wefalck

As promised, a bit of an update of the progress.

I have glued in the first and last full frames, and have started to fit in the rest. I will wait with gluing them in until I have the full set, and can use some small distance pieces between to get the spacing evenly distributed.
 
 

I have a colleague in Germany (retired engineer with a good pension and no family), who got himself a Formlabs 3 printer, which I think set him back by some 6500 €, but it quite amazing what he is turning out after only a short learning period. The main hurdle - apart from the money, is being sufficiently CAD-savvy. He used AutoCAD in his job, so he knows what he is doing. A lot of the stuff he prints he has actually professionally cast in brass - the company get the models and he gets one set of brass parts for free, while the company sells them to other customers. The brass parts seem to need very little clean-up.

It seems that only the technology that uses UV-curing resins is good enough for our purposes, but that involves messing around with volumes of monomer, which is not so nice. Prices have come down dramatically, but you are still talking a couple of thousand Pounds, Euros, US Dollars ...

Dear Pat and Keith, the etchings were the result of my foray into that field in about 2008. I tried to develop for myself the technique as a sort of ad hoc process, i.e. you draw a few parts and then go away and do the etching, as you would go to the lathe or milling machine.
 
Not having a 'wet laboratory', I tried to reduce the volume of liquids involved to a minimum and worked in plastic film-containers (still have a good supply from my intensive slide-photography days, before I went fully digital in 2009). In consequence, the 'frets' were the size of two large stamps the maximum.
 
I found the idea of contracting out the production of the masks and of the etching difficult to organise, because one has to fill an A5 or even A4 sheet to make it cost-wise viable. This means that you really have to have a very good idea of all the parts and their exact sizes. Which in turn means that the project has to be fully designed, before you start making any chips or swarf. That's probably fine, when you work from commercial model-builders drawings, but is difficult, when you are trying to interpret some contemporary drawings and images as you are going along. Perhaps I should have done it like this ...
 
The more or less round rivets and the 'draft' along the raised edges are probably a (wellcome) artifact of my etching method. The sheet to be etched is agitated by moving it vertically in the film container or rotating it. This results in a predominantly lateral flow of the etching solution, which leads to quite a bit of 'underetching' underneath the photoresist. In the commercial process of spray etching, the solution is sprayed vertically onto the sheet to prevent exactly that underetching, resulting in much sharper and vertical edges.
 
I gave up etching (for the time being), because the main problem was to obtain films with sufficiently dense blackening with neither my laser-printer nor my ink-jet printer. Given the small sizes of the parts, this was difficult to correct. If you make printed circuit boards, you can easily touch up your lines and areas with a permanent marker, but here I was really pushing it to the edge of the technology.
 
I was thinking of giving it a try again by coating the sheet metal in black paint and then burning it away with the laser-engraver. Should work for single-side etching, but my little cheapo laser-engraver has no facility to sufficiently precise (say within a 1/50th of a mm) register a piece, once you have flipped it over.

We all make mistakes like this ... particularly, as we get older and don‘t remember what we did before

How were houses painted in the area ? I gather in some areas of the USA wooden houses were painted in red ochre, as is for instance common in certain Scandinavian areas. So, if red ochre paints were around they could have used those to mimic the common practice in other areas of shipbuilding. In the 1860s ship bottom paints (for iron ships) became available in quite a range of colours, but red seems to have been always popular, probably because people were used to the brownish-reddish colour of copper sheathing.
 
Otherwise, I would concur with Roger, that some sort of tar would have been the most likely alternative.

A few month ago I acquired a KKMoon K4 3W miniature desk-top laser-cutter and it has proven to be a useful investment. Therefore, I would like to share a few operational insights, though you can find a variety of ‘test’ videos and the like on the Internet.
As with many Chinese products of this kind, it comes in various guises and configurations that may be mechanically identical or not. The traders’ descriptions are often somewhat haphazard and also suffer from translation issues. I am not sure, whether KKMoon is a trader or a manufacturer, their Web-site does not actually list these laser-cutters.
Prices between the different offers on the Internet marketing platforms can vary as much as 30%. However, I paid just over 100€, shipping included.

