wefalck

The machine-files come in various shapes and sizes, therefore, various holders to hold them securly and parallel to the axis of movement had to be designed. I opted for sockets into which bushings for the various file sizes will fit. Additional bushing were made to hold fine jewelers saws, so that the machine can also be used as fret-saw. Cross-drilling the file-holder during construction The holders to attach onto the driving piston and the guiding piston in the overam were turned from steel. The holders were tapped M3 for two set-screws on opposite sides that will act directly on the files. Cross-drilling bushings for various files The bushings were turned from aluminium with a selection of internal diameters to fit the available files. They were then cross-drilled to allow the set-screws in the holders to pass through. In fact, the holder on the driving piston has two sets of set-screws set 90° apart in order to allow the orientation of triangular and rectangular files as needed. The collection of bushings The guiding piston had a 8 mm x 1 mm thread cut on the watchmakers lathe, as I had a suitable tap for this M8 (fine) thread. Two thumb-nuts with this thread were machined from aluminium (to keep the mass of the guiding piston low). They will give a coil-spring around the piston the necessary intial tension. It is necessary to keep the very thin (1 mm diameter) files under tension in order to prevent them from buckling during the up-stroke. Lower and upper file-holder together with guiding piston To be continued ...

I like this idea of using small ball-bearings as hold-downs and may adapt it to one of my machines

Indeed many bench lathes, including those for modellers, such as the Unimat, had saw-tables as an option. For added precision the saw-arbors we countersunk at the end, so that they could be supported by the tailstock. However, when sawing a lot of wood, I would be cautious with all the sawdust around that it doesn't get into the spindle bearings. Also sawdust and oil makes mixtures that stick to leadscrews and can lead to excessive wear, particular when metal chips are mixed in as well.

Thank you … at my pace it will still take a while ... ***************************** The original drive-shaft was made from a steel of rather poor machineability. It was impossible to achieve a satisfactory surface finish on it with the watchmaker's lathe. As I intended to change the original design slightly anyway, a new drive-shaft was turned from a piece of 32 mm round steel. This shaft was bored out for the 6 mm diameter gear-box output shaft to which it will be attached with a set-screw. Original drive-shaft and crank New drive shaft/crank, cross-head, bearing block, and piston The whole crank mechanism was also replaced, as it was badly worn due to steel-on-steel sliding friction without any lubrication. Originally a round pin was sliding in the cross-head slot. The new design provides for more positive guidance. A proper cross-head bearing block was machined from brass and will slide in a new cross-head. Assembled new drive shaft/crank, cross-head, bearing block, and piston The new crank was bored for the cross-head pin at different distances from the axis, which allows to set the stroke of the machine at 10 mm, 15 mm, and 20 mm. However, it will be necessary to almost dismantle the whole driving mechanism to change the stroke, as the set-screws for the cross-head pin would not be very accessible. The maximum stroke of 20 mm may not be possible with the current file-holder design due to sufficient clearance under the table, when it is inclined. Practical experience will show, whether a 15 mm stroke is satisfactory. New drive mechanism (provisionally) in place To be continued ...

As can be seen on the photograph showing the disassembled jigsaw, the piston for the saw-blade was guided by two self-aligning bearings. These bearings essentially were two cast-iron spheres set into slots and that were bored for the steel piston of 9.5 mm diameter (3/8”). Self-aligning bearings in the original jig-saw Lubrication relied on the self-lubrication of the graphite in the cast iron and the system had already considerable play in consequence. Therefore, the spheres were bored out to accept 10 mm self-lubricating bushings for 8 mm rods. These came from China through a well-known Internet service and are presumably normally used in computer printers and the like. Self-lubriacting bushings were chosen, because oiling would have been difficult under operating conditions. The new piston was fashioned from 8 mm polished and calibrated silver steel. Bored out bearings with new self-lubricating bushings in place To be continued ...

I would tend to agree with you concerning level of detail and scale - but: unfortunately, unlike in a photographic image, the viewing distance is not fixed. Though in general, one may view a model from, say, half a metre or a metre distance, one may also put the nose over it. If I were to design a model, for instance, as a film prop and it would only be seen from a certain distance, I would indeed put the level of detail on it that is needed to give the 'right' impression. For a show-case model the situation is rather different. Here you need to create the 'right' impression for various viewing distances. For certain details it may be safer to err on the small side ...

I would suspect that Downton-pumps were fitted. These come in many varieties, here is an example from the preserved 1840s Portuguese Frigate: In later years they were also made with cast-iron bodies. I don't have British drawings, I believe, but I think some French and German ones. I would have to check in my library.

De gustibus et coloribus non est disputandum ...

