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[npomeroy]

My first boat project - in my senior years I'm retiring from RC scale helicopters which are fairly high-stress to fly. I've built a few 1/8 scale light aircraft from scratch as display models based on 3-view drawings and photos. The Damen tug is a charm-less modern type but I like the look of them, I could easily find GA drawings and the superstructure is fairly simple (for a boat). Being a hard-chine type I could work out the cross sections from the 3-view drawings, although blowing them up from the brochure PDF required some interpolation.


The hull framework will be laser-cut 3mm ply, with 1mm ply sheathing. The above-deck cabin will be clad mostly in 1mm ply with some sort of internal framework. I have just today done a prototype window frame https://www.modelboatmayhem.co.uk/forum/index.php/topic,68744.0.html .


I've bought the motors Mabuchi RS-555PH-3255 and speed controllers. I've ordered a bow thruster from UK and foolishly thought I'd save shipping costs by directing it my wife's family in the Netherlands, who she is visiting, but after paying EU VAT plus an unexpected EU customs cost of about 30% (email from Post-NL), it would have been significantly cheaper and faster to send it direct. Oh well.

Attached are some of the hull frame parts and a an example image. Not sure of colour scheme yet.

Cheers
Nelson

[Hande]

I admire scratch building skills! This will be fun to follow.
Sorry about my ignorance, but surely Damen 1907 doesn't refer to the original build year? The looks and propulsion gear are pretty much 1960's - 70's
Hande

PS. Helicopters - wow !!

[chum444]

Here’s a photo of a Damen 1207 Stan tug I built a couple of years ago.

[chum444]

Any progress?

[npomeroy]

Any progress?

No not really. I did some 3d printing for the window frames.  Distracted by slow completion of 1/6 helicopter model, and on a whim making a 1/32 plastic kit of the Su-27 jet. 


It's been so long I wasn't sure where this tread was so I asked a question in another section
https://www.modelboatmayhem.co.uk/forum/index.php/topic,70214.0.html


re-thinking the frame construction.

[1967Brutus]

I've ordered a bow thruster from UK and foolishly thought I'd save shipping costs by directing it my wife's family in the Netherlands, who she is visiting, but after paying EU VAT plus an unexpected EU customs cost of about 30% (email from Post-NL), it would have been significantly cheaper and faster to send it direct. Oh well.

Those are the blessings of "Brexit"...

FWIW: There are a few excellent shops in the Netherlands as well, probably selling the same items. That could have saved you quite a bit, depending on the original country of manufacturing.
But it also is a bit a matter of luck, sometimes these packages slip through.

It has been quite a while back ('89~'90) that I visited Hawkes Bay NZ, but I remember meeting a few dutchies ther and coincidence had it, they were from my birthplace and knew people I knew as well. Heck, my parents allready knew about the encounter even before I could tell them...

[Umi_Ryuzuki]

Since Brexit, shipping to the UK, Netherlands or Europe has gotten more complex.

I know retailers that  were told they needed to collect duties for the Crown.
They needed to register, collect the duties and submit the duties each year.
But they needed a British Tax ID, but they weren't British, So they couldn't register.
... In frustration, to the idiocracy of it all, they proposed a new "Tea Party". 
.

New, this year, ... To send a package to the Netherlands from across the pond, it is a $13.00usd fee, plus 43% of declared value.

[1967Brutus]

New, this year, ... To send a package to the Netherlands from across the pond, it is a $13.00usd fee, plus 43% of declared value.

Is that from the US?

How are things when I would ship something from the Netherlands to the US? Because I believe a small package to the US is 10 Euro, no percentage. Does the recipient pay a tax on declared value?

I know that purchasing stuff from the UK has gotten a fair bit more expensive since Brexit, but purchasing from the US has become prohibitively expensive since quite some time (way before Brexit anyway)...

[steve mahoney]

Getting some props from Raboesch in the Netherlands to NZ cost as much in postage as the props themselves. Oow!
And now the NZ govt charges 15% on anything mail order. Double oow.

[1967Brutus]

Getting some props from Raboesch in the Netherlands to NZ cost as much in postage as the props themselves. Oow!
And now the NZ govt charges 15% on anything mail order. Double oow.

Try to combine purchases... I could send quite a few props for only 12 Euros, and since that would not be a mail order as such, but a private person sending you a box of "loose items", could save you the 15% mail order fee...

I've done it before, and it's just a thought...

But we're hijacking this thread, and I'm in part to blame for it. Apologies to the OP.

[npomeroy]

Try to combine purchases... I could send quite a few props for only 12 Euros, and since that would not be a mail order as such, but a private person sending you a box of "loose items", could save you the 15% mail order fee...

I've done it before, and it's just a thought...

But we're hijacking this thread, and I'm in part to blame for it. Apologies to the OP.

That's OK, but as penance, perhaps check out my other thread I linked above, and see if you can comment.


As for import costs, indeed imports to NZ outside Amazon and the big traders do not automatically attract 15% tax.

[1967Brutus]

Done

[npomeroy]

I'm back on track. The outlines shown in the first post have been superseded now. I'm battling with the design of the framework for the deck, as I want a large part of it to be removable for access to the electrics for troubleshooting, and it is a compound curve. I'm considering deleting the slight centre rise (presumably to aid water un-off on the full size, but hardly relevant from that POV on a model), although that seems a bit of a scale compromise. Also I want to have a fairly good watertight seal so the mating surfaces need to be right.
I'm not necessarily looking for answers right now - I am working on it, and will post updated outlines later.