Image of the laser-cutter as advertised
 
 
 
The stated main specification of the machine I bought are
 
 
- Size: about 155 mm x 166 mm x 143mm
- Weight: ca. 600 g
- Laser Power: 3 W (3000 mW) – blue = xxx nm wavelength
- Engraving Area: about 80 mm x 80 mm (3.1" x 3.1")
- Engraving Depth: about 1 mm /0.04" (Adjustable in the range of 0-1 mm)
- Mechanical resolution: 0.05 mm = 512 dpi
- Supporting System: for Windows XP / 7/8/10 and MacOS 10.10 or later
- Supporting Image Format: JPEG / JPG / PNG / BMP
- Connectivity: Micro USB B to USB A (cable included)
- Frame Material: ABS
 
 
The laser-cutting system consists of three main components that determine its capabilities: the mechanics, the control board, and the software.
 
 
Mechanics
 
The mechanical resolution of 512 dpi is not that brilliant, if you compare this with modern scanners or printers, but then mechanics have their price.
The 3 W diode laser has an adjustable focal point.
 
 
Control Board
 
I know next to nothing about electronics and commercial products, such as the control board that is being used in this machine. It would be particularly interesting to know, whether the board could be driven by other types of software. Perhaps someone from the Forum community has insights into this.
 
 
Driver
 
The software consists of two components, the driver and the cutting software itself. The driver is a standard piece of software under MS Windows and either comes with your MS Windows configuration or can be downloaded from the software producer’s Web-site. The driver runs under MS Windows XP/7/8/10. I am using an oldish mini-laptop with MS Windows XP on it. The driver unfortunately does not run under MS Windows emulation Parallels under MacOS 10.7.1, nor under the iOS for the iPad pro. The cutting software, however, seems to run in Parallels under MacOS 10.7.1. It should also run under MacOS 10.10 and higher, but I could not test this.
 
 
Cutting software
 
The cutting software is a very simple piece and is based on bit-image processing. In other words, the image is processed line by line from the top down and whenever a black pixel is encountered, the laser flashes. As noted above, the software can handle JPEG-, JPG-, PNG-, and BMP-files, but not TIFF. Images of up 1600 x 1600 pixels can be processed.
There are three variables that can be adjusted to control the cutting process: the laser power in %, the cutting depth in 0.01 mm increments, and contrast (0 to 256). It is obvious, what the power adjustment does and I assume the cutting depth is determined by the length of the laser pulse. The cutting speed cannot be adjusted explicitly. What influence the contrast setting has is not completely clear to me, as the screen appearance of the image changes, even when I use a 0/1 b/w bit image. In practice, however, it does change the width of the cutting traces.
The image to be cut can be freely moved around the cutting area of 80 mm x 80 mm on the screen.
 

Screenshot of the cutting software user interface
 
Set-up
 
The machine is mobile and in principle does not require any special set-up apart from a flat surface. However, any energy penetrating the material cut will be taken up by the surface on which the machine stands. This means that the material has to be fire-proof. I happened to have a piece of roof-slate at hand, which turned out to be very useful for the purpose. Pieces of marble or tiles would do as well.
The laser beam needs to be focused onto the material to be cut. The machine comes with a piece of black cardboard for the purpose, but this is thicker than many of the materials to be cut. It is better to focus the beam on the material in question. The laser spot is very bright, making it difficult to see, whether its size is minimal. I found it useful to illuminate the cutting area with a strong table lamp so that the contrast is reduced during focus setting.
The material to be cut needs to lie absolutely flat. I have been thinking of making some clamping rails or similar. It turned out that short tabs of cellotape are quite sufficient for the purpose. The small pieces of material are just taped down at each corner onto the slate.
 
 
Cutting times
 
I did not make systematic tests, but the examples shown here took about 10 minutes to cut. I would estimate that covering the full 80 mm x 80 mm cutting area would take in the order of about one hour.
 
