KeithAug
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And so back to the frames:- I did, however, start with a diversion. I decided to print out the side elevation. I tried printing at 1:36 scale but this proved a step too far as the loss of definition was marked. At 1:72 scale the definition was reasonable and multiplying dimensions by 2 to get the final scale seemed a reasonable compromise. At 1:72 the image printed out on 6 A4 sheets. I made a jigsaw of these and mounted them on a piece of MDF. I then spent a long time accurately cutting out templates for all 46 frames. You may recall that I had coloured the edges orange as a cutting guide. I offered the cut out templates up to the plywood that the frames were going to be cut from and decided that the orange wasn't a good contrast for sawing. To provide contrast I went over the edges again with a blue felt tip marker. A this stage I also marked on; 1) the deck - red line on the above picture and 2) the cabin floor blue line on the above picture. The curvature of the deck isn't very great so I printed out a set of large radius curves from the web and used one of these to make a marking out template from a piece of scrap 1/64" ply. I used the 20" curve as this seems to give the desired curvature. I had purchased 4 sheets of 48" x 12"x 3/16" ply from which to cut out the frames. I have used the supplier before and they duly arrived a couple of days later - unfortunately they sent 1/8". I sent an email which was responded to within an hour saying they had already dispatched replacements and that I could keep the 1/8" sheets. The replacements duly arrived the next day. Good service is not dead! I took some trouble in mounting the templates on the ply. Pencil lines were drawn at right angles to the edges and the templates were aligned accurately on both the mounting board edge of the template and on the centre line. Hopefully this will help with frame alignment during the build. I used a glue stick (Pritt Stick) for mounting as I wanted later removal to be reasonably clean and easy. I tried to minimise waste. Some time later I had all 46 templates mounted (and moved on to the snooker table as I had been "encouraged" to vacate the dining room). The next step will be some serious scroll sawing - a new learning experience as my previous use has been very limited.
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Doris I have found your build much too late. It is amazing what you achieve. I'm very impressed.
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Thank you Michael. I thought you might say I should have put bolts in the 4 holes in the cone. I actually tried as I had a few 1mm thread x 1.5mm head spectacle screws. Having spent some time cutting one down to size only to loose it, then doing it again and inserting it, I decided I couldn't see it at the bottom of the hole anyway.
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Thank you John. Valeriy. You caught me out taking a short cut. For a 30 degree tip angle the calculated mid chord angle is 40 deg and the hub angle is about 60 degrees, (I used to design compressor blades which were equally affected by changes in velocity with diameter). I could have made a former and done a bit of tin bashing but I decided not to. Perhaps next time.
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So to finish the prop. The next step was to make the hub. I started with a .500" diameter aluminium rod. I drilled the bore on the lathe (.125") to take the prop shaft. I then mounted the rod in a square collet block and drilled cross holes (.200") to take the blade bosses. The rod was then moved back to the lathe and the end was turned down (.400" diameter) prior to turning the spherical hub. My ball turning tool then got one of its rare outings to turn the ball of the hub. The ball is actually symmetrical about the 4 radial holes - the camera seems to have introduced an optical illusion to move them off centre. The ball was then parted off to the correct length (as per drawing). I next made the exit cone from brass rod - .375" machined down to .282". The rod was then mounted vertically in the mill and the 4 mounting holes were drilled axially to form the bolt holes. Then back to the lathe to machine the 45 degree cone angle before parting off. I did leave a .125" protrusion on the parted off face to locate in the axial hole in the hub. The exit cone was then pressed into the hub. The blue pencil gives some idea of scale. The prop shaft was then superglued into the hub and then the blades were glued into the hub using 5 minute setting epoxy to give me time to set the angles. The gluing of the blades was done with the hub held in the lathe chuck and I used a piece of ply (cut at 30 degrees) to set the angles. I then made the prop tube / boss and did a bit of s clean up and polish. So now (unfortunately) its back to those annoying frame templates.
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Tom Hi Tom. They are fine with the exception that my fingerprint recognition on my phone does not recognise me. I think I am now safe to commence my bank robbery career. Re rigging must have been an awful pain on short tacks.
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So it's about time I made something to relieve the draughting blues. I am developing a habit of having go at the prop early in the build so here we go again. I don't have any photos of Germania's prop but I can get enough detail from the plans (shown earlier) to get an idea of the size and shape. From these drawings I think it is a 4 bladed variable pitch prop. I did a web search of variable pitch props and picked up a couple of images that were similar in shape (albeit they had 3 and not 4 blades). With the available information I drew and dimensioned the prop. I started the construction with a piece of brass machined to .385" width by .375 deep. This was to be the basis of the 4 blades. I machined one end to give a .040" web that would form the basis of a location / mounting pin. This web was off centre as per my design sketch. On to this I stuck the blade shape. I then shaped the blades with jewellers saw and files, leaving a small attachment web. Then it was on to the mill to slit off 5 blades - one spare in case of mishaps or workshop disappearances. I then cut off the web with the jewellers saw and feathered the blade edges with a needle file and emery cloth and then gave the blades a quick polish. At the base of each blade is a conical sectioned hub. I turned up a brass rod to .200" diameter with a .040" axial bore. I then cut a 45 degree chamfer on one end. This was then moved to the mill and the chamfered end was slotted with a .040" slot through the centre. I could have used a slitting saw to form the slot but thin slitting saws tend to wander off the desired line, so I made a single point slotting tool. This consists of a round bar which fits in the mill chuck and holds a tool made from high speed tool steel. The mounting pin on the blade was then inserted into central hole in the hub and the blade was soldered in place. Then it was off back to the lathe where the blade hub was parted off .100" long. More to come later.
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John - yes I am keen to move on - I may however have a go at the prop first - as a reward for getting through the drawing and colouring in marathon. Wefalck - Thank you for the link - I have done a lot of internet trawling but I hadn't come across this particular build. The photos will be very helpful and any plan information would be most welcome if you could enquire on my behalf. Thank you for your help. Mark - I spent a long time wondering about this when I was building Altair. Here is by best shot at the answer: The worst case is the obstruction caused by the (fixed) stays that brace the fore and main masts. Clearly the topsails have to be rigged on one tack and they are unobstructed by the rigging on the tack they are hoisted on. When going about, one option is to take them down and re rig them. I think only the most dedicated of crews would do this - and then not often. Most crews seem to ignore the problem and just accept the loss of efficiency by letting the sails lie on the rigging lines. I have only ever sailed sloops so I'm not an expert and would welcome any other views.
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I completed the final sections. I plotted them on a separate sheet to avoid the conflict confusion. As previously i have attached the PDF. Schooner 2.pdf The next step was to make the templates for cutting out the frames. Fortunately in these days of scanners and printers things are much easier. The scanner decided to scan the image at 94% so when I went to the print programme I adjusted this back 100% and checked the scale lines to confirm the accuracy of the print, all was well. I also needed the mirror image print as a half hull model wasn't my plan. After a bit of searching I fount the flip horizontally button and hey presto I had the other half. Then followed a large print run 46 of each - port and starboard. it took a while not least because of the hunt fort the replacement black cartridge. The halves were joined with a glue stick and then each frame was coloured up to identify it for cutting out. I did a lot of colouring in - just like being at school. Some time ago I had found some small scale plans on the internet. As plans go they lack a bit of detail however with the aid of many photographs I think they will be adequate. I need to do a bit of scaling up and printing to get the plans to a workable scale. My initial test on scaling up showed that the definition was reasonable.
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Paul - I hadn't thought about it and you are probably right that it would help. I am getting a bit fed up with draughting so I may short cut and go to cutting out the frames and then check what it looks like "in the flesh". I'll probably regret it and have to revert to your suggestion - oh hum!
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Having completed the forward sections I moved to the aft end. The lower aft end of the keel is perhaps the most poorly defined area not only because of the loss of line definition in scaling up the original but also because of closeness of the lines on the plan view. This post covers the definition of frame lines negative 7 through to 11 (nineteen in total). Producing the frame lines required a degree of interpolation to get something that looked sensible within the frame and between adjacent frames. I enclose the PDF of the result for anyone interested. Frames4.pdf I found that drawing the keel bulb on frames forward of those being defined was helpful in getting my mind around the keel shape. The bulb lines in question are marked 15, 14 & 13 on the drawing. They can be ignored when I get on to cutting out frames as they will be covered on the fully defined frames later. Again I have defined the datum line, the building board alignment slot, the water line, deck edge line and rail line. Additionally I have noted the levels of the cabin floor as it rises in steps towards the bow. To complete the lines I now need now to define the frames 11, 12, 13 & 14.