I would like to add to my above post that one has to try to avoid being merely 'additive', which is why the first image in the previous post looks rather cluttered. Details have to blend into the overall image. On the other hand, the two images above do not compare very well with respective to what they were meant to show, because they portray two different subjects from two different periods. The first image seems to show an urban setting from the 1930s, while second image seems to show a more rural modern setting. Since the 1950s you can generally observe a de-cluttering of our (i.e. Western World) land- and townscapes. Simpler lines on everything, plain concrete walls, etc. So there is less 'detail'. The same applies to modern ships compared to e.g. the old sailing ships. Modern ships are mainly welded, while older iron- and steel-ships would have been rivetted, which immediately makes them look more detailed (even when countersunk rivetts were used). So, if you want a realistic appearance as they may have looked at their time, you may to include a lot of clutter and details (as in the first image above). Conversely, if you want to point out the aesthetics of hull lines or of the sail-plan, you may want not to include such detail.

Dealing with the restoration of antique watchmaking machinery, I came across some pretty odd threads, but they seem to have been somehow standardised, as they re-occur in various machines. Modern engineering handbooks are largely useless to identify such threads. Finally, I got hold of a 657 page book from 1924 that only deals with threads. The multitude of threads that were used in different industries before Whitworth and SI (DIN/ISO norms) is quite amazing. The book also has a section on watch industry threads. It appears that each major factory has (had) its own standards ! However, in the Swiss watch industry the so-called Thury-thread seems to have become prevalent. Here is a Web-site with some information on it and dimensions: http://sizes.com/tools/thread_thury.htm. Chances are that these screwcutting plates that are being sold by watchmakers supply houses (and on eBay) have Thury threads. Proper taps and dies (as opposed to the plates) are made down to 0.2 mm diameter, I believe. I have some down to 0.3 mm, but would use them only on my watchmakers lathe, to ensure absolute concentricity and no side forces in order reduce the risk of breaking them. A die cost about 15 EUR in the late 1990s, when I bought them. Taps are cheaper.

I gather, a real mechanic would throw up his hands into the air, if he sees me working …. ************************** The next part to be tackled was the socket for the overam holder. An overam is needed for guiding the delicate machine files and for taking up the side pressure when filing. The foot for the sawing table on the casting was hollow and sort of house-shaped inside. A piece of aluminium bar was carefully milled to shape and size to provide a snug fit. Two tapped holes will locate it in place. Shop-made boring bar with collet to fit the milling machine Boring-out the hole for the overam upright Drilling the 10 mm hole for upright round bar proved to be taxing for the capacity of my machines. There was not enough clearance under the mill for such large-size drill. Due to the hole being in one end of the part, it would also not fit into the four-jaw chuck for boring out. In the end, I realised a long-planned project and made an adjustable boring bar from a piece of 8 mm rod. For this I also had to fashion a collet with three set-screws for 8 mm bars etc. With this boring bar it was easy to drill out the hole with an excellent surface finish. Overam holding socket Overamr holding sockt in place To be continued ...

If you go to location 52°33'07.02" N 4°36'10.96" E in GoogleEarth, you will see just a beach off Castricum in the Netherlands. However, when you switch to the 2005 image, you will see the ghost of S.M.S. SALAMANDER, which was an armoured gunboat of 1872 of the Imperial German Navy. She sank there in a storm in 1919 being towed to the Netherlands to be broken up. The shifting sands now seem to have covered her remains that were still visible in 2006 at very low tide. At some stage attempts were made to salvage and restore her, but it proved to difficult and costly. S.M.S. SALAMANDER was one of the boats of the WESPE-Class, the prototype of which I am currently building: http://www.maritima-et-mechanika.org/maritime/models/wespe/wespeclass.html (see also the building log on the forum).

Thanks for the praise to all I think there are numerous tutorials on the Web on photoetching, Matie. I am using pre-prepared brass sheets available from various vendors. In order to keep things simple I work with small frets only and use small vessels, such as plastic film containers, for the processes. Compared to professional foam-etched parts, my shop-products are not that well-defined at all. It is not so easy to agitate the parts in the etching solution sufficiently uniformly. In fact, I produced probably two bad parts for every good one. In the end I picked the best parts from all tries. Surface etching (e.g. rivets) is simple, you just need two different masks for both sides. As you can see from the pictures in the post above, one mask just covers the areas not to be etched-away, namely the rivets and other raised features.

Well, too much travelling the last few weeks resulted in little progress. It is frightening to think I started this project already in March, thinking that I would quickly return to my WESPE-class gun-boat project … ****** The excentric rod was turned from a piece of steel, while the actual lever with the ball end is a recovered piece from a similar broken commercial product. For other pieces of equipment I turned such levers myself using a ball-turning attachment. Method for turning the excentric for the holding-down bolt Holding- down bolt and excentric lever assembly Table bearing barrel and locking arrangement To be continued ...

Hi Mark, I have been tossing with the idea of getting one of these cheapo units, but your experience really put me off becoming an 'early adopter'. There is a lot of potential in laser-cutting, but as with every tool you get what you pay for. Also this experience seems to confirm the wisdom that these Chinese machines (whether manufactured to foreign specs or direct imports) should be rather considered an assembly of parts in an advanced state of machining … a starting point for a project I may come back to this, when my eye-sight gets too bad for working on small parts - hopefully in another couple of decades or so.