 

Steering wheels cut from 0.15 mm thick Canson paper (120 g/m2) (cutting area about 40 mm x 40 mm)
 
 
 
Capabilities
 
Whether a material can be cut by laser depends on a number of properties of the material in question. First of all the material must be either combustible or it must be able to be evaporated. The material must be capable to absorb enough energy to reach its combustion point or its evaporation temperature. Whether a material can absorb enough energy depends in turn on a number of factors.
A key factor is its albedo, in other words, how well the material reflects or absorbs light. Bright and shiny materials reflect most of the light, as do white and light coloured materials. Hence they are not absorbing enough energy. Conversely, dark and in particular black materials absorb most of the light that is shot at them.
Another factor that determines how much energy is needed to combust or evaporate it is its volumetric density. Compact materials with no pores contain more mass per volume than porous materials and hence need more energy per volume to combust or evaporate. The volumetric heat conductivity is also important. If the material conducts heat well, the energy transmitted may become dissipated before it reaches the flash-point or the boiling-point.
While in theory virtually all materials could be cut with a laser, in practice the available laser may just not be powerful enough.
In practical terms this means that it is not possible to cut metal and transparent or translucent materials with this small laser. The 3 W laser just does not impart sufficient energy to melt and evaporate metals. Not surprising though. Plexiglas or tracing paper let all or too much of the light pass and therefore cannot be cut.
Bakelite paper has a high evaporation temperature and is translucent. It can be cut through in thicknesses of up to 0.1 mm, but edges become charred. A strategy can be to only cut part through and then brake off the part along the cutting. This works only for simple shapes with straight edges and not too small parts.
 
 
 

As set of doors (ca. 11 mm high) cut from 0.1 mm bakelite paper
 
White polystyrene is too reflective and is only lightly engraved, if at all. I did not have black polystyrene at hand to try this out.
 
I would abstain from cutting PVC due to the generation of toxic and corrosive combustion products.
 
I have not tried ABS or Lexan, but would expect similar issues as for polystyrene.
 
Celluloid might cut well, if you have a coloured variety. Transparent celluloid, including drafting films such as Ultraphane, will not work. The high flammability of celluloid may be an issue.
 
White paper works moderately well due to its high reflectivity. An important factor is also its weighing and seizing. Weighing with barite or titanium oxide makes it more difficult to cut, as both materials are refractory. A seizing with glue or plastic polymers increases the volumetric density and therefore make the paper more difficult to cut.
Coloured papers and cardboard work best, but thicknesses above 0.5 mm become more difficult to cut. The deeper the cut the more charring of the edges will occur, loosing precision in size and reducing the minimum size of features that can be cut.
I have not had the opportunity to cut wood, but I would expect that low-density woods cut better and then hardwoods. The size limitations are likely to be similar to those of cardboard.
 
Cork should cut reasonably well, but I have not tried it myself.
 
 
Drafting for cutting
 
As for any other ‘machining’ operation, the ‘tool’ diameter is an important consideration. The effective diameter of the well-focused laser-beam is in the order of 0.1 mm. These leads to the rounding of internal corners in this order of magnitude, but the actual rounding depends also on the size of the opening to be cut. Smaller openings may have a more perceptible rounding than larger ones.
In practice, the charring of the edges leads to slightly larger openings than those drawn. Thus the diameter of e.g. holes needs to be drawn 0.1 mm less than required. Similarly, slots should be chosen 0.1 mm narrower than the nominal width.
The laser sends a pulse for each black pixel encountered. When converting vector drawings into bit images, the question arises of the actual size of the parts that appear white in the final image to be used in the laser-cutter. This may depend on the line thickness chosen and the kind of drafting program. I found that I needed to experiment with the cutting parameters (power setting and contrast) and in some cases needed to redraft (parts of) the drawings in order to arrive at the correct size. Several iterations may be needed to arrive at the correct size. This also depends on the material, thicker material requiring more adjustments.
Every part that is black in the drawing will be burned. In order to reduce the laser time and the fumes generated, it is good practice to fill in any empty space. While this would be good practice in photo-etching too in order to safe etching fluid, often this is not done. However, when converting drawings for laser-cutting it is a good idea to fill in the empty spaces.
I use a 2D CAD system for drafting (EazyDraw™). This program allows the drawing to be exported into picture formats such as JPG. The resolution for this step has to be chosen so that the final part has the correct size for a resolution of 512 dpi or 202 pixels per centimetre. This means that a part that is 1 cm long should be 202 pixels wide in the JPG etc. file. In order to reduce the area to be burned, I usually import the image into Adobe Photoshop Elements™ and whiten all the respective areas. Sometimes is also convenient to draw the parts in solid black, which then necessitates their inversion in Photoshop. I typically export the drawings at 1024 dpi and then reduce the image in Photoshop to the desired width in the number of pixels as calculated for 512 dpi after the post-processing has been done. This allows me to ascertain that the drawing has the desired size. In this way it is also easy to produce cutting designs in various scales from the original drawing.
As the cutting happens on a flat surface and there is no mechanical interaction with the material, the cut pieces do not move from their place during the cutting process. Therefore, retaining tabs, as you would need in photo-etching, are not needed and the parts can be completely cut out. This avoids the problem of distortion during separation from the fret, particularly of very small parts.
 
