wefalck

Trying to keep up standards **************************************** Some time ago I purchased a 12V motor from a Chinese source that is supposed to run at a nominal speed of 3000 rpm. Considering is length of 71 mm and a diameter of 51 mm with an 8 mm drive shaft I expect it to have sufficient torque for the purpose. The data given by the seller were rather cryptic. The mounting of the motor caused me some head-scratching. The original intention was to use a bracket similar to the one used on the lathe toolpost-grinder shown below as the mock-up. Self-contained drive unit as used on the toolpost-grinder This would have resulted in a self-contained drive unit. However, the motor would have fouled the cross-slide, when the y-slide is fully run out. Making the bracket longer would have solved this problem, but I was afraid of the vibrations this long lever might transmit and the distortions to the y-slide. Another possibility would have been to mount it upside-down over top of the y-slide, but this would have raised the centre of gravity of the whole machine considerably and transmitted vibrations to the system. In the end I make, for the time being, a simple bracket that uses the two screws with which the extension of the y-slide is screwed down. Motor mount The lathe and grinding spindles were meant to run at maximum speeds of around 4000 to 5000 rpm. Therefore, a slight stepping-up compared to the motor speed would be permissible. As the motor bracket does not provide for any adjustment of the belt-tension, I copied the pulley on the grinding spindle for use as a motor pulley as exactly as possible. It will be put upside-down onto the motor, so that the belt can be shifted for stepping up (1 : 1.4) or stepping down (1 : 0.7) speeds without the need for adjusting the tension. Most of the speed control will come from the electronics in the power-supply. The pulley on the grinding spindle has a 75° V-groove for 3 mm round belts. A V-groove can be cut by either setting over the top-slide, or using a pointed tool with the appropriate angle. I had to grind a HSS-toolbit with this angle, checking it against a template. The two grooves were cut using a stepping method. Cutting it full depth would not be possible. I order to ensure concentricity between the pulley-bore and the groove, first the step in which the set-screw is located was turned and then the piece turned around for drilling/reaming the bore and cutting the grooves in the same set-up. For cutting the grooves the pulley was supported with a revolving tailstock centre. Steps in machining the motor pulley The finished moto pulley The two drive pulleys To be continued ...

Breaking 2 mm drills ? Sounds like brute force ... OK, done this as well, but it was in steel ... Personally, I prefer collets. Don't know the Dremel products, but the Proxxon ones are pretty good concerning run-out. The tightening nut is smaller than the chuck and, therefore, you can see better what you are doing.

I found this question - which seems to pop up from time to time, a rather odd. Divide the real size of the hole you want/need to make by the scale - in your case 48, and you will get the diameter you need. Normal CV or HSS bits come in 0.1 mm graduation, but can be also obtained from watchmaking suppliers and other speciality suppliers at 0.05 mm intervals. In practice the 0.1 mm step should be sufficient. Sizes below 0.3 mm are not so easily obtained and are rather fragile. Watchmakers suppliers also have drills with straight flutes that are much more rigid, but rather expensive. Another option are surplus carbide drills that are available on the Internet at reasonable prices down to 0.1 mm diameter. Beware these are even more fragile than HSS drills and may not be suitable for hand-held drills.

Thanks again, gentlemen *********************************** As for the other dial fabricated earlier, a pressure pad provides for an adjustable friction stop. The outside rim was also given a treatment with the concave knurling tool described earlier. Knurling the rim of the dial The engravings on all dials were filled-in with black paint and when the paint was dry, the dials were slightly rubbed-over with fine wet-and-dry paper to leave crisp black engravings on a satin surface. The finished dial at its place Finally, the cleaned cross-slide was re-assembled with the new dial. Re-assembled cross-slide To be continued ....

It was a joke ...

'Red Oxide' paint should be the right track. Lead-based pigments have been around for centuries, but were much more expensive then the iron-based pigments. You have to turn the lead first into the oxide, while the iron-oxide only need to be refined. I would think that there was a certain variability in the hue due to the variability of the natural pigment. Howeever, it should be probably more brownish than orangey. Cadmium-red (which does not contain Cd anymore today) would be too bright. I would assume that the paint was based on lineseed-oil, rather than on animal oils. Lineseed-oil, the classical verhicle for 'oil paints' is a drying, i.e. oxidising, oil.

