wefalck

Gloves on a lathe are an absolute no-no. Many fingers got ripped off, because the glove got caught in a chuck etc. Don't underestimate the power of even small hobby lathes. An old engineer's trick is to use a piece of cardboard as fixed steady. If you have a fixed steady, you can attach the cardboard to this. If you don't you make one yourself e.g. with some pieces of wood. As the makeshift steadies are easy to make and cheap, you may have even several of them for very thin parts. In the old days lathes also often had a steady that formed a kind of frame (as in a slide projector) into which two pieces of wood or cardboard could be slid, one below and one above the work piece. Both parts had a half-round hole of the approximate diameter of the workpiece cut in. The parts could be clamped in the frame.

Such small chain would be difficult to find ... I found that chain, at least in small scales, can be reasonably well simulated by twisting two wires together, but not too tightly. Two lengths of such wire are then again twisted together against the original direction. This will looks reasonably convincing like a somewhat twisted chain.

How would you shift ballast at sea ? It would be nearly impossible to get to it, given that the cargo usually was wedged in order to prevent it from moving around. This would require to open the carefully closed hatches at sea too - the hatches were covered by (double) layers of tarpaulin, nailed down in order to provide a water-tight closure. The only access to the holds were the very small cargo hatches. There would be also no space, except the limited deck space, to store loads while re-arranging the hold ... this is different from warships, where more intermediate deck space was available and stores were taken out of the hold regularly. There the cooper would collapse barrels etc. cautiously for later re-assembly and re-use. In the tea-loading ports there were experts that would carefully stow the boxes according to size and value (the most valuable in areas the least likely to be exposed to damage by water). The boxes were litterally hammered into place, I seem to have read in one of the books cited above. No chance to get them out at sea. This tight storage on commercial ships made fires in the hold so dreaded. Very difficult to get access.

London has become a rather desolate place from the maritime history point of view ... but we are getting off topic here.

And I know someone, who hasn't set his foot again into the Science Museum since ...

There are whole books on ship stability, performance and loading. Just a few additional observations: - the behaviour in sea of a ship depends on how far the centre of gravity of the ballast plus load is below the centre of gravity of the hull; the lower the stable the ship is, but also stiffer, i.e. it works harder in the sea and more strain is put on the rig. - the ship designer strived to keep the wetted surface (up to a point) and the hull speed more or less the same at all angles of heeling in order ensure equal performance. - the loading of the ship was the responsibility of the captain and perhaps the suprecargo; until the later 19th Century there were no obligatory rules for the remaining freeboard (although there has been 'Lloyds Rule' since the 1830s) and the Plimsoll Mark was not introduced compulsary until the end of the century; the captain would also decide by his experience with the ship on the trim, i.e. the difference in draught forward and aft; the trim influence the maneurvrability under sail and the performance when heeling. - load, centres of gravity and trim are only one set of parametres that determine the overall performance of a ship in the sense of the duration of passages; a keep variable here are the experience, knowlege and intuition of the captain that lets him choose the right route at the right time of the year; there are many examples for (theoretically) slower ships to make shorter passages; the books by Lubbock for instance are full of such stories.

From an economical perspective, commercial sailing ships used two types of ballast, the one that was permanently required to make the ship stable and the other to make up for a lack of cargo in order to keep it stable. The room in the hold is valuable, so you would keep the amount of ballast to a minimum. Some traders got away with no or little balast, while others, such as the tea-clippers needed lots of it, but could justify the loss of cargo space due to the high price the commodity they were transporting would fetch. An important consideration for balasting was the availability of the respective material, its cost and also how easy it could be brought on board or discharged again. Sand was a cheap temporary option in many regions, but you ran the risk that the pumps got clogged. Harbours usually had an area, where sand-ballast was allowed to be thrown over board. Violation of these rules could entail hefty fines in some harbours, as it could lead to silting up the harbour. Whenever possible, the temporary ballast was some material that could be sold at the destination harbour, so being something like a high-density, but comparatively low value cargo. I have two examples: - many houses in the Caribbean are built from bricks that came from Europe as ballast; on the (formerly Danish) US Virgin Island these are called 'Flensborg Stone', after the town of Flensburg in Germany, which belonged in personal-union of the reigning house in the 18th and 19th century to Denmark (until 1864); there were many brick-factories around the Baltic coast in this area. - the streets of most towns around the southern Baltic coast are paved with big slabs of igneus rocks (e.g. granite), which came from Scandinavia in the timber ships to counteract inter alia the deck-loads of timber.

