pheonix Posted November 11, 2019 Share Posted November 11, 2019 Very nice looking engine. P 1 Link to comment Share on other sites More sharing options...
DMC Posted November 11, 2019 Share Posted November 11, 2019 Nice! You are certainly making good use of “The Book”. Dennis 1 Link to comment Share on other sites More sharing options...
Torbjorn Posted November 13, 2019 Author Share Posted November 13, 2019 (edited) On 11/11/2019 at 5:56 PM, DMC said: Nice! You are certainly making good use of “The Book”. Dennis Yes - reading it was what made me want to build something in the first place Discovered I had made a booboo with the tailplane struts. I had for some inexplicable reason put them supporting the leading edge. This doesn’t make much sense so I moved them to where I think the spar is. Before and after Edited November 13, 2019 by Torbjorn 6 Link to comment Share on other sites More sharing options...
Torbjorn Posted November 13, 2019 Author Share Posted November 13, 2019 Hmm, looking at the image a square cross-section does not look smart. Wonder what I was thinking when I did that... Link to comment Share on other sites More sharing options...
Hewy Posted November 13, 2019 Share Posted November 13, 2019 Real cracking job torbjorn,👍, the engine also looks great so far 1 Link to comment Share on other sites More sharing options...
Torbjorn Posted November 20, 2019 Author Share Posted November 20, 2019 Finished the engine and made the struts holding it. N-shaped, with bars in between. Took some care to get them aligned since any deviance will be incredibly obvious. Made them out of hardened 0.3 mm brass rod, to ensure they are properly straight. I’m also replacing the tail struts... couldn’t stand them being square in cross section. Now I *really* can’t put off making the upper wing any longer. 10 Link to comment Share on other sites More sharing options...
pheonix Posted November 20, 2019 Share Posted November 20, 2019 That engine is very realistic - as good as many kit samples that I have seen. Getting the platform for the engine is important - as you write it really must be square or it stands out horribly. The upper wing shoukd not present too difficult a problem, and with a simple jig you should be able to align it properly too. P 2 Link to comment Share on other sites More sharing options...
Courageous Posted November 20, 2019 Share Posted November 20, 2019 Looking really smart. Stuart 1 Link to comment Share on other sites More sharing options...
DMC Posted November 21, 2019 Share Posted November 21, 2019 Top scratch building skills. Dennis 1 Link to comment Share on other sites More sharing options...
jrlx Posted November 23, 2019 Share Posted November 23, 2019 Superb work on the engine and struts! Very well done Cheers Jaime 1 Link to comment Share on other sites More sharing options...
Torbjorn Posted November 25, 2019 Author Share Posted November 25, 2019 (edited) Thanks for the likes guys On 11/20/2019 at 11:51 PM, pheonix said: That engine is very realistic - as good as many kit samples that I have seen. Getting the platform for the engine is important - as you write it really must be square or it stands out horribly. The upper wing shoukd not present too difficult a problem, and with a simple jig you should be able to align it properly too. P I’ve started, but not without difficulty. The plan was to use a 1 mm plastic sheet as base and skin it with 5 thou sheet with ribs embossed. The base is cut and sanded as a single piece, but due to the raked wings, a separate covering (I find the designation “skin” a bit morbid) is needed for each of the port and starboard sides. The raked wing poses a problem for creating an aerofoil shape: it can’t be easily curved by simple bending. Making two halves was an option, but I wanted the extra structural stability. A first test ended in failure. I naively clamped the port half over a strip of wood like so (and clamped at the trailing edge, which is not shown): and shoved it into the oven, trying to bend one side at the time. The centre line is sawed a bit through from each side to allow a change in curvature there. I had the oven too hot; out came a distorted starboard wing looking like a buckled aluminium wing and the port side showed imprints after the clamps. Lesson learned, I made a more solid clamping jig, setting the curve at both sides at the same time making sure that no sharp edge is in contact with the wing. Then started the oven at a low temperature (50 centigrades - the lady was rising some bread dough at that temperature, she sounded rather surprised finding my contraption next to it a bit later) and gradually increased until I achieved plastic deformation (i.e. the wing keeps the clamped shape after removing clamps). The trick is to reach a temperature giving this deformation without causing warping due to bad clamping or too much heat: in my oven that happens at 90 centigrades (note to self). The wing base is here somewhere: Result: The leading edge looks a bit flattened on the photo, but that is only an optical effect caused by the rounded tip. Edited November 25, 2019 by Torbjorn 