Traditionally, brass and silver are protected from oxidation by applying a coat of cellulose nitrate (collodium) dissolved in amylacetate, ethanol and ethylacetate. In Germany such lacquers are known under the name Zaponlack and can be bought as commercial formulations from D.I.Y. stores.

Ship models are usually kept indoors, so there is not really a need for preservation or stabilisation. There may be issues with woodworms (anobium punctatum), but this is a long-term preservation issue. In some parts of the World you may be also worried about termites, I gather. Otherwise, the surface of wood is usually treated for esthetic reasons mainly. Covering the surface with some sort of lacquer or varnish also allows for easier cleaning, which again may not be an issue for a ship model that is kept best under a glass cover anyway. Outdoor wood preserving agents that contain various organic or inorganic biocides would actually be most unsuitable for indoor use because they may give of hazardous fumes or may be toxic when people/pets come into contact with them. For the same reason, one should not (re-)use such wood (e.g. old railway sleepers etc.) indoors.

For straight cuts in brass up to 0.5 mm thick I would score it with a cutter about half-way through (as noted above) and then wiggle it (perhaps with a pair of flat pliers in the case of narrow strips) until it breaks off. The edge, of course, needs to be filed or sanded flat. Thicker stuff I run through the table saw or the saw table on my watchmakers' lathe with a HSS sawblade. This leaves a very clean cut. Curved cuts in very thin brass, say 0.2 mm thick, can be done with an inverted saw blade in a a jewellers' piercing saw. In this way the teeth will not 'catch', as otherwise there may be only one tooth in contact with the material at any one time.

For me there is only one rule: reproduce the prototype as well as you can within the limits of materials' sizes and their workability (and of course your skills). Detail only appears too much and overcrowding, if they are done overscale (for whatever materials or skills reasons). The conclusion from this could well be not to include a certain detail, because it cannot be reproduced adequately.

Good point, thibaultron, about the hand-files that are cut for the push stroke, while machine files have a socket at both ends, but normally are inserted in such way, that they cut on the down-stroke of the machine. I also acquired a couple of diamond-studded stub-files with prismatic resp. cylindrical cross-section for use in filing machines; the obviously cut in both directions. ***************** The lathe-turned part for the bearing-barrel was sawn in half and the two halfs were clamped end on in the vice after careful alignment. With a fly-cutter the surface was milled perfectly flat and the diameter reduced to bring the rotational axis of the table into its surface. Milling flat the halves of the bearing-barrel The position for the barrel was marked out on the piece of 4 mm aluminium that will become the table. In the following step the positions for the mounting screws were marked out and drilled mit a 3 mm drill on the drill press. The two half-barrels then were stuck onto the table with a few drops of cyanoacrylate glue after careful alignment. Bearing-barrel in position on the underside of the filing-table The positions for the mounting screws then were marked with a transfer-punch. A light knock separated the parts again, which were then transfered to the mill for drilling and tapping M3 of the mounting holes. I usually start the tap on the mill with a few turns to ensure it is perfectly concentric to the hole and vertical. The tapping is completed by hand. Drilling and tapping the mounting holes for the table on the bearing-barrel Sqaring the edges of the aluminium plate for the filing-table proved to be just at the edge of the capacity of the milling machine. The plate was clamped to the vice on the mill with a C-clamp and the edges milled flat. Squaring the edges of the filing-table With the bearing-barrel screwed onto the underside of the table, the assembly was bolted to the table of the milling machine for milling the slot for the holding-down bolt. This holding down-bolt will be tightened using a excentric lever. Milling the slot for the holding-down bolt To be continued ...

Actually, as the sail would be put together from its panels etc. you don't need any pencil lines and the likes. The seams would show up as on the prototype by the shadow of the edge of the panel or doubling.

Is the work done already ? If not, why not using very thin polystyrol sheet ? This would save you also the filling and rubbing down to get a smooth surface. Otherwise, I would use liquid plastic cement for glueing paper strips. This seeps into the paper and dissolves the polystyrol of your hull, forming a solid bond. You can apply more cement afterwards as a filler, before sanding the strips.

Not sure, why everyone wants stitched sails. The stitching and the thread used are grossly out of scale unless you work in say 1:24 or bigger. However, glueing the panels together is an option. Not sure the glue on the tape would be strong enough for the narrow seams in the sails. It is meant for full-surface re-enforcement in picture-mounting and book-binding.

If you are using brass throughout, a good base may be chemical tinning. I cannot recommend a reagent source for this in US though. After thorough cleaning and degreasing (as you would do for blackening) you immerse the parts in the solution until a coating has formed. Initially the coating is of a dull silver, which looks quite like galvanised steel. You can touch up places also with paint as noted above. Rubbing a soft lead pencil over areas that would show wear makes it look more like bare steel.

You may also want to have a look her at post no. 39ff: http://modelshipworld.com/index.php/topic/68-zuiderzee-botter-by-wefalck-artitec-resin/?p=53698, leading to the final product: