SMS WESPE 1876 by wefalck – 1/160 scale - Armored Gunboat of the Imperial German Navy - as first commissioned

[wefalck]

Cog, resin-casting requires a model, a prototype. If I can make one, I can make four without too much effort. So, not much is gained. The difficulty is making the 'model'

 

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Steering-wheels, third edition

 

A colleague challenged me to turn the brass reenforcement rings. I took up the challenge and bored out a piece of round brass stock to 6.8 mm and turned down the outside to 7.2 mm. From this tube with 0.3 mm wall thickness slices of 0.1 mm thickness were parted off. After a few trials to get the settings right this worked fast and repeteable. The rings were deburred on 600 grit wet-and-dry paper, ground finely on an Arkansa-stone and polished on a piece of paper with some polishing compound.

 

The new steering-wheels, above the brass rings

 

As it would have been very difficult to remove the old rings from paper from the wheels, I used the opportunity to produce a third edition of the wheels in which I left out one of the middle layers. The second edition was actually slightly too thick. Using the tried-out cutting parameters and now with some practice in assembling them, the new wheels were ready soon. The brass rings were glued on with lacquer.

The freshly cut wheels (I use a roof slate as cutting support)

 

The axle including drum for the steering rope were turned from brass.

 

A pair of steering-wheels provisionally assembled and the component parts

 

The wheels will be spray-painted painted all over and then the paint rubbed off from the brass rings. This will nicely simulate the rings let into the wood as per prototype.

 

To be continued ... hopefully soon ...

Edited January 28, 2020 by wefalck

[KeithAug]

Nicely done Eberhard.

[BANYAN]

Very nice Eberhard, practice makes perfect!

 

cheers

 

Pat

[wefalck]

Thank you very much, gentlemen 

😇

 

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Steering-stands

 

The steering-stands consists of two pillars supporting a pair of wheels. These pillars were somehow bolted to the deck, but drawings and photographs do not show how it was done. On the model this detail will be barely visible, as the lower part of the columns will be hidden by the gratings platform.

The grating actually were photo-etched a long time ago. However, I did not like the rounded-out corners, which are due to my somewhat primitive etching process. Therefore, I cut the gratings also with the laser from Canson-paper. By playing around with the settings of the laser-cutter, I managed to produce reasonably square field and sharp corners. The fields resp. the ‘laths’ are only 0.3 mm wide and the grating is 0.3 mm thick (0.3 mm in 1:160 scale is equivalent to just under 50 mm for the prototype). I would have found it impossible to produce a grating in these dimensions prototype fashion.

 

Steering-stand gratings: JPG-image as input for the laser-cutter

 

The gratings are made up from two layers of paper 0.15 mm thick each. Imitating the prototype to some degree the lower layer only had transversal laths. Both layers were glued together with lacquer. The transversal reenforcing bars are built up from three layers of paper and glued to the gratings again with lacquer.

 

The platforms are raised above the deck by four short columns that were turned from brass rod. They were slotted for the reenforcing bars on the micro-mill.

 

The steering-wheel pillars were designed on the basis of the photographie showen earlier and what can be deducted from the lithographs. There is a pole protruding from the front pillar of the stand on the bridge, the function of which is unclear to me. It may have supported an indicator for the rudder or just the lanyard for the steam-pipe. The only known photograph that shows a boat before the armoured command tower was installed is too grainy from the printing grid (it is only known from a publication) to allow to discern such details.

 

Steering-wheel pillars: JPG-image as input for the laser-cutter

 

The pillars where built up from three layers of Canson-paer, which allowed to represent the cannelures. The pillar appears to be rather thin, but this is how it is drawn on the lithograph.

 

The axle of the steering-wheel rests in bearings that are clad in brass or bronze. A piece of 2 mm brass rod was bored out for the round heads of the pillars and then a thin disc was parted off. For further machining the discs were held in special insert collets with a low recess turned into the front (so-calle jewelling collets, used by watchmakers to machine watch jewels or bushings).

 

Machining the bearing caps in a 'jewelling' collet

 

The profile on the front was turned with a small boring tool and the dome-shaped cap over the axle was formed with a cup burr, as used by jewellery-makers to round off wires.

