Graham Boak Posted November 24, 2021 Share Posted November 24, 2021 For another look at this matter see http://www.steelnavy.com/WavePatterns.htm by Donald C Simon 2 Link to comment Share on other sites More sharing options...
foeth Posted November 24, 2021 Author Share Posted November 24, 2021 11 minutes ago, Graham Boak said: For another look at this matter see http://www.steelnavy.com/WavePatterns.htm by Donald C Simon Yes, that is a very good page! He refers to "Principles of Naval Architecture" a few times; the co-author of the latest volume on ship resistance is the author of the code I used to calculate the wave pattern and he occupies an office down my hallway (that is, not now due to Covid...:( ). 3 Link to comment Share on other sites More sharing options...
foeth Posted November 25, 2021 Author Share Posted November 25, 2021 Well sure, why not: https://www.cambridge.org/core/journals/journal-of-fluid-mechanics/article/waveriding-and-wavepassing-by-ducklings-in-formation-swimming/94759A0FF7070D9D7CAC5907594B1781 3 5 Link to comment Share on other sites More sharing options...
Jamie @ Sovereign Hobbies Posted November 25, 2021 Share Posted November 25, 2021 The wake of ducklings D3, D4 and D5 looks like swallows. Who knew? 1 Link to comment Share on other sites More sharing options...
foeth Posted November 25, 2021 Author Share Posted November 25, 2021 Ducks are actually a great subject to study if you're interested in wave patterns (or ducks for that matter) as they clearly show the diverging wave pattern. In fact, for our National Science quiz we actually sent in a question what would happen to the angle of the bow wave if a duck speeds up to fetch a duckling that wandered off.... All my colleagues who did not give the right answer were fired; shame. 3 1 Link to comment Share on other sites More sharing options...
PF Naughton Posted November 26, 2021 Share Posted November 26, 2021 Hi, Also keep in mind though, that things can change a bit in shallow waters, like near a coast. Pat 1 Link to comment Share on other sites More sharing options...
Dancona Posted November 26, 2021 Share Posted November 26, 2021 21 hours ago, foeth said: All my colleagues who did not give the right answer were fired; shame. 😆 That sounds a bit harsh, what the hell did they do to the duck ? 🤣 3 Link to comment Share on other sites More sharing options...
foeth Posted November 26, 2021 Author Share Posted November 26, 2021 We tried keelhauling at first, but our largest models are only about 15 meters long and 2 m wide, so that just didn't cut it 😆 1 Link to comment Share on other sites More sharing options...
ERK Posted December 2, 2021 Share Posted December 2, 2021 Am I right in thinking that hoods anchor chains were White in colour? Erk. Link to comment Share on other sites More sharing options...
foeth Posted January 10, 2022 Author Share Posted January 10, 2022 Woodworking done! Back to HMS Hood! 💕 Build log of this time vampire here: https://ontheslipway.com/lx521-introduction/ 7 Link to comment Share on other sites More sharing options...
ERK Posted January 10, 2022 Share Posted January 10, 2022 Love these - I was very much into hifi when I was younger - Rotel, Q Deck, Denon, Celestion, Something Solid, Monster Cales etc Erk. 1 Link to comment Share on other sites More sharing options...
Adm Lord De Univers Posted January 11, 2022 Share Posted January 11, 2022 Gorgeous work there, although I must admit I am very happy to hear of the continuation of your Hood! Out of interest what wood(s) did you use? David 2 Link to comment Share on other sites More sharing options...
foeth Posted January 11, 2022 Author Share Posted January 11, 2022 I'm happy to continue too The modeling itch became unbearable... the last two speakers were really a drag so I'm glad that is now done. Next weekend I'll make some jigs to support the main deck parts (painting and handling, should have done that earlier) and make a list of supplies I need. My plastic glue bottle evaporated so can't do much at the moment! The wood is American Walnut; I used prefab panels typically used to make furniture. Wenge would have been even more beautiful but the price of these panels has soared over the years.... had to stop somewhere... 1 Link to comment Share on other sites More sharing options...
Adm Lord De Univers Posted January 11, 2022 Share Posted January 11, 2022 Even walnut has gone up in price methinks (I'm currently looking to spend remaining Santa dough on wood bases - if you can recommend anywhere I'd be grateful?). Looks gorgeous though and bet it sounds even better (I'd hazard a bet that walnut would be better acoustically than wenge too). David Link to comment Share on other sites More sharing options...
foeth Posted January 11, 2022 Author Share Posted January 11, 2022 I ordered the panels in two batches; didn't want to commit to three panels before all errors were ironed out. Price went up by over a quarter... Now they don't even have the panels in stock anymore, but the prices for Walnut was about 240 EUR/m2, and I had about 2m in waste alone... (used that for spares and may use most of that for something else). Link to comment Share on other sites More sharing options...
foeth Posted January 26, 2022 Author Share Posted January 26, 2022 (edited) I just bought the Proxxon MF70 Milling Machine (27110), a tiny machine that can be upgraded (or bought) as a CNC machine and offers a much higher rpm than my drill press or lathe: it goes up to 20,000 rpm. I was never able to drill anything below 0.5mm without drills breaking and more or less gave up on that idea without a watchman's lathe or equivalent, until Marijn van Gils showed his brand-new MF70 could drill almost to 0.1mm in brass (See his Victory vs Redoutable build). As the mill is quite affordable and I no longer have to pump all my savings in my recently completed audio project, I bought one as well. So I did use the drill press with a compound table (27100), a precision machine vice (24260) and a nice dividing head (24264). But, the rate of revolutions is low and the entire setup is quite flexible and as such not precise. More important, it does not have a proper collet system but uses a large three-jaw chuck that is inherently terrible for fine work. Imagine my surprise that the MF70 does not have a proper collet system either; it uses the Micromot collet system. That's fine, but these cannot old larger objects such as Proxxon's own edge finders. For my small lathe, Proxxon failed to deliver a proper collet system for the tail stock too, though that was solved by brutally cutting an MC11 ER11 collet chuck . For the mill this is not an option as the spindle doesn't use an MC11 system, but after minor search efforts I found a replacement part at USOVO; a new tuning spindle with an ER-11 chuck and it even comes with a small installation manual. Rejoice! I do wonder why Proxxon seem to be content with their tools not being able to use the entire range of tool mods and expansion sets among them, but at least now I could use the Edge Finder Set (24434) that doesn't fit the original MF70 to align the vice properly and to help finding, well, edges. I did perform some tests with the Micromot collets and these did hold some of my drills perfectly centered, so I can image some people not needing the ER11 collets. I added an extra collet set in a nice box (24154, noticed the Usovo set too late) plus an additional vice (the vice vice). With these options the mill became roughly twice as expensive and I forgot to buy cutters as these are not included---not even one---but small cutters can be bought as small as 0.2mm at other stores. The mill did come with a cross table (27100) and a set of step clamps (24256). Installing the new spindle took about half an hour. I used my sturdy Gorilla-proof 1.5mm Hex wrench the remove the motor plate screws that have been tightened very well and T10 (I think) Torx driver to remove a screw holding the spindle in place. The Usovo spindle comes with two bearings but I kept the bearing of the existing spindle. The set does not come with a tool to (un) clamp the nut or hold the ER11 spindle; I had one for the ER-11 tailstock of my lathe so don't forget to order one if you purchase this new spindle. If you buy the Proxxon collet set or one from Usovo (slightly more expensive but contains 13 over them, the Proxxon only 7), you may also want to order a 3.175mm ER-11 collet separately, the default size of many of my drills. First some experiments starting with something large: a 0.2mm hole through a 0.3mm slice of a 0.7 Albion Alloys tube. Zeroing the drill position is something you'd rather do with the edge finder (that hadn't arrived at the time of writing) and still on the very first attempt the MF70 left my drill press in the dust. The main causes for inaccuracy went into inconsistently clamping the work piece in the vice and parting the small ring using this method. My intended targets were the davits for the 27" whalers. This is a terribly delicate section of the model and it would be really useful if the entire assembly could be mounted by pins into the side of the superstructure when the model is more or less done. These davits are not only very thin (0.5mm rod at the center, filed down to 0.3mm at either end plus a series of 0.7mm rings) but are also angled in slightly inward by 12 degrees. Here drilling in and soldering mounting pins and etched parts to the davit would be very useful; soldering the gripping spar to the davits would be even better as then the whaler could be glued to this spar; rope work can be added last minute. So each 12mm davit needs to be drilled in four times, two pairs of holes at perpendicular angles so the work piece needs to be rotated at least once. With the ER11 chuck still in the mail I started with several different techniques that are all bad. I bent the davit before drilling it, worried that when bending after drilling it may break at a hole as some parts did. The drill was centered by eye (A). Bending first makes it difficult to clamp the davit so I used a block of plastic and a small 12-degree alignment plate (B). Soldering the rings before drilling is easiest, but when traversing in steps of 0.1mm you really need to solder all these rings perfectly if you want to hit them dead center (C). This went well but not really something to recommend as the part will flex. When the part needed to be rotated 90 degrees I tried two plastic blocks and re-centering the drill (D); this is awful as the part may slip (slide or rotate breaking the drill) and your reference is all over the place. Reversing the part---using a bit of rod to eyeball the angle---went better (E); not really good either with the part poorly supported. The prototype did work out nice though (the one that survived that is), after the rings from the first exercise and some etched parts where added (F). With the part flexing and overall experimentation I lost quite a few drills but it was a great introductory exercise. Edit: this post editor on BM is really terrible. Why can't I just type code? 🤮 Edited January 26, 2022 by foeth 12 Link to comment Share on other sites More sharing options...