 

A typical JPG-image as used for the cutting process (size around 35 mm x 30 mm)
 
 
 
Safety
 
Lasers are dangerous for the eyes and you are advised to consult the respective guidance on laser safety.
The laser-cutter comes with a green protective glass on one side. I also bought a pair of green safety-glasses for adjusting the laser focus, as viewing the focal point through the shielding glass is inconvenient.
The combustion fumes of certain materials can be a nuisance, noxious, or carcinogenic. In any case they are smelly. As noted above, it is wise to reduce the areas to be burned in order to minimise the amount of combustion products. For certain materials some kind of forced aeration may be needed, or you need to set up the laser-cutter outside.
Some materials may also be a fire hazard. However, none of the materials I worked with seem to have been problematic in this sense. There would not be enough mass to sustain a serious fire, but a fire-proof base is important.
In any case: never leave the machine running unobserved !
On the Internet you can see people, who have encased their cutters and added forced ventilation to it. Whether such arrangement is warranted, depends really on how intensively you use it. In my case it just runs occasionally for a few minutes at a time.
 
 
Conclusions
 
This technique cannot fully replace photo-etching to produce small, complex and delicate parts, but is is a versatile ad hoc option requiring little preparation in comparison. The cost of materials is minimal and therefore that of trial and error. There are no chemicals to manage safely, but fumes can be an issue.
There is no equivalent to the ‘surface etching’ process, parts are strictly two-dimensional. As in photo-etching, there is, however, the possibility to build up parts from several layers.
Metal surfaces and its edges can be made very smooth. Achieving the same effect with paper or cardboard is difficult, even when treated with wood-filler to produce some sort of compound material that can be sanded. In some applications that surface roughness does not matter or may be even desirable.
The mechanical resolution of 512 dpi and the diameter of 0.1 mm of the laser-beam impose limitations to the minimum size of parts that can be produced. Laser-cutting with such small desk-top machine cannot compete with commercial etching processes using high-resolution masks.
In scratch-building, when parts need to be developed as the building goes on this kind of laser-cutting certainly is a useful ad hoc and flexible process.

It's coming on nicely. Somehow, the boat looks, as if mixes 19th and 18th century features, the bow looks still quite 18th century in shape.

A systematic approach always helps !

Gary, Keith, thank you! I hope to extend the enjoyment of viewing the pictures a little.   

Yes, Lou, I understand you.
I am very pleased that my work brings so many positive emotions!    

Good job on something, that can go easily wrong in different !
 
Yes, Christmas will be rather different this year, with no family gatherings in many parts of the world - even when legally possible, one should refrain anyway, as the whole society will pay for it in the end. We normally travel to Germany to spend Christmas with relatives, including my 95 year old mother - we wouldn't even get there, let alone be allowed to visit her ... very sad.

