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wrkempson

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Everything posted by wrkempson

  1. I had a hard time knowing what I was looking at on the drawing of the beam. This link has a clearer drawing from an engineering book of 1891. https://books.google.com/books?id=LuIOAAAAYAAJ&pg=PA350&dq=walking+beam+steam+engines&hl=en&sa=X&ved=0ahUKEwiO1ZGxxb_PAhWBOT4KHaQAA7YQ6AEIIzAB#v=onepage&q=walking%20beam%20steam%20engines&f=false Scroll down to see your style of beam. This beam is of a truss design and is made in two pieces, the inner skeleton frame which is cast in one piece and the outer strap which is forged in one piece. At either end of the strap are the "journals" for receiving the piston and driving rods. The "journal" for the air pump is cast into the skeleton. The strap is held to the frame by "gudgeons." The illustration in the link above shows the skeleton is thicker in the center. I'm sure this is known to you, but it was a pleasant time for me to track this down, so I thought I would share it with others like me for whom this project is presenting an entirely new field of knowledge. Wayne
  2. I like your observation that the block and tackle would support the arm when pressure was below the relief setting. Could the block and tackle also raise and then secure the valve in an open position so as to blow off steam quickly? Perhaps in an emergency situation or if the boiler was being shut down? Is the outside ball smaller (lighter) than the inside ball? Perhaps this is the manner of making a fine adjustment to the valve, especially if the arm were calibrated on the opposite side. Again, great work on the 3D modeling. Rope can be something of a bear to make until you get the hang of it (no pun). Wayne
  3. I have little knowledge of this subject, but would the boiler also have two or three relief valves? This is inspiring work of a superior quality. Thanks for letting us peer over your digital shoulder. Wayne
  4. I think now is the time to decide on the scantlings for your floor and first futtock timbers. The 62" figure will have two Room & Space measurements for a R&S scantling of 31" or 2' 7". Steel gives the R&S of a 32 gun frigate as 2' 3 3/4 ", but his 32 is shorter than Amphion so a 2' 7" figure might fit for the longer LBP that you have. Into that 31" must fit a floor, a first futtock and a space. Steel gives 13" for the siding of the floor and futtock of a 32, but again I think we might up that to 14". Twice 14" is 28" leaving a space of 3". This is a bit spacey, but I think it might serve. Now, into the 62" will go a two floors, two futtocks and two spaces, but because the spaces are distributed over three gaps (the bends are not sistered) we have 6/3" gaps of 2" air gaps between the timbers. Again, this seems to me to be a bit spacey but not impossible. Now for the 75" figure. This longer distance is due to the presence of a frame that has only a floor timber without a companion first futtock. This is what will cause the floor to "shift" from being on the forward side of the frame pair to the after side. This arrangement was handled in a plethora of ways, but you will have to play around with spacing and disposition to make things work. If any of this makes sense then take it for what it cost you. These are just some speculations I went through when I saw the 62" and 75" figures. Good work all around as far as I can see. Wayne
  5. I think that as a rule I would think of a water line as the inside of the hull planking. Thus, the water, like the inside of the planking, will end at a point that is the distance of the planking thickness from the outer rabbet line; this point will create a line with the rabbet line that is perpendicular to the water line. Think of it as the planking being drawn in, but only the inner side and end line of the planking. This is something I have started doing in the last few years. So, I would construct a circle with the radius of the thickness of the planking (3" in my example) and the center at the intersection of your construction line and the side of the keel. This circle gives the depth of the planking that is let into the keel. Then terminate your water line (or polyline marker) on the circle so that the line is tangent to the circle. Draw a line from this point to the circle center and you will have the 90 degree line representing the end of the planking. Is this why the old drawings have the water lines set into the keel? I think so but can't say I have read this anywhere, it just makes sense to me. The inner rabbet line as drawn on the plans (parallel to the outer rabbet line) is a kind of fictional convention since it does not exist on the ship when built. Wayne
  6. A masterful job. How rewarding to produce such a beautiful set of lines. I think you should be in pretty good shape for the work that follows. Now, may I inject a few remarks on the subject of tracing the plan. On Naiad (I believe it was) Ed did not trace the lines so much as measure from the plan and then place the lines into his CAD drawing. If I do not recall this correctly someone let me know. Anyway, this got me to thinking about the idea of tracing the plan. I could be the one who has brought in the term since in the little treatise that I wrote I must have used a line such as "trace everything" or some such. This is what I did on Euryalus and Foudroyant and the results were quite usable. However, since thinking some more about it, mere tracing is not quite the right way to go. For example, on the inboard profile the decks and inner bulkheads are a specific width (eg, a 3" deck planking). So, rather than tracing both lines, one line is placed on top of the plan line and then the second line is set parallel at the specified width from the first line. And thus throughout the inboard profile plan. In this way we are creating an accurate drawing that has "corrected" the vagaries of the original. Even more significant is the way I would generate the rabbet lines of the stem. Rather than trace them with a Bezier (which I did on Euryalus) today I would generate an arc that is tangent to the top of the keel and passes through two points on the inner rabbet line of the stem. The top of the stem is a straight line which can be drawn in. Then a second arc is generated as tangent to the first arc and tangent to the straight line and passing through one point on the plan. The result is a rather elegant line. In the picture below, the red arc is tangent to the top of the keel, the yellow line is straight, and the blue arc reconciles the arc to the line. When cleaned up the result is the inner rabbet line. When trimmed, this inner rabbet line can be copied offset the prescribed distance (for example, 3" depending on the call out of the hull planking). A similar procedure can be followed to generate the cutwater by a series of reconciled arcs rather than by using a Bezier. In the picture below there are seven arcs that define the cutwater. If you trim off the loose ends the results is indeed serpentine. The hang of the decks I have to put in with a Bezier. I suspect the shape of the line might be a catenary, but even if so I don't think my CAD has a catenary tool anyway. But once the deck line is drawn in, the attending lines indicating round up should be placed in through measurement as was done in the old days. This again results is a more accurate drawing that has reworked the old drawing and thereby corrects what was lost due to age and distortion. I think these observations may apply to the frame/station lines as well, but I have not substituted arcs and lines for the Beziers I used on Euryalus. I am doing just that on my current project. Well, this is a rather long winded way to applaud your work and cast my vote for more of the same. The observations above are just an articulation of my current thinking. Wayne
  7. If I called for using the bottom of the rabbet line for leveling I was mistaken. The top of the keel is correct as you have done. Another way to level the drawing is to draw in the reference line as you have done in red. Then select both the drawing and the reference line. Place the reference point on the end of the red line (use D) and then relocate the X-axis control arm point at the other end of the red line (hold down CNTRL while clicking on the X-axis control point). Then click on the X-axis to rotate the line and the drawing around the reference point at the end of the red line. By holding down SHIFT and then clicking the line and the drawing are automatically leveled. This method eliminates measuring the angle. I was unaware of this procedure when I penned the little treatise you were so kind to mention. I have yet to find a top of keel line on an old plan that was straight. Wayne
  8. Since no one has offered anything, I attach below the waist detail for the frigate Euryalus. It shows modifications made to the waist for 1803 to an earlier plan. The note reads in part: "The Skid Beams, Flats of Qtrdeck, Forecastle & Gingerboards to be shifted into each other &c ..." This does not settle the issue for any other ship, but it is a piece of paper from 1803 that indicates an unbroken run of planking at the waist on a RN ship. I agree that it could be read differently, but this is my take. Wayne
  9. Photographs of the Victorian Victory show two fair leads in the same place outboard. For example, Wayne
  10. I note your water lines are not the same height as those on the original plan and so of course will not match up with the halfbreadth plan. Without drawing them out, I suspect this would account for a great deal of the variance. Wayne
  11. From a quick glance at the original plan, it seems to me the waterlines you have drawn (on the left) are misplaced. It is not apparent why this is, but I think I would draw another set. If the second set comes out like your first lofting, then we are in trouble. I suspect a second effort might come closer to the original, however. Again, a quick glance says to me that something has been missed along the way. Diagonals can be thought of as a cross between buttock and water lines. Draw a diagonal line on the body plan. This is normally drawn through the turn of the bilge. The angle is somewhat arbitrary. Anyway, draw a diagonal line on the body plan where it will be a straight line. Then project this line to the half breadth plan with the same procedure as projecting a water line. This gives you the look of the diagonal as if looking at it from above. It will be a curved line, but will not match the waterlines because it isn't one. Then project the diagonal line from the body plan to the sheer plan using the same procedure as you do for a buttock line. This will result in a curved line that does not match the buttock lines because, well, it isn't one. Then check for fairness on these two curved lines. If you have done your station lines correctly the curved diagonal lines will be fair. Employing multiple diagonal lines offers multiple checks on the fairness of the hull. This is one reason for lofting or laying off the lines on the floor. Wayne PS on further reflection, your lines seem to treat the stern post as if it were perfectly vertical rather than angled. Is this so? PPS an image of your body plan (station lines with the waterlines) might help analyze what is going on.
  12. Currently I am using TC v19 Pro. I have previously used the v14 Deluxe and Pro. I started with v4 (DOS based) before really getting into TC with v8. As per daves, the Deluxe versions are more than adequate for drawing plans. The Pro versions add the possibility for 3D modeling to a greater accuracy than Deluxe. (That is, Pro has a lofting function, Deluxe does not.) Earlier versions of TC are available at substantial savings and are well worth investigating. I have not gone to v21 or TC2015 because of the cost and the lack of a perceived need to upgrade. Wayne
  13. The problem with drop planks is that they hurt when they hit your toe. The problem with stealers is that they need a quarterback.
  14. I believe this is a photo of the model stove at RMG. By looking carefully at the top one can see the relationship of the turbine to the pipe. With proper gearing it should not be hard for the mechanism to accomplish its purpose. (I don't remember where I found this many years ago.) Wayne
  15. Ed, please take the photos. I find shop clutter in the background to be both charming and instructive. By the way, the photo of joggling the planks I thought was an entire tutorial on the subject. Truly well done, as is all your work. Wayne
  16. Wiley, I'm not sure I understand your question about objects. One can do some pretty impressive modelling in 3D with TC. Creating a hull form such as we deal with in the eighteenth century is something of the Holy Grail of TC modelling. One can get pretty close, but one almost always runs into a quirk or two for various reasons. At any rate, the 3D hull is built off 2D lines anyway. After drawing up plans for Euryalus in 2D I did put together some 3D modelling. For the purposes of making patterns for cutting out timbers 2D was sufficient. That said, I did use 3D to test fit parts. Also, I found that using 3D was an easier way to project the stern timbers, and maybe the head timbers, but that's about it. Some of the fun of drawing (actually, redrawing) plans is connecting with the methods used by the old guys in the loft. Just for laughs, attached are some 3D renderings. Other programs are better than TC for making and texturing 3D ships. Wayne
  17. Frank, The biggest thing has to do with loading in the photo of the paper plan. Today, I would try to load in the plan as one image, or at least as one image for each of the profile, body and half breadth plans. Using Beziers to trace the curves on the plan works well. Today I might use arcs and reconciling arcs simply because that is closer to how it was done "back then." If you use Beziers things will work out fine so this is more in line of a technical matter. In fact, when i say there are things I would do differently they are mostly technical issues on this order. I don't think you need to be overly concerned, just use what makes sense to you and proceed full speed ahead. Wayne
  18. TurboCAD will do everything you need for lofting plans and generating patterns. Frankly, only the most basic commands are mandatory given that the old guys used only straight edges, compasses and flexible battens (it's a little more ornate than that, but the point remains the same). Read up on SNAPS and get a good handle on how they operate. The HELP feature has all the information you need. Grant was kind enough to mention my little treatise. I wrote it many years ago as I was learning the process myself. There are many things I would change today, but it has the general drift. Today I don't think I would rely on Beziers but would use arcs. Also, the section on entering the plan into the computer is very much outmoded and is way more complex than necessary. All CAD programs seem daunting at first, even to folks who have used a different CAD program. Just plunge in, educate yourself slowly on the basics, consult the HELP feature often, and don't be embarrassed to ask a question every now and then. Also, there are some instructional videos on YouTube. I find them laborious at times, but they do answer a lot of questions. Inquiries specific to lofting can be asked here. All the best to you. Wayne
  19. Once your plan has been photographed and saved to your computer, use Insert>Picture>From File and select the photo for insertion. Then click on the workspace to define where you want the first corner of the plan, then click on the position for the opposite corner. Also, remember to consult the Help feature. There is a lot of good information there. Wayne
  20. It just happens as far as I know. Thank you for the compliment. Wayne
  21. I don't have TC Mac and could not reproduce your problem in TC19 for PC. However, the TC forum seems to have a little bit on line widths not printing properly. If I understand the chatter over there, it may have to do with your computer, the printer, default property settings, TC versions, and the tooth fairy. You might try http://tcmacforum.imsisupport.com/ and ask your question there. My experience has been good with the TC community. If all else fails, I have called the company support folks and gotten pretty good response. I know this isn't direct help, but it is what I think I would do next if no one else can come up with an answer on this forum. Wayne
  22. Well, there's a couple of hours I won't get back; but worth it. It took me a while to realize the two eastern quadrants of the outside curve comprise a semi circle and that for the outside curve the spiral begins at the bottom. The inner spiral begins at the top. How to locate the center of the semi circle took a minute as did the proper way to construct and locate the inner square. I began by looking up how to draw the volute of an Ionic capital (which led me down some false paths) but did get a start on how to back engineer your drawing. Thanks for the challenge. I have no experience with architectural drawings like this, so it was a couple of hours of pure learning. Not bad. My end product looked (to my eye) the same as yours, so no sense posting it. Nonetheless, I guess I qualify as one of the more obsessive among us! Wayne
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