi]

You could try something like this for your ballast. The old bar solder, your plumber used to use, would do.
They once came in 12" lengths, and are the right shape, or you could cut and laminate up strips to make the shape
I've done this a couple of times, worked for me
cheers
 

[U-33]

I've managed to get three pieces of lead under the floorboards, plus the piece that was already under the floor in the bows, hopefully this will help a lot. Extra lead will be in the form of lead shot, placed in bags, and positioned as and where needed, and made to look like bags of 'stuff'.

Back in the bath again later for more testing...the end is getting close now.

Rich

[U-33]

If the worst comes to the worst I'll add a stainless steel keel underneath, something like as in the pic below.

Rich

[Subculture]

Better to use lead than stainless as it's almost 50% denser. Also if possible melt it into a continuous block- shot takes up a lot more room, as you end up with quite a bit of air.
 
I once used lumps of tungsten in the keel of a 575 yacht. That's much denser than lead, but more difficult to work with.
 
A keel may be necessary.
 
 
 

[U-33]

Better to use lead than stainless as it's almost 50% denser. Also if possible melt it into a continuous block- shot takes up a lot more room, as you end up with quite a bit of air.

The lead shot will be in open bags, Andy...quick coat of paint and the cargo will be bags of oranges or something similar.
I once used lumps of tungsten in the keel of a 575 yacht. That's much denser than lead, but more difficult to work with.
 
A keel may be necessary.

I'm thinking the same, it'll keep the weight low and help keep the boat upright in a breeze...there's a canopy to go on yet, get a breeze underneath that and I'll have a long tailed yacht.

[tobyker]

Why not just build an under-floor compartment for the lead? Nobody will see it when it's in the water, and you can still have a nice clear floor for fishing nets and old school Thais. The bulge will also give you a bit more buoyancy and stop the ballast sinking the hull too deep.

[U-33]

''old school Thais....''  you're fired!

There's no more room under the floorboards, it's full of wires from the esc to the motor and from the rx to the steering servo, plus three large strips of lead.

BUT...you've given me an idea. A length of styrene tubing, sealed at both ends, filled with lead shot, and bonded to the outside of the hull bottom, and then faired in with a spot of filler. Final ballasting can be done by the bags of lead shot painted to look like some sort of fruit and placed on top of the floorboards.

I'm working on it...if these bl**dy fingers would cooperate.

Rich

[Netleyned]

I suppose the steerer will be wearing a Thai Dye sarong


Ned

[U-33]

Taxi for NetleyNed...

Rich

[hmsantrim]

Hi Rich.
 here ya go plenty of model detail here.  Think you may need the bicycle clips on if you want to go racing in one of these may need to scale yours up a bit though. 
http://www.john-tom.com/Klong16/LongTail.html
 
 Frank

[U-33]

To all intents and purpose, the long tail is now completed. Two more little jobs to do...make a better set of clothes for the crew man, and fit a smaller prop. I have a 25mm x 2mm prop coming from Cornwall Model Boats, so when those two little jobs are done, the boat is finished. I may dirty it up a bit more, especially the woodwork, not sure yet, and I might titivate(old Sussex word for fiddling about)it a bit here and there.


It's been in the bath and it does stay upright(just)but it's going to be a flat calm water boat, and only going forward...going astern she just fills up with water.


Thanks to everybody who contributed to the research and the build, it's been a real challenge to build the thing, and to hide all the electronics away out of sight in a hull measuring 25'' x 3''.


The next project is already in the research stages...well, two actually. A one man chariot midget submarine is already started, and a WW2 US small river patrol boat is on the drawing board.


Rich