Before continuing with this build article I would like to review some of what I've learned, and how it affects the work as it progresses. First of all I have learned that I need to soak/saturate the card stock from packaging much better. Originally I only used multiple painted coats of thinned poly varnish to do this work. I was only saturating the uncolored side, which is in effect sealed off by the printing. I have since learned to sand the colored side of the card stock, using 320 grit sandpaper and a small wood block, to roughen up the surface and remove as much of the sealed surface as possible. The second thing I've learned is to use a small plastic tray, in my case the base of a plastic container used locally to hold bakery goods, to literally soak the stock for at least five minutes. This worked much better at hardening and saturating the card stock. It makes it slightly more difficult to cut out parts, but keeps the fraying from unsaturated inner parts of the stock down to a minimum.
            Although not evident from the photos shown thus far, the hull does have some places where the top of the bulwarks are not symmetrical side-to-side. One side has a slight bulge and the other a bit too much tumblehome inwards. I believe this is due to the fact that I did not cut the slots for the individual pieces well enough, in some places the bulkheads were not perfectly 90 degrees from the keel piece. I didn't realize the problems this would cause later. I figured that although the center keel piece was forced out of alignment at the deck level, once the tops of the bulkhead pieces were glued to the spacer piece it would straighten out. I was wrong, the top of the center keel piece was pushed sideways slightly in places, but I could not see this until the hull was planked and cut from the spacer piece so I could view that area.
            As a lot of the work involved soaking or gluing, and then waiting for up to 24 hours to continue work, I decided to see if I could improve on the hull by starting over completely. Remember, this whole things is an experiment to see what is possible and what can go wrong and how to improve things with card/paper modeling. I am still working with the original hull,  as experimenting with it will help improve things overall.
            I redesigned the bulkheads and added some additional pieces to make what I believe will be a stronger and better hull. The following images show this new design.

            Like the previous plan drawings my CAD program exports rather poor images, I have all these drawings as PDF drawings if anyone is interested. The major changes to these plans are the additional longitudinal stiffeners and the open areas on most bulkheads at deck level. I am hoping that it makes cutting down to deck level much easier and more accurate. I also extended the bulkheads on each side right at the top of the bulwarks line, to make planking in that area much more accurate.
            I did make up the parts for the new hull, using the above mentioned soaking technique to the card stock this time. While the results were much better overall, it was a bit more difficult to cut the thoroughly saturated stock not to mention a lot more slot cuts were needed. The following images show some of the work on cutting out and gluing together that different parts. Each was made twice, and then each pair glued together to make up the final pieces.
 

 
            After the pieces were glued together to make up the hull parts, I dry fit each piece to all the pieces it would interact with in the final hull form. I made sure each piece fit easily and the pieces remained square to each other. It took a lot of time, and if a piece fit tight enough but slightly off square I would slightly enlarge the slot so that it would be square. Slightly over sized slots turned out not to be a problem, as there are so many pieces that fit together it did straighten it all out.
            The installation of the longitudinal pieces did require them to be installed on all the bulkheads that they interacted with at one time. And, due to the limited open areas above the deck level, they had to be put in place at 90 degrees to their final position. They were then slid into place and rotated to fit into their respective slots. A bit fiddly to do, but it worked out quite well due to the dry fitting and trimming of all the slots.
            The hull parts were put together in sub-assemblies, which were then added to the center keel piece. The larger center section had to be added first, then the stern and bow areas added. The following photos show this work.
 

 
            All the joints were then glued with white glue. This hull form was very stable. This time I glued the spacer print directly to a 3/8" maple board, and glued the tops of the bulkheads to that. Unlike the first hull, this time all the bulkheads lined up perfectly on the spacer print, with no adjustments needed. The following photo shows the final results of this process.
 
Anchor's A Weigh!
John Fox III

Thanks everyone for your feedback and likes!   
The final appearance of the capstan after plating with nickel in an electroplating bath.

Good morning and thanks to all, I take this opportunity to wish all the modelers of the forum Merry Christmas and Happy New Year.
Yes Robert, do you have any pictures of your xebec?
More photos.
 
 

 

 

 

 

 
Un Saluto.

Good morning and thank you all for the likes, more photos....
 
 

 

 


 

 

 
Un Saluto.

Good job on something, that can go easily wrong in different !
 
Yes, Christmas will be rather different this year, with no family gatherings in many parts of the world - even when legally possible, one should refrain anyway, as the whole society will pay for it in the end. We normally travel to Germany to spend Christmas with relatives, including my 95 year old mother - we wouldn't even get there, let alone be allowed to visit her ... very sad.

Just running a couple of ropes across a boat sitting upright on chocks may not be sufficient to keep the boat from rocking. Today, so-called gripes are used, these are hooks that go over the wales and have an eye at the end. A rope is reefed in several turns through this eye and an eye-bolt or something suitable on the deck or the chocks. This rope then is fastened on itself after hauling it taut. Instead of hook, this rope could also be fastened to a suitable structural member inside the boat. The idea is to secure the boat at four points, rather than just pulling it down onto the chocks.
 
Small boats that are relatively easily man-handled may be also better stored upside-down to keep them dry and to prevent overcoming water to collect in them in making them top-heavy.

Thanks Phil!   My work is progressing.

There has been a 1:100 scale (sorry metric ...) model of the GERMANIA by a German modeller:
 
https://www.arbeitskreis-historischer-schiffbau.de/mitglieder/modelle/germania3/
 

It may be worthwhile asking on what drawings his model was built. Keith, if you want, I can contact him and ask. He lives in Spain and specialises in models of such yachts.

Just running a couple of ropes across a boat sitting upright on chocks may not be sufficient to keep the boat from rocking. Today, so-called gripes are used, these are hooks that go over the wales and have an eye at the end. A rope is reefed in several turns through this eye and an eye-bolt or something suitable on the deck or the chocks. This rope then is fastened on itself after hauling it taut. Instead of hook, this rope could also be fastened to a suitable structural member inside the boat. The idea is to secure the boat at four points, rather than just pulling it down onto the chocks.
 
Small boats that are relatively easily man-handled may be also better stored upside-down to keep them dry and to prevent overcoming water to collect in them in making them top-heavy.

I think the model in the link above is one I seem to remember, not the 'seaman's' style one.

Thanks for the comments everyone!  Lots of good discussion and information provided, too.  Can't ask for more than that!
 
Today was decal day.  Decided to name the boat "Roisin Dubh (pronounced "Ro-sheen Dove").  It means "black rose" and was the title of an Irish political song from the 16th century, according to Wikipedia.
 
After spraying a gloss coat all over the boat (in part to protect the paint but mostly to prepare the surface for decals), I used individual-letter decals from "Microscale."  These letters are made for model railroads, and the font is called "Ornate."  The gloss coat was "Pledge Acrylic Floor Wax" sprayed on with an airbrush and allowed to dry overnight.
 
You will also notice the rivets on the chainplates.  This is also a decal product for modelers from "Archer Fine Transfers" (http://www.archertransfers.com).  They are little drops of resin on clear decal sheet.  Three dimensional decals!  They can be cut out in strips and applied quickly, or you can muddle along with individual rivets.  I used the strip method.  Usually, I apply them before painting, but these are not yet painted.  I'll do that after they set, really well.

It's these little, often overlooked details that bring life to a model ...

Further work on the hull
 
The bulwark in the aft part of the hull is supported by a number of stanchions that were cut from sheet metal and rivetted together. The looks for these stanchions is reasonably well documented on a number of photographs.
 

The aft part of a WESPE-Class-Boat (Lavverenz, 1900)
 
The stanchions I had drawn already years ago and depicted the rivetting by surface-etching. The material is 0.1 mm thick nickel silver. They were made in double as mirror images and soft-soldered together in pairs with soldering paste so that the rivetting appears on both sides.
 

Etched and soldered together stanchions (they are about 5.5 mm high)
 
The location of the stanchions was marked on the bulwark before this was put into place by thermo-transfer of a drawing, i.e. a laserprinter printout was ironed on. The stanchions were cemented in place with fast-dryining varnish.
 

The bulwark-stanchions in place
 
Already a short while ago I had fashioned the boiler-ash chutes by milling to shape little blocks of acrylic glass. They were cemented to the bulwark inside and outside at this stage too.
 
To be continued ...