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Michael - My time in the Rolls Royce Draughting Training School was a long time ago (1969 / 70). I am very much worse than I was then. The last time I drove a drawing board was in the RB211 Design office in 1977. Which leads me into a story. I had been asked to work overtime one night and was sitting alone at my stool in front of a long line of vacant 6x4 feet drawing boards. I was engrossed in designing a new style of combined engine oil feed and scavenge pump and quite oblivious to the rhythmic clanking of the bucket and mop as the cleaning lady worked her way steadily down the office. Suddenly as she came level with my station she stopped and spoke the following words that, in their irony, have lived with me to this day:- She said "Sorry to bother you but don't you get board just drawing stuff all day". I looked at her mop and bucket in amazement incapable of making sensible reply. Unfortunately I moved into management before the advent of CAD and never bothered to learn.
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Dan I am only as far as November 6th but by the rate you are progressing I need to get a move on lest you finish it before I catch up. A fascinating build. I found it interesting / surprising how much photographic evidence you found given the era she inhabited. A great project which I look forward to following.
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Hi Dan One of the high priorities on my catch up list was to see how Michelangelo turned out. I have to say she is beautiful and only bettered by you detailed log of the build, very well done. I'm now heading off to have a look at Leviathan.
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Patrick. I just enjoyed catching up. She is a weird vessel, however as usual, your ability to work the detail at this scale is most impressive.
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ancre La Salamandre by tadheus - 1:24
KeithAug replied to tadheus's topic in - Build logs for subjects built 1751 - 1800
Happy new year Pawel. Hope you are keeping well. Lovely gun. -
Mark - Looking good-----steady as she goes. Try splicing the mainbrace - I always find it makes things look even better.
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Just a bit more draughting progress. I finished the forward section frames - 15 through 38. I was pleased with the result although these are the most easily defined frames because the are reasonably well spaced and don't conflict with one another. I also marked the waterline, deck edge lines and the rail lines on the sections. Additionally I have included the upstand and datum line that will be used later for mounting the frames (inverted) on the building board. The slot in the up-stand will form a cut out to align the frame centre line on the building board - this will come clearer later. I have included below the PDF file of these frames for downloading. I have also put x and y scales on the PDF to allow scaling when printing. I found that in my case the scanned PDF came out at 93% full size and I had to adjust the size in the print programme back to 100%. I checked the printed scales measured 6 inch as original drawn as a check on the reproduction accuracy. Schooner 1.pdf
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I started plotting the frame section lines. The drawing numbers the frames with frame 0 at the steering position. Frames 1 to 38 are forward of the steering position and frames -1 to -7 aft of it. It's a bit slow going but I am making progress. I have commandeered the dining room table - somewhat warmer than the workshop at present and my wife can find me more easily. The Christmas table cloth hasn't been removed yet. My draughting arrangements are somewhat basic, MDF for drawing board, my woodworkers square, dividers, french curves and a much overused eraser. Oh! and a laptop to give the impression of sophistication. Never the less it seems to work and the bow sections are coming out well. I will publish PDF's of the sections in a later post. .
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Richard I emailed the builder but didn't get a reply - probably a victim of their spam filters. I not too worried as I think I will get a decent result from the image I have. The instruments are Staedtler. The large compass has a nifty collet arrangement on the adjustment screw to give fast action as well as fine adjustment.
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I have made a start on defining the frames I started with the small web image. This was originally in a magazine and probably scaled about 6 inches long. I had a play with it in the Mac iPhoto package basically whitening and sharpening the image. The plan and side elevations improved more than the image showing the frames. This wasn't a big deal as the frames were only for the fore part of the yacht and anyway I thought plotting the frames from the plan / elevation was likely to be more interesting. I printed the plan / side elevations at 1:36 and 1:72 scale. 1:36 is the upper 2 sheets in the next photo, the lower 6 sheets are 1:72. Scaling up to 1:36 produced rather wide / poorly defined lines. 1:72 was somewhat better. As I was going to draw the frames at 1:36 the scale of 1:72 worked well as I could measure across the matching plan section lines and use this dimension as the centre line to hull dimension on the 1:36 frame sections. I felt the urge to check that the plans were reasonably accurate as I was worried that length / beam scales could have been distorted. Hence the following check calculations:- The error line (red) shows the maximum error to be about a third of a percent which I am happy with. It is probably worth stating that the frame section lines are spaced at 1 meter (full size) or circa 1.1 Inch at 1:36. For building I had to consider how many frames to create. 1.1 inch spacing gives 46 frames and of course 2.2 inch gives 23. I decided to go with the larger number.
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