Jamie @ Sovereign Hobbies Posted January 26, 2022 Share Posted January 26, 2022 That looks like a great tool. I do hope it doesn't make you decide to revisit all the completed work for another rebuild? 1 Link to comment Share on other sites More sharing options...
foeth Posted January 26, 2022 Author Share Posted January 26, 2022 No, I decided to not rebuild anything already fixed to the model... and keep most of the detail that's currently stored in very small boxes. excluding 4" guns and most of the boats Fixing the spar to the main mast by drilling in a small support would be the first thing that comes to main but its fine... really... 1 Link to comment Share on other sites More sharing options...
Adm Lord De Univers Posted January 26, 2022 Share Posted January 26, 2022 11 hours ago, foeth said: Why can't I just type code? That wasn't code? David ps. the davits look amazing. 1 Link to comment Share on other sites More sharing options...
foeth Posted January 30, 2022 Author Share Posted January 30, 2022 (edited) The davits were made from 0.5mm brass rod with both ends tapered to 0.3mm. The pairs of holes were drilled in as explained in this post. Two davits were pairwise bent into the right position and then angled inward by about 12 degrees. Small 0.3mm rings from a 0.7mm tube with 0.2mm holes were soldered to the davits (bottom left); next two small etched parts and the rest of the tubes were added. After a few hours the davits were complete. The gripping spar was next; I sanded the ends a bit to indicate the square region. I didn't file the ends square but flattened the ends in the vice. Two small 0.2mm holes were drilled in where the spar will be supported. I also made two "construction sites" from MDF with four small 0.4mm tubes that will be added to the model as well. The davits and spars fit really well on this temporary position. The spar isn't soldered into place yet, two cushions need to be added that I'll make from magic sculpt pressed gently into a whaler model for a good fit, but these small models need to be made first. Edited January 30, 2022 by foeth 15 Link to comment Share on other sites More sharing options...
Terry1954 Posted January 31, 2022 Share Posted January 31, 2022 Interesting story on the MF17 mill, which is one of a number of model engineering accecories on my wish list. Surprising that you had to adapt it to take the collets you needed to use, but at least you solved that. I'll look into the USOVO products myself. Wonderful miniature work on those davits, and very impressive woodwork on the speakers. Many thanks! Terry 1 Link to comment Share on other sites More sharing options...
foeth Posted February 1, 2022 Author Share Posted February 1, 2022 (edited) I think that for most work the collets that Proxxon supplied might be just fine. I do want to drill in a range of holes over a 7cm span in very thin rod (one day) and then I really really need to align my vice perfectly so I'm running ahead a bit in my planning and the edge finders. Plus, I have been aligning the cross table by trial and error and I want to try the edge finder hoping to improve overall accuracy in general. If you're off by a 0.05-0.1mm it just shows with these small parts at normal viewing distances... Including one of these gripping spars... need to replace one... perhaps... Edited February 1, 2022 by foeth 2 Link to comment Share on other sites More sharing options...
Dave Swindell Posted February 1, 2022 Share Posted February 1, 2022 2 hours ago, foeth said: Including one of these gripping spars. Only one P Evert, Gripes, Griping, Griping Spar 🙂 http://shipwrightjournal.blogspot.com/p/glossary-of-nautical-terms.html That's some fine micro engineering going on there btw. 2 Link to comment Share on other sites More sharing options...
foeth Posted February 1, 2022 Author Share Posted February 1, 2022 Ah, thanks for the correction! 2 Link to comment Share on other sites More sharing options...
Jamie @ Sovereign Hobbies Posted February 1, 2022 Share Posted February 1, 2022 That really is exquisite work. 1 Link to comment Share on other sites More sharing options...
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