wefalck

Thanks, Pat ... but close-up photographs are really unforgiving, as one can also see in the following ...
 
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Further work on the lower carriage
 
Back to the lower carriage. The (mor or less) central pivot determines its rotational axis, but the weight of the gun is actually supported by four (kind of) caster wheels running on cast-iron rails bolted to the bottom of the barbette.
The rails had been turned already a long time ago. The forks for the caster-wheels were fabricated from laser-cut cardboard. The wheels themselves are simple turned steel discs with a groove.
 

Caster wheels prepared for assembly
 
For the assembly, the rails were taped down onto an appropriately scaled print-out of the original plan of the vessel and carriage fixed with a clothes pin. The wheels and forks are temporarly united by axels made from short lengths of copper wire. The casters then were cemented under the carriage in the correct position with respect to both, the rails and the carriage frame, using again varnish.
 

Caster wheels in place
 
The wheels will have to be removed again before painting the carriage, because they will be left in bright steel. I do not know, whether this is correct for the flanges of the wheels, but it gives the whole arrangement are rather ‘technical’ look. The axles with cylindrical end-caps have already been prepared from steel rod and will be installed during the final assembly.
 

Caster wheels in place
 
To be continued ...
 

Thanks, gentlemen, for your kind words ...
 
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Scrollwork and name-plates
 
As I had tried laser-engraving on cardboard for the gun-layer stand, I wanted to try out this technique also for the scrollwork and the name-plates. Originally, I had foreseen to develop the scrollwork by printing the design onto a decal-sheet and then build it up by sculpting it over the printed lines with acrylic gel. The name-plates could have been surface-etched in brass. One could have etched, of course also the scrollwork in brass and then complete it with acrylic gel.
 

Best available image of the bow scrollwork and name-plate
 
It is not very clear what the scrollwork looked like when new and from what material it was made. The fact that it seems to have persisted intact over the whole life of these ships may indicate that it was actually cast in some metal, rather than carved in wood.
There are no close-up photographs of sufficient resolution in the black-white-yellow paint-scheme. Closer photographs are only available from a later period, when everything was painted over in grey and some of scrollwork may have been picked out in a darker grey. Originally it was probably painted in yellow-ochre with parts of gilded. In any case, available photographs are not clear enough to truly reconstract the scrollwork, so some interpretation was necessary.
In addition to the scrollwork per se, there was a shallow sculpture of the animal after which the ship was named, for SMS WESPE, of course, a wasp. Existing photographs only give a vague idea what these sculptures really looked like. In any case not for SMS WESPE.
 

Only available image of the stern scrollwork
 
There has also been some scrollwork at the stern, but pictorial evidence for this is rather scarce. There is only one known photograph that gives a full view of the stern of this class of ships and this was taken at the very end of their service life. Available copies of this photograph are not clear enough to really discern what the scrollwork actually looked like, so a fair amount of imagination is needed to recreate it.
 

Artwork for the bow scrollwork
 
Creating the basic artwork for the decoration was a multiple-step process. First a photograph of the respective section of the model as built was taken in order to give the necessary proportions. In the next step the best available photograph with the least perspective distortions was chosen and fitted over the model photograph. In another layer of the graphics software (Graphic for iPad) the scrolls were drawn free-hand (with the iPen) using the paintbrush-function and a good amount of smoothing. This artwork was saved as a JPEG. On the Internet I found a nice drawing of a wasp and turned this into a pure b/w image with a good bit of editing in Photoshop. Both, the scrollwork and the wasp were saved as transparent GIF. In my favourite CAD-program (EazyDraw), the parts were mounted together. This could have been done also in Photoshop, but I did have a scaled drawing of the bow-section in EazyDraw to which I exactly fitted the artwork. There were also some addtional parts to be cut.

Some examples of the (unused) laser-cut scrollwork and the name-plates
 
The scrollwork was cut/engraved with the laser-cutter using the ‘half-tone’ function, which means that the laser is modulated to emit less power when a grey pixel is encountered and full power, when a black pixel is encountered. I had to play in several iterations with the settings of the laser-cutter in order to arrive at a satisfactory result.
 