[npomeroy]

Here are the outlines ready for submitting for laser cutting. The 3mm sheet is the keel, ribs and some other parts. The pink-tinted parts are part of the fixed hull - the greenish parts are of the removable deck. On the 1mm sheet the wider part forms the deck margin, and the narrower parts fit into the slots on the rib to define the chine seams. These parts will curve as fitted, and so calculation of the lengths between each rib station required a combination of Pythagoras and length-of-an-arc-given chord-and-radius. Based on x y z positions from the GA drawings most of the points were worked out in Excel and applied as xy numbers in Inkscape. Overall length is about 600 mm. The pink parts on 1mm are the bulwark posts.

[steve mahoney]

They should slot together nicely after cleaning up any charred surfaces. Are you laser cutting a deck at the same time?

[npomeroy]

They should slot together nicely after cleaning up any charred surfaces. Are you laser cutting a deck at the same time?

Those parts form the frame for the main deck. I'll surface it with 1mm rectangles to more or less mimic steel plates. The superstructure is still at the drafting stage and I'll probably cut it by hand. Window frames and doors probably resin-3D printed. How much do the burned edges interfere with gluing?

[JimG]

When laser cutting getting the power right is the first job, a good cut will be a light brown colour with little charring, this is easily cleaned for gluing with a little sanding. Too much power leaves a blackened charred edge which needs a lot more work to sand down to cleaner wood, much of the charring is the glue between the ply layers which stops the wood absorbing the glue when joining.
Jim

[npomeroy]

When laser cutting getting the power right is the first job, a good cut will be a light brown colour with little charring, this is easily cleaned for gluing with a little sanding. Too much power leaves a blackened charred edge which needs a lot more work to sand down to cleaner wood, much of the charring is the glue between the ply layers which stops the wood absorbing the glue when joining.
Jim

All good Jim.  It's being commercially done, so I have no control over those parameters. It will be interesting to see how much sanding is required: the cut dimensions are supposed to be accurate to 0.1 mm and there are slots to take ply thickness, which in itself won't necessarily be exactly the nominal 1 or 3 mm.

[steve mahoney]

3mm ply can burn a bit – the glue in the ply doesn't react well. Birch is not too bad but Meranti and Hoop Pine can char pretty badly. I usually wash the cut pieces in warm soapy water, and lightly sand the edges when dry. Makes gluing easier and prevents soot getting everywhere.

[npomeroy]

So, I've received the laser cut parts. The initial set of 3mm parts was a disaster, apparently due to the sheet not sitting flat on the cutter so over half the parts were not cut all the way through. And it was hard ply and a mission to cut them by hand. Also operator did the offset on the wrong side so the dimensions were out which made some of the interlocking fits sloppy. It has been re-done for me with poplar ply and I'm happy with the parts now. I made a few mistakes in some parts which required some modifications, but happy so far. Here are some images of the hull frame test fitted. There are two 1mm thick chine longeron that fit in the slots. There is also part of the framework for the a main deck insert which will be lift-out.

B1 stern view by Nelson Pomeroy, on Flickr

B1 frame 1 by Nelson Pomeroy, on Flickr

[steve mahoney]

Make sure the images are .jpg files and less than 1MB each.

[npomeroy]

It's OK thanks. ChatGPT helped - said to use the BBcode version of the Flickr link and just paste it in. Worked.

[npomeroy]

This is totally scratch-built, based on 3-view GA drawings on the Damen sales info.
So, the hull frame is all glued. There are will be some sanding and adjusting shapes with some slivers of wood stuck on. But ready for the next step.

It is tempting to glue on the hull sheeting (1 mm ply - one sheet each side for each chine plane) next, but I wonder if it is best to first work on the motor and other placements in the hull. These might be easier if I can access from the side between the frames. The chine lines are dictated by 1 mm curved ply longerons. This presents a very small surface for gluing the sheeting, so I am thinking of adding 3 mm blocks to the longerons (say 10 mm long, 2 or 3 per inter-frame space). I may also add 1 or 2 vertical members (3 mm ply) stuck longeron-to-longeron in each space.

30Jan frame by Nelson Pomeroy, on Flickr

[npomeroy]

I decided it was best to install the running gear, or at least the mountings for, before adding the sheeting to the hull. It's all scratch built so am working it out as I go.
So I have installed the bow thruster. and am working on the removable deck. The individual rectangles will be gap-filled and smoothed, and form the compound curve of the deck (I've imitated what appears to be a slight camber beam-to-beam on the full-sized version).


Bow thruster 1 by Nelson Pomeroy, on Flickr


Deck off by Nelson Pomeroy, on Flickr


deck on by Nelson Pomeroy, on Flickr

[npomeroy]

I've made the first Kort nozzle. The circumference is sheathed in 0.1mm brass, and lined with resin 3D printed foil cross section. I made that in four parts to better fit on the build plate and to allow some adjustment of the circumference. The holding box is from thicker brass.

Kort assy whole by Nelson Pomeroy, on Flickr

kort parts by Nelson Pomeroy, on Flickr