 

Shaping the covering cap of the wheel-axle using a cup burr

 

The caps are actually only segments of a disc and were milled of on the micro-mill accordingly.

 

Milling of the segment-shaped caps

 

All parts were glued together using lacquer

The individual parts of the steering-stands

 

Steering-stand on the bridge loosely assembled (a 1 €-cent coin for reference)

 

To be continued ...

Edited February 4, 2020 by wefalck

[michael mott]

Remarkable work Eberhard!

 

Michael

[BANYAN]

Remarkable indeed, especially at that scale.  Very nice detail achieved in something so small.

 

cheers

 

Pat

Edited February 7, 2020 by BANYAN

[KeithAug]

Very nicely done Eberhard. Excellent detail noting the small scale that you are working at.

[wefalck]

Thank you ! Trying to do my best to keep up with you guys

 

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Freeing Ports

 

Originally I had planned to surface-etch the lids and the frames on the inside of the bulwark. The drawings for the masks were ready, but I never got around to actually etch or have the parts etched. Since I now have the laser-cutter, these parts were cut from printer-paper (80 g/m2 = 0.1 mm thick). With a width of the frames of only 0.5 mm, the surface-etched rivets may not have come out anyway. The same for the rivets on the hinges of the lids. At least not with my somewhat primitve home-etching arrangement. If I had etched the parts from 0.1 mm nickel-brass, the overall thickness would have been reduced to a more correct 0.05 mm (= 8 mm for the prototype).

 

The lids have no latches to lock them and the ports no bars across them to prevent items or people being washed over board. This makes their construction simpler.

 

Papers, even the smoothest ones, alway have a certain surface-roughness, at least compared to the bakelite of the bulwark. Therefore, the chosen paper was soaked in wood filler and spread to dry on a thick glass-plate that was covered in cling-film. The latter allowed to remove the paper without it rolling up. The surface was then smoothed with very fine steel-wool. The lids were cut from the thus prepared paper, but it needed several trials to find the right cutting parameters in order to arrive at parts of the correct dimensions. This is a disadvantage of such simple laser-cutters and their software. As the material is practically free, this is only a nuisance, but no other loss. Also the etching may not work out right in the first go, which may mean a considerable loss of money and time, if the process had been outsourced.

 

Laser-cut lids for the freeing-ports

 

Unfortunately, it does not work for very small parts with the paper prepared as above. It turned out to better for the very small parts, including the frames, to cut them from unprepared paper. Perhaps I should switch to dark paper. Due to its lower albedo (reflectivity) it absorbs more energy from the laser. Unfortunately, all the coloured papers I have come by so far are quite rough on the surface.

 

I cheated somewhat for the freeing-ports. As I was afraid that I would not been able to cut them out cleanly and evenly, I abstained from it. Also, the bakelite-paper used for the bulwark for reasons of stability would have had a scale-thickness of 64 mm, when looked on from the side. Therefore, frames and lids were glued flat onto the inside and outside of the bulwark respectively. I hope one will not notice this too much, once the stanchions are in as well.

 

Frames and lids were glued on with zapon-lacquer. Little laser-cut rectangles of 0.3 mm x 0.5 mm were stuck onto lids to simulate the hinges.

 

Installation of frames and lids 

 

To be continued ...

Edited February 9, 2020 by wefalck

[KeithAug]

Very neatly done Eberhard. I am surprised that the designers decided they needed so many ports, do you know why?

[wefalck]

Thanks, Keith.

 

These boats were designed to have a very low profile, as kind of difficult to spot and hit mobile gun-platform particularly in the wadden seas off the German coast. The main deck was only about 1 m above the CWL, so they had a very low freeboard. They must have been very wet in anything but calm weather. I guess that's it, why there are so many freeing-ports.

[Bedford]

I can see the logic in that design but pity the poor deck crew having wet feet all the time.

 

Beautiful work as usual.

[BANYAN]

Very nice work Eberhard; they came up very well indeed as the inner and outer alignment appear 'perfect'.  What is the masking film you have used as the straight/levelling edge please?

 

cheers

 

Pat

Edited February 9, 2020 by BANYAN

[wefalck]

Pat, that's just ordinary 'invisible', i.e. mat, cello-tape. Plus, as I  had put the pattern onto the bakelite paper using thermo-transfer (ironing-on a laser-printer printout), alignment was easy.