Scrollwork and name-plate in place
 
In a first try the name-boards were made in the same way, but the half-depth engraving around the letters resulted in a somewhat fuzzy apearance of the letters. I, therefore, tried out a different idea. From previous trials it was know that the laser had no effect on transparent materials and very limited effect on translucent materials. Hence, I covered some cardboard with a thin layer of Pleximon 192 (essentially liquid, light-hardening Plexiglas). A thorough curing this sandwich was sanded flat and presented to the laser-cutter. The laser removes all the cardboard, but leaves the acrylic virtually untouched, with the exception of some light surface roughness. One ends up with a piece of thin acrylic sheet to which the letters and the scrollwork of the name-board are attached. Within the limits of the resolution (0.05 mm) of the laser-cutter the lettering turned out reasonably clear, perhaps not as crisp, as when photoetched though.
 

Stern scrollwork in place
 
The scrollwork elements were attached to the hull using fast-drying varnish. The actual painting and guilding will be done, once the hull has been painted.
 
 
To be continued ...

Folding tool update
 
After the first use of the tool, I immediately made a couple of modifications, which however, I had expected to introduce anyway.
When working with cardboard or paper one needs to ‘overbend’ the folds somewhat, so that they stay at the desired angle. This is different to working with soft sheet-metal. Styrene sheet also will have this spring effect. Therefore, the folding edges were given a 10° clearance angle. An angle of 15° may have been even better, but it works with the 10°. The edges are not really weakened by this.
The second modification was to place a spring washer under the folding ruler. I had in mind to do this right away, but could not find them in the first place. The washers lift up the ruler a bit, so that it is easier to slip the material under it.
 
 
Gun operating platforms and gratings
 
The gun is mounted effectively on a turntable, so that platforms for crew are needed to give them access to the gun, while is being trained left or right. These platforms are made of wire gratings that are placed into angle-iron frames. The frames are suspended from the lower carriage by brackets. The pictorial evidence (photographs, drawings) is not detailed enough to fully understand what the brackets actually looked like and how and where exactly they were attached to the lower carriage frame. Some additional information is given by the Danish instruction model and the Russian clones in Suomenlinna fortress, but the carriages of these guns differ in detail from that on SMS WESPE. So the reconstruction of these platforms remains somewhat conjectural.
 

Crew standing on the gratings and operating the gun
 
 

Gratings of the Danish instruction model
 
 

Detail of gratings on a gun in Suomenlinna fortress
 
There are 13 gratings and steps in total, plus the platform for the gun-layer. The original plan was to photo-etch the frames from brass sheet, but with the arrival of the laser-cutter I changed this plan. The drawings were modified accordingly. The obvious solution to simulate the angle-iron frame was to design an open frame and then fold-up the vertical parts of the angle. However, it proved impossible to fold the narrow, 0.3 to 0.4 mm strips consistently and without distortions. Not sure this would have worked with the PE parts either. It was then decided to make the open frame and the vertical parts separately as narrow strips and glue them together with lacquer. After several iterations of drawings and laser-cutter settings to arrive a workable width of the strips etc. I arrived at an acceptable solution, albeit the ‘angle-irons’ are somewhat over-scale.
 

 
Example of a drawing for the gratings and their supporting brackets
 
Assembly was a slow and nerve-wracking process. I did not manage to do more than one grating per evening and it involved a lot of (mental) foul language. Eventually, I got them all together. Zapon-varnish was used throughout the assembly. The finished parts are surprisingly strong.
 