Excellent crimping tool for the metal rim around the shields !

Slightly off-topic, but there various uses for ladies' stockings. For instance, the purse-net on this 1:90 scale botter model was made from a (new!) ladies stocking: I also know that some people make shells for small boats from stocking-reinforced resin over a positive form.

Liberto, I know, how it is done in 1:1 scale (thanks for the interesting video, btw - but keep in mind that the Vikings didn't have bandsaws and electric hoists ), but wondered how you did it on the model. Are the nails really clenched/roved, or did you 'cheat', i.e. just cut them above the copper disc ?

Ochres are ferric (i.e. trivalent) iron oxyhydroxides of varying composition (generic formula FeOOH). The less water you have, the more reddish they tend to be. They are the residues from a particular weathering environment. In some parts of the world there are quite pure occurences, for instance in southern France (see e.g. https://en.wikipedia.org/wiki/Roussillon,_Vaucluse), so that it can be mined for pigment. Otherwise, red soils are quite common in the tropics, but contain a lot of sand and other impurities. From Wikimedia

Looking again on the images, I think in the area around the stem one sees copper sheathing. What is a bit strange is the somewhat fuzzy waterline that looks painted on. Perhaps she had a reddish boot-topping ?

Red ochre is one possible pigment in a paint and would have been a lot cheaper than most other red(dish) pigments,

Excellent ! Are you clenching the nails over the copper discs ? Not sure what the original technique was, but as the rest seem to be pretty much according to prototype, I assume that this is what you do.

Saludos, unfortunately, my written Spanish is rather meagre, but I can read it reasonably well Interesting project and good workmanship ! I also like the miniature desk-top belt-sander you fashioned from the Proxxon hand-held belt-sander. I have been thinking of a similar project.

I gather the fibre glass matts are there to take up the strain from the wood in changing humidity and prevent the surface from cracking. Resin alone would not be able to take up these strains. Still I was wondering, whether some good marine varnish wouldn't be sufficient because the planking is on some composite board that should take up the strain.

Sorry, druxey, saw it and then forgot it. It came to my mind, because the wooden German research vessel GAUSS (1901) was kitted out in a similar fashion.

Textile paints - as far as I know - are not meant to close-up the meshes in the fabric. However, this is really what you need to do, because threads and meshes even of the silk are too coarse. At the model scale you just want to have a hint of texture. In fact the silk only acts as a pliable and non-directional backing. The thicker the layers of paint, the more difficult the furling is going to be and the less 'natural' and to scale it will look. That is why I suggested to first apply a minimum of paint and then, after furling, apply more paint, if needed. However, this requires a bit of experimenting. In fact, I believe Viking-age sails were woven from wool, rather than flax or linen, which is not easily available in the North (but may have become available through trade routes from Rus or the Baltic areas). This may be good news for model representation, as you would have a rather coarse fabric. When painting the sail you can give it also more plasticity by applying shadows and highlights - just as figure-modellers do to depict fabric. You may want to consult related Web-sites or fora.

Do you mean a 'furling' sail, or a 'furled' sail, i.e. is it a static model, or do you want to move the sails ? If you use the silk mentioned as a basis and give it a thin coat with diluted acrylic paint to close the 'holes' in the fabric, it stays reasonably flexible and can be furled before(!) being really painted. A too thick coat of paint may come off. However, this may require some experimenting. I would also paint the two different colours as base-coat before furling in order to see, where the separation line between the colours will be. Constructing the sail from individual panels could be difficult then, as the 'seams' would not be very strong and my come loose when furling. However, I have done this (individual panels) also on the model in 1:60 scale below and they furled reasonably well. I had some problems with the bolt-ropes though.

I always had a weak spot for those mahagony run-abouts since I was a small boy and went down to the boat-yard at Lake Constance (Germany), where my grandfather kept his wooden dinghy with a small outboard engine - and where a couple of them were moored under a wooden roof for protection. I loved the sound of the heavy engine, when they were taken out occasionally by their (rich) owners. Missed this building log until today. Nice job !