[mtaylor]

Eberhard,

Check a stationary store for cardstock.  I've seen some very smooth and very thin stock in assorted colors.   

[wefalck]

Mark,

I have raided indeed all major art materials stores here in Paris and the huge art and architecture materials department store in Berlin. Thin and very smooth seem to be two demands that are not so easy to satisfy at the same time. As I will apply sanding filler either before or after cutting, I might get away with a somewhat rougher material. There are many 80 g/m2 coloured papers for fancy letter writing. As the parts are going to be painted anyway, the colour-fastness of the paper per se is not of relevance.

 

Logically, less glued papers are easier to cut with the laser, as the pulp burns away quickly, while the glues may require more energy and any refactory additives such as baryte or TiO2 are counterproductive. That is why the shiny magazine papers don't work so well.

 

 

[Baker]

Very detailed work on this small scale

magnificent !!

[wefalck]

Thank you !

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Doors in the foredeck and the decks house

 

Foredeck and decks-house were accessible through various doors. These were cut from 0.1 mm bakelite paper with the laser-cutter. The hinges were laser-cut from thin paper. In both cases various tries were needed with different cutting parameters and slightly altered drawings in order to arrive at the correct size. Die parts were assembled using zapon-lacquer. Zapon-lacquer was also used to glue the door into place.

 

Laser-cut doors from bakelite paper before clean-up 

 

On historical photographs I noticed that each door had a narrow step. These were represented by shaped and laser-cut tiny strips of paper.

 

View of deck-house and back of the fore-deck with the doors installed

 

Once the door were in place the hole for the bullseyes were drilled out. The laser-cut hole served as a guide. Once the boat is painted, the glazing will be installed in form of short lengths of 1 mm Plexiglas rods. The front of the rods will be faced and polished carefully on the lathe.

At a later moment also the door-knobs will be turned from brass and installed.

P.S. Apologies for the somewhat poor quality of the photographs, but I have been too lazy to take out the SLR camera and took them with the telephone.

 

To be continued ...

 

Edited February 20, 2020 by wefalck

[KeithAug]

Eberhard - very fine work as usual. I will be interested in your perspex polishing technique when the time comes.

[wefalck]

Thanks, Keith. Way back in post #32 I am making cores for skylights from Plexiglas and discuss the techniques.

 

It is straightforward: you just have to face off the rod with a very sharp tool, then, if really needed, I smooth with a very fine 'rouge' paper attached to a flat surface (kind of emery file, but with 'rouge' paper), holding it flat to avoid rounding the edges; finally I use a tiny blob of metal polishing cream on a folded piece of toilet paper.

[druxey]

Lovely work as usual. What is the advantage of using Bakelite paper, please?

[wefalck]

Druxey, this material is much harder then styrene and files/sands well. However, it is also more brittle and sawing has to be done with caution. Sheets of up to 0.5 mm thickness can be scored with a scalpel and then broken for straight cuts. Unlike thin metal sheet it doesn‘t dent, but is as smooth as metal without preparation.

 I would perhaps prefer acrylic glass, but that is not available down to 0.1 mm thickness. Acrylic would glue better. However, I found that the bakelite glues well with CA - I clinker-planked a little boat with it some 25 years ago and it does not show any signs of deterioration. The glueing with laquer is likely to hold up well too, as the lacquer is known to be very stable.

The bakelite paper also paints well with acrylics without any special preparation.

Edited February 21, 2020 by wefalck

[druxey]

Thanks for the explanation, Eberhard. Now I wonder if mica is also a possible material to work with....

[wefalck]

Mica is a layered silicate. There are two varieties the light coloured muscovite and the dark biotite. The silicone dioxide molecules are sort of arranged in tretraeders that form layers along which the mineral cleaves very well. To the contrary, the layers hold together very well and are rather stiff. Hence one cannot bend the mineral and it break easily.

 

Traditionally, muscovite was used in some parts of the world, including Russia and notably Moscow, hence the name, to glaze windows. As it breaks less easily than glass it was used on ships. It still is used due to its temperature resistance to cover peeping holes in furnaces.

 

I don't think it would be very suitable for modelling except for glazing windows and lamps.

[druxey]

I've only used mica for miniature glazing, Eberhard. I was simply musing....

[SJSoane]

Exquisite machining, craftsmanship. I think I need a more powerful magnifying visor; you are working at exceptionally small tolerances!

 

Mark

[BANYAN]

Ditto on the compliments Eberhard; just back with my new PC and catching up.  Very nice workmanship as usual.

 

cheers

 

Pat

[wefalck]

Thanks, gentlemen ! The work continues:

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The lower carriage of the 30.5 cm gun

 

The lower carriage of the gun was a rather complex construction from rolled L-profiles and thick steel sheet. Unfortunately only the drawings in GALSTER (1885) and the coloured synoptic drawing from the Admiralty have come to us. Many construction details are superimposed onto each other with dashed lines, so that the interpretation of the drawings is rather difficult in places. As aids to interpretation with have one close-up photograph, the large demonstration model in the navy museum in Copenhagen, and the preserved guns of Suomenlinna Fortress off Helsinki. The carriage for the Danish iron-clad HELGOLAND, however, differs from that of SMS WESPE in some details, being actually a turret-carriage. The carriages in Suomenlinna are Russian copies of Krupp fortress carriages, but they allow to verify certain construction details that are not clear from the drawings.

 

Synoptic drawing of the 30.5 cm gun (from http://www.dreadnoughtproject.org/)

 

Originally I had planned to construct the lower carriage, like the upper carriage, from surface-etched brass parts. To this end I produced some time ago already the needed detail drawings. Surface etching is a very good process to simulate rivetting. In the meantime, however, I had purchased the laser-cutter, so that laser-cut parts would be an alternative. I had hoped to cut the parts from bakelite paper. Various trials with different cutting parameters unfortunately were not very successfull for the intricate parts. The 5 mW laser ist too weak to burn the material fast enough. Burrs of molten and partially carbonised resin form. Therefore, I fell back onto Canson-paper, which is a bit over scale with its thickness of 0.15 mm.

 

Base-plate and races laser-cut from Canson-paper

 

The drawings for the etching masks had to be reworked for laser cutting. It turned out during assembly that I had made several mistakes or misinterpretations. If I had send them off for etching this would have been costly, as both masks and etching would have to be redone. When cutting paper with a laser such corrections can be made quickly and easily – and the material costs practically nothing.

 

The basic frame of the lower carriage from the rear

 

The laser-cut parts were soaked in nitrocellulose wood-filler and once dry rubbed with very fine steel wool. To double up parts and for assembly zapon lacquer was used. This dries so fast that no special arrangements for fixing the parts are needed.

 

The basic frame of the lower carriage from the front

 

I did not take pictures of the different steps of assembly, as this would have rather impeded the process. First all parts to be doubled up were cemented together using zapon lacquer and weighed down to keep them flat during drying. The longitudinal parts of the carriage had slots cut into them, so that the transveral parts could be positioned exactly. The frame assembly then was cemented to the base plate (which in reality was not a plate, but rather the frame was put together from L-profiles and steel sheets). The racers, again in one piece, where glued on top of this assembly. Underneath the base plate the housing for the training gears (which will be very much simplified as they will be barely visible upon completion of the model).

 

The basic frame of the lower carriage from underneath with the housing for the training gears

 

One can see on the laser-cut parts marks for the rivets. These will be added as tiny spots of white glue. More details will be added in the next steps, but have not all been drawn yet.

 

 

The basis frame of the lower carriage with the upper carriage and the gun put temporarily in place

 

To be continued ...

Edited March 8, 2020 by wefalck

[KeithAug]

Very interesting Eberhard, I particularly liked the simplicity of the human powered rotation and elevation gear below deck. Do you know how many crew were needed to man the gun?

[wefalck]

The man-powered training gear was actually quite sophisticated with the gun-captain being able to turn the gun left or right with a lever without the men needing to change the direction of cranking. I don't know how many were needed, but one can estimate the number from the length of the cranks. I will have to measure it.

[KeithAug]

1 hour ago, wefalck said:

but one can estimate the number from the length of the cranks

Yes I was wondering if it required 4 per crank handle - 2 in front and 2 behind.