First Version with engraved surfaces of the platform for the gun-layer
 

Final Version of the platform for the gun-layer (5 mm grid on the cutting-mat)
 
The original plan was to simulate the wire-mesh of the gratings by real wire-mesh and I obtained from wires.co.uk some really fine mesh in brass and steel. The idea was to pull every second wire in one direction, as the original mesh was rectangular. It proved, however, very difficult to cut such small pieces (sometimes only 1.5 mm wide) from the wire-mesh. Then a present to wife in form of a box with various (fruit) teas came to my rescue: some of the teas came in bags made from extremely fine but lightly woven fabric. I do not know what material it is, but as it dissolves in acetone, it is probably cellulose acetate silk or Rayon. Such fabrics are also used in silk-screen printing and I had not chanced upon the tea-bags, I would have looked there. This silk-screen or fabric can be precisely and easily cut with a new scalpel blade. The small pieces of fabric were dropped into the frames and fixed at the edges with a light touch of varnish.
 

Tea-bag fabric
 
The platform for the gun-layer is a more complex structure. A 5 mm sheet-metal armour shield is meant to protect him from shrapnel and small-arms fire. The armour shield is reinforced at the edges with rivetted-on metal strips. The original plan was to produce this as a surface-etched part. I realised that the laser-cutter interprets half-tone images as instructions to modulate the laser power so that it does not cut all the way through. Laser-engraving in other words. It did produce the desired effect, albeit with the engraved surface being rather rough due to the digitising effect. However, this part then was so thin and flimsy, that it would not stay in shape, when attempting to shape the round corner. I reluctantly accepted that it would be somewhat over-scale in thickness and cut the armour shield and the reinforcing strips separately. They were glued on top of each other with varnish and then the round of the shield formed over a rod. Folding and gluing completed the process.
 

The collection of gratings and steps
 
I am not entirely happy with the result and tend to think, that etched parts may have looked finer. But then their assembly would have required a lot of very delicate soldering work – I don’t trust CA for metal/metal bonds too much. On the other hand, attaching the gratings to the lower carriage frame is likely to be easier for the cardboard parts than for brass parts. Before that can be done, I need to add the wheels, which requires a lot of handling ...
 
To be continued ...

Thanks, gentlemen, much appreciated !
 
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Folding tool


 
As will be seen in the next post, quite a number of delicate laser-cut parts will need to be folded. Therefore, I thought a folding tool might come handy. A number of commercial gadgets are available, but considering that they essentially consist of a couple of milled-to shape pieces of aluminium and a thumb-screw, I find them rather overpriced at €20 to €70, depending on what you buy where. Also, if I have the right materials and tools, I prefer to make such things myself.

I did not have a suitable piece of flat aluminium in stock, so I decided to make it from some 4 mm thick Plexiglas off-cut. This has the added value that you can better see, where you place the folding edge. Plexiglas is more vulnerable than aluminium, but I can always make a replacement, should the need arise.



 
A set of fingers ranging from 1 mm to 6 mm width were separated by notches made with a 4 mm cutter. The front was bevelled for better access to small parts. The opposite side was left straight for longer parts. For the moment, the front edges where milled at 90° degrees, but I can imagine that a slight overbending would be better. I am considering to mill on a 5° or 10° relief angle, but will first test the piece in practice. A more acute angle will make the edges more vulnerable to chipping. The underside is somewhat recessed over most of the width, so that tool really clamps with the front edge, where it is needed, and does not wobble.







As I also did not have material for a base in stock, I decided to use the base of the sanding tool that I made a while ago. It has the added value that no extra gadget is floating around the workshop. The folding ruler was drilled and two corresponding holes in the base were drilled and tapped for M3 thumb-screws.
 
 

Loading crane
 
Somehow I seem to move two steps forward and then one step back again. For one part completed there are several that jump off the table to be never found again or that are destroyed during subsequent steps of manipulation ...
Mechanically, the loading crane is a relatively simple affair, a rope winding drum driven through a pinion and cog-wheel, powered by a hand-crank, and for turning a worm-wheel drive equally powerd by a hand-crank. The console on which the crane rests is a quite complex part that was bolted together from several cast parts.