Of course it is wonderful to watch a skilful craftsman at work and a job well executed probably gives these craftsmen great job-satisfaction. However, what counts in the real world is the quality of the result, how much time is needed to arrive there and how much it costs. Modern technology allows us to produce intricate parts that would be very difficult, if not impossible to make with traditional tools and methods. Perhaps I could have made these steering-wheels as a sandwich of five or ten on my filing machine, but even the finest and smallest commercially available files (and I have these) may have been to coarse. My original intention was to use photoetching, but this is always a very complex procedure, when you cannot have it set up permanently somewhere - not really an ad hoc useable tool. Perhaps CNC-milling would be an alternative too, but here you always have the problem of rounded corners due to the practical limitations of tool size, which is probably 0.3 mm diameter, compared to the 0.1 mm for the laser-point. I was aware of the limitations of this lasercutter before I made the decision to go for it. Unfortunately, I don't have the space for a bigger and more powerful machine. Apart from the cutting-speed, I am not so sure that tracing a vector-drawing gives really a better end-result. The slightly jagged edges would more or less remain due to the motion of the stepper-motors. They might become somewhat more smoothed out though due to the fact that the laser would remain powered during the movement. As the laser-dot is twice the size of the steps, a certain smoothing already occurs.

Somehow these struts appear to be an afterthought, when they discovered that the upper part of the bulwark and the rails were too weak ... they neither look terribly nice, nor is their presence safe. On the other hand, when you look at racing pictures, you see the crew kind of sliding down to the lee rails, so perhaps these struts also provide something to hold onto.

Well, you may have noticed that these seem to be the 'balanced' variety: they are pivoted in the upper third, so that the lower part swings outward and the upper part inward - where some seem to collide with a strut. There more traditional ones indeed are hinged along their top edge, but this means that you can see the hinge from the outside, which may not be desirable on a yacht.

How true, I know someone very guilty of looking for complicated solutions ... 😊 BTW, I was wondering how these rotating freeing-ports would work, when there is a strut in their way. They would not be able to turn very much.

Way back in the early 1980s I used to program in BASIC, including driving a plotter. However, I think, technology has moved on since and didn't quite keep up with it From what I read diagonally, it should be possible to drive the laser-cutter from vector graphics, but for the moment, I don't really want to get into technology development. Producing parts is the call of the day, in order to get the SMS WESPE project finished - I have been on it now for 13 years, believe it or not ... I have been too often side-tracked by making tools.