According to an old textbook on marine engineering (Steinhaus, 1870), antifouling paints were available at that time in a variety of colours, including reddish brown, green, black, white, yellow, and blue. Basically, you just add the pigment of your choice. Their biocide effect was based on inorganic lead and in particular copper compounds. Concerns over heavy-metal contamination in harbour muds and the search for a higher efficacy led to the development of tin-organic compounds. However, these are being phased out since the 1990s, when it was discovered that they act as 'endocrine disrupters', meaning that they lead to malformation in aquatic animals that come into contact with them. The problem is that antifouling paints not only act toxic to things that want to stick to a ship's bottom, but slowly wear off (which is part of the antifouling process) and become dissolved or settle in particles in marine sediments. Here their toxic or endocrine disruptive actions continue. I believe in more recent years antifouling paints put more emphasis on non-stick properties and slow wasting that detaches whatever tries to held a foothold. I gather red(dish brown), green, and black were generally preferred colours, because these resemble the appearance of either coppered or tarred ships bottoms. Muntz-metal bottoms would have looked yellowish to green-greyish, depending on their age. The Austrian navy actually used a pinkish paint on their iron and steel hulls before WW1, btw. Appart from being a waste of money, paint may not stick very well to copper because of the oxide layer that forms rather quickly on its surface. The picture in the first post is not very clear and I don't know anything about the vessel in question, but would it be possible that a protective sheathing of wood was applied on top of the coppering for travelling in areas where there was floating ice ? This sheathing in turn may have been painted.

You know, many of us may have had similar thoughts, but never comitted them to the WWW ...

I used UHU hart in my youth, but then got away from it, thinking that it is a close relative to their original UHU Alleskleber (general purpose cement), which was frowned upon as being not a serious technical glue. However, UHU hart is based on cellulose nitrate with some ester as a solvent. Cellulose nitrate actually is one of oldest plastics and not based on mineral. Originally invented to replace ivory in billard balls its main use became film materials. Dolls, table-tennis balls and a variety of other consumer products were made from it. It was phased out as film material in the 1950s already, as it burns easily. A technical summary of UHU hart can be found here: http://www.uhu-profi.de/uploads/tx_ihtdatasheets/RS674_Technisches_Merkblatt_tds_hart.pdf It is in German, I couldn't find an English version. In the meantime, I found out that UHU Alleskleber consists of poly vinyl acetate with some ester als solvent. It stays more less rubbery for decades, as oposed to UHU Hart, which becomes hard and somewhat brittle. For some decades now I have been using UHU Alleskleber to glue the metal edges onto my glass-cases. It seems to be less messy than clear silicone. One problem with glue/cement in tubes is that due to the vapour pressure of the solvent it has the tendency to squirt or run out of the tube, even if you don't squeeze it. I always store my tubes with the tip upright, which largely eliminates the problem and loss of glue.

Making a clove hitch seems to be as easy, as an overhand knot. So why not using it ? If the ratline-material is thin enough, i.e. to scale, the knot will be at scale as well. The available yarns will be the limiting factor, not the knotting.

It is a question of scale and what the base material is going to be. Real fabric is not really suitable except for the largest scales, say 1:20 or above, due to too coarse weaving and thick threads. Personally, I would go for either the silk fabric that is/was used in model aeroplanes or fine paper. Both can be stabilised and shaped using diluted white glue or thin lacquer. They then can be painted e.g. with acrylic paints. Below is an example from my own production (in 1:90 scale): The sails are put together from individual panels. I gather something similar could be done for your sail and the panels painted in different shades of red (ochre). What is the latest research on Viking-age sails ? I am not up-to-date there, but believe that at some stage diagonal panesl were discussed and re-inforcements with leather stripes.

I believe all ships sailing in Chinese waters up to the end of the 19th centurey had to be armed at least for insurance purposes. However, it seems that many captains/crews preferred not to put up a fight with the pirates, if they could not out-sail them, because then, in case of capture, the Chinese pirates would then just kill them. If they didn't put up resistance, there was at least some chance that the pirates would let them go. I recently read an account of a German vessel of around 1860 that got captured: the crew was put into one of the ship's boats and set adrift; when they landed on an island in the Chinese sea, the friendly natives stripped them of their clothing, this being the only thing they still had; eventually they were rescued. This lead to a German navy presence in the Chinese waters. The pirate problem has never been resolved completely in these waters and as we all know, it is now a serious threat to shipping in some parts of the Indian ocean, resulting in commercial ships being armed again.