The loading crane on the demonstration model in the former Naval Museum in Copenhagen
 

The winding mechanism of the charging crane
 
My first thought was to mill the console from the solid or rather to solder it together from several milled parts. I finally decided to put the laser-cutter to work and fabricate it from several cardboard pieces. On the bottom line, this was the easiest solution and compatible with the rest of the under-carriage
The crane on the demonstration model in Copenhagen mainly consists of bright pieces of steel or cast-iron. Whether this was the case too originally on the prototype cannot be verified anymore, as no detail photographs exist. It is perhaps doubtful due to the continuous maintenance required to keep rust at bay. Although, the navy was not concerned about camouflage at that time, they were aware of the risk of early detection by the enemy due to bright metal part reflecting the sun. However, I allowed myself the artisanal-aesthetic license of bright metal, as I think it will be a nice contrast to the dark green of the gun carriage later.
The actual crane was milled from a 2.5 mm steel rod. To this end the thickness profiles in both dimensions were taken off the original drawings and ‚stretched’ out straight in the CAD software. After milling, the part was softened in the flame, so that it could be bent according to the drawing. The hole and slot for the pulley were machined afterwards, as the part could break there during bending. The final shaping was done with silicone-bound grinding bits.
 

Milling of the crane in the dividing apparatus
 
 
Pulleys and forks form them are tiny parts machined on the lathe and the milling machine.

Fork for the lower guiding pulley
 
The mechanism of the crane consists of a good dozen of lathe-turned parts, that were, apart from their minute size, were not particularly challenging.
The cog-wheel, the pinion, and the worm-wheel were turned together with their axes in one piece. On the photographs I counted 60 teeth on the large wheel, which gives, together with a diameter of 3 mm a module of 0.05. Making a single tooth mill seem to be too much work, so that I took the short-cut of just gashing the wheels with a 0.1 mm thick circular saw. It is only about the look and I did not intend to make these gears functional. Hobbing a worm-wheel of just 1 mm diameter was too big of a challenge, big of a challenge, but at least I tilted the axis 20° when gashing it.
 

 

 

Milling of the pinion and the cog-wheel
 



Partly assembled loading crane
 
The final assembly can only be done, once the crane-console has been attached to the carriage and the whole thing is painted.
 
 
To be continued ...

Thanks !
 
I am actually a Geologist ...

Your wife is a sedimentologist or hydraulics engineer ?
 
I've tried to recreate a similar situation, albeit for a tidal harbour, using some real silt/mud, for a ship sitting on a 'grid', they had in some tidal harbour for iron ships:
 

For the moment, I had no need to use it for that purpose, but some years ago I bought a hot-air soldering station. The temperature can be regulated between 100°C and 450°C and the air-flow can also be regulated. It comes with different size nozzles and cost under 40€ including shipping from China.
 
As heat is the main ingredient in plank-bending (the steam mainly serves as heat carrier ...) I would make myself a jig to fix the planks while cooling down. With the temperature and air-flow control and a small nozzle it may be even possible to heat the planks in situ on the model, but beware that you do not loosen previously glue planks. The in situ method might be useful for compound curves.
 
If you want to know what is really possible in terms of wood-bending, look up Thonet-furniture (their famous No. 14 chair is the classical bistro-chair). They used mainly beech, I think, and massive cast-iron jigs to hold the shape, while the wood was cooling down:
 
 
Also note the use of steel strips to distribute the bending forces and prevent kinking.

Yes, the sails look very good. Remind me, what you did in the end and what scale the model is in.

If you have an baking oven that can produce 800°C, you will be ok ... just joking. No, you would need a furnace or a blow-torch to heat the steel to a light red glow in order to obtain the oxidation layer. Most bearing balls are just polished, not chromed, but there are also hard-chromed varieties. The are made from steel alloys that give them high hardness, i.e. they contain chrome and/or nickel or other metals. Depending on the composition, there is a trade-off between corrosion reistance and hardness.
 
Certain steel can be blackened by heating them with vegetable oils until the oil burns off. This has been largely replaced today by chemical blackening. Blackening (as blueing or browining) is a chemical reaction of the steel with different types of metal salts. In general, corrosion resistant steel are more difficult or impossible to blacken. Chrome-plated steel doesn't blacken.

This looks a bit like a high-tech operating theatre 
 
The swing-through cradle with integrated gantry drilling-jig is an excellent idea !

Yes, the sails look very good. Remind me, what you did in the end and what scale the model is in.

Just a note that I finished the man-of-war. These are the results:

Not very spectacular from the side view.
 


The quarter views are OK though.
 

And the sails look like sails. I'm a happy man.
 
Ab

If you have an baking oven that can produce 800°C, you will be ok ... just joking. No, you would need a furnace or a blow-torch to heat the steel to a light red glow in order to obtain the oxidation layer. Most bearing balls are just polished, not chromed, but there are also hard-chromed varieties. The are made from steel alloys that give them high hardness, i.e. they contain chrome and/or nickel or other metals. Depending on the composition, there is a trade-off between corrosion reistance and hardness.
 
Certain steel can be blackened by heating them with vegetable oils until the oil burns off. This has been largely replaced today by chemical blackening. Blackening (as blueing or browining) is a chemical reaction of the steel with different types of metal salts. In general, corrosion resistant steel are more difficult or impossible to blacken. Chrome-plated steel doesn't blacken.

Thanks for mentioning Kemmis' book, I wasn't aware of it. Just downloaded it now from GoogleBooks.

Yep, looking better 👍
 
As I noted earlier, I think, playing with the different levels of sheen between the different materials adds visual interest and underlines the character of the material, particularly, when you simulate material with paint. In a 2D-painting you bring out these effects with high-lights and painted-in reflections, but on a 3D-object the view-point and illumination changes, plus the inherent reflectivity of the surfaces, so one can really only work with this reflectivity to create the feeling for the material. Figure-painters to some degree use both techniques, but it does not work so well on larger objects.

This is acrylics on polystyrene. No wood involved here ...

Sorry to say, but decks were always matt, as they were always bare, untreated wood that more or less regularly scrubbed with a piece of sandstone ('holy stone') .... but it is your choice.

Yep, looking better 👍
 
As I noted earlier, I think, playing with the different levels of sheen between the different materials adds visual interest and underlines the character of the material, particularly, when you simulate material with paint. In a 2D-painting you bring out these effects with high-lights and painted-in reflections, but on a 3D-object the view-point and illumination changes, plus the inherent reflectivity of the surfaces, so one can really only work with this reflectivity to create the feeling for the material. Figure-painters to some degree use both techniques, but it does not work so well on larger objects.

OK wefalck, the deck is now matt. Have to admit I do like it better. 

 
 

Thanks for mentioning Kemmis' book, I wasn't aware of it. Just downloaded it now from GoogleBooks.

Perhaps one could/should look also how such connection would have been done in real life. I gather this is a pump(-spill) related connection rod and cross-head ? Then the bolt with a cylindrical or semi-circular head would be either threaded at the other end and a sequence of a washer, a nut and a locking-nut would be screwed on, or, more commonly, the bolt would have a square slot; a washer would be put on and then a metal wedge would be inserted. Hexagonal nuts are easy to file from either thick-walled tube or drilled-out round brass rod. Washers can be produced with a hollow punch from styrene sheet or paper/cardboard. A wedge can be simulated by a tiny piece of styrene sheet. For the bolt I would use a brass or copper pin, but give it a more defined shape in an electrical drill.
 
BTW, I would also file away the flash from the cast white-metal parts and straighten them a bit.

Good morning and thank you all, this is the system I used.
 

 

 

 

 

 

 

 









 
Un Saluto

The ship was apostrophed as 'motonavi per linee minori', which means 'motorships for minor shipping lines'. That 'motonavi' is plural may indicate that this plan pertain to a class of ships, rather to specific one.

The ship was apostrophed as 'motonavi per linee minori', which means 'motorships for minor shipping lines'. That 'motonavi' is plural may indicate that this plan pertain to a class of ships, rather to specific one.