Thank you very much for the kind words ! ******************************************** There are some really delicate parts lined up now, such as the frames for the freeing ports along the bulwarks. My original thought was to have them photoetched from 0.1 mm brass. However, given the difficulties I had in creating good, dense etching masks, I thought of trying a different route and something that is less messy. Laser-cutting seemed to be an interesting proposition. So I got myself a new little toy at 100€ incl. shipping. Toy is perhaps an adequate description for these small compact machines that are now on the market. Their design-purpose probably is to mark merchandise with a burnt-in logo etc. For this reason they are mobile, so items of any size can be marked by just putting the little (15 cm x 15 cm x 15 cm) box on them. Their power is limited, 3W. A mechanical resolution of 0.05 mm is claimed, with a diameter of the laser-spot of 0.1 mm. The engraving area is 53 mm by 53 mm. The software driver works by converting the images into bit-maps and then it runs them down line by line. I should try to find another driver that uses vector graphics, which would speed up the cutting process presumably. KKMoon-Lasercutter with a 3W laserdiode The software allows to adjust various parameters, including the contrast of the image, the power output of the LED, and something called ‘cutting depth’, though it is not clear what the latter really does. The focus of the LED can be adjusted manually to allow for materials of different thickness, but it is difficult to judge, whether really the minimum of the spot-size has been achieved. Given the power of only 3W, there are limitation to what materials can be worked with. The cutting resp. engraving effect depends on how much energy is needed to burn or vaporise the material. Paper works well, but a 0.4 mm cardboard seems to be the limit. I did not have much success with white styrene, only some light surface marks resulted even at the highest settings. Hard paper (phenolic resin impregnated paper) would have been my favourite material, but apart from the strong smell (the fumes are also not terribly healthy) a 0.2 mm thick sheet was only cut half-way through. Semi-transparent tracing paper does not take up enough of the energy and remains untouched. A sufficient optical density is required in order to absorb the energy and burn/evaporate the material. Strangely enough, the laser left quite visible marks on the piece of roof-slate that I used as fire-proof protection under machine. Converting a drawing into a cut-out piece is not quite straightforward. I first had to work out a way to scale the bit-map and JPEG images that I created from my CAD-drawings. The solution was to draw a box around the graphics to be exported, measure this box and then to scale the exported drawing in Adobe Photoshop to a number of pixels the resulted in the box of being of the desired size when laser-cut. The resulting scaling factor was 1 mm = 20 pixel, which was indeed the claimed resolution of 0.05 mm. On an image everything that is black will be burned away and everything white will remain. However, simply converting the CAD-drawings into images resulted in too narrow/small parts due to the fact, that the each burnt point has a diameter of at least 0.1 mm. Therefore, it was necessary to adjust the sizes of the areas to be burned away so that the remaining parts have the desired dimensions. The effect depends on the burning parameters and on the material. So, unfortunately, each new material and new part will require a certain amount of trial and error. I tried my luck on another set of very delicate parts, namely the steering-wheels. They have an OD of just under 12 mm. Turning the complex shape of spokes of 6 mm length appeared to be daunting task, even if one could have perhaps made the handles and the spokes themselves in two parts. The laser-cut ones look quite good after a few trial runs, but I have to see, whether I can build up enough thickness from several layers. Cutting them from 0.4 mm thick cardboard was not fully successful. Laser-cut steering wheels of 12 mm outer diameter I just wanted to share the first experiences with this new workshop toy and trials will continue. To be continued soon(?) ...

Normally, (some) maritime knots are designed to allow exactly that, to tie them while the corresponding rope is under tension. So choosing the right knot is the key. In many cases no knots are used to attach ropes, but rather lashings. Running rigging is 'belayed', which involves a sort of temporary knot. So, tightening involves loosenings the lashings or the belayed ropes. I would recommend that you get hold of a modern book on tying knots for yachtsmen, which explaines the basics that would be valid for at least the past 200 to 300 years.

No problem from my IP address in France ...

When I see the acreage and the barn-sized shed and then read the word 'down-sizing', what should I say with a 2 m by 2 m workshop-corner in my study/office ... ? BTW, someone above suggested to put the flooring around cupboard to save flooring material. Not sure that is terribly wise, because you may want to have floor-insulation all the way through and perhaps the flexibility to move cupboard etc. around, if the original design turns out to be not so handy.

My knowledge of shipbuilding practice in the 17th Century is close to nil. However, looking at sketch B above, it appears to be that a simple triangular chock would be forced inwards on any bending movement of the futtocks. This would constitute an inherent contructional weakness. When the chocks have shoulder, the bending movement of the futtocks would compress the chocks on the shoulders. Similarly, that sort of scarph in sketch C would lock the two parts of the futtocks together, thus reducing somewhat the squeezing-out effect on the chock. Mechanically, the solution C seems to be even better than A, as the outsides of the futtocks are locked together.

I know, some people use this material, most notably 'Doris' and Ab Hoving, but one has to remember that soft plastics, such as vinyl, will become brittle with age due to the plasticisers gassing out.

There could be other practical reasons: stowed sails, when humid, will rot, or when trying to shake out frozen sails, they may break ...

I am still wondering what, objectively speaking, the purpose of the sealing is ? Unless it is an operational model, there is not really a need to toughen the surface.

They look good indeed - apart from the price: six hooks for USD5 plus shipping 😳 I wonder, how they achieve the rounded effect, etching and then sandblasting ?

Well, that's a difficult thing to say. I gather, I have always been drawn to intricate things, in museums to the small highly-detailed models. Of course, I admired the big (board-room) models with their metal-work etc., but knew that I would have never the space for such a project - I hate giving away models, so I need to find the space to keep them. My first ('semi-scratch') model was in a 1:60 scale and then I continued in the same scale with the following scratch-built project. Then I realised that this was an unusual scale - it would have been better to go for 1:72 or something like that. Large scales, of course, are much more impressive for the casual observers. At some stage, I decided to go for scales in which figurines from the railway-community would be available, here on the European continent these are 1:87 (HO-scale) and 1:160 (N-scale), HO-scale for small boats and N-scale for larger vessels. The kind of limiting criterion was, that the overall drawing should fit onto an A4-sized paper. The challenge at these scales is not so much the machining as such (large-scale models could have also very small and intricate parts), but the availability of suitable raw materials. There is a limit down to which you can get wires, sheet-metal or -plastic or paper, or threads for making ropes. Sometimes also it would be geometrically possible to machine the parts, but the material just becomes to flimsy at small dimensions. Of course, it would be nice to also have larger machines - particularly for making attachments for the smaller machines However, my 'carreer' involved moving every few years, so I decided to keep my workshop mobile in the sense that the machines can be easily dismantled and crated or packed. The smaller watchmakers lathes come in fitted boxes anyway and for the milling machines I made solid crates. The appartment we will be retiring to in a few years time hopefully will have dedicated (small) workshop cum display room, but somehow my wife still tries to convince me that I won't really need it, as we would be out in street-cafés anyway, as the locals do in southern Europe ...

Future and similar 'self-shining' floor products are essentially dispersions of acrylic resins. So they are safe to use on acrylic paints. The curing of acrylic paints is a mixed process of forming cross-links of the dispersed acrylic resins and dewatering. The dewatering is a relatively slow process based on diffusion. This is why acrylic paints dry up rather fast, but stay somewhat soft for a considerable amount of time. When you apply a relatively thick layer of varnish (e.g. 'Future') over a relatively thick layer of acrylic paint, the latter will be prevented from diffusing out the water. In other words, the varnish might cure faster than the paint, resulting in shrivelling and cracking of the paint underneath. The same can happen, when you apply layers of oil-paint too early onto acrylic paint. Spray-painting of several thin layers of acrylics with some time between coats, give the paint enough time to cure thoroughly.

I am geochemist with many years of experience at the lab-bench ... on my work-bench there are no potentially corrosive chemicals, only paints and organic solvents (denatured alcohol, acetone, white spirit). When pickling or like processes are to be done, then away from the work-bench and near somewhere, where the parts can be thoroughly rinsed. Never use any cleaning 'products' of unknown composition on a model itself. It will be very difficult to remove any residues and they may creep into joints etc., where they can create havoc over the years. On copper I only use fine steel-wool and acetone. Don't use 'kitchen recipes' for patination etc. They may give more or less the desired effect, but it is important to create a stable patina that does not continue to eat into your metal or react with other components of your model. There are handbooks on patination/browning/blackening for metal workers, sculptors and the likes. Follow their procedures and recommended materials.

In Germany we used the funnel-pens directly with the templates. The templates had sort of rails above and below, which lifted them a bit above the paper and also allowed them to be aligned precisely on the horizontal ruler of your drawing machine. There is an ISO/DIN norm for the lettering and this standard lettering was mandatory for technical drawings. I think this 'font' is still used in CAD programs. For free-hand lettering there were/are also a wide variety of pen shapes. One form had small plates at the end, so that you were able to write with a defined line-width, but unlike the Barch-Payzant lettering pens, they cannot be run along a straight-edge. In art-class in my first year of secondary school we learned a bit how to work with such pens and ink. The area around Nuremberg specialised in making drawing instruments and materials. The Black Forest area was another area of instrument makers and precision machine tool makers concentrated also there. Many, indeed, seem to have produced not only their own branded products, but unbranded ones for the US American market, where they were labelled by the importers. This ended particularly with the on-set of WW2. This is an interesting piece of trade and manufacturing history ... but we begin to veer away from the subject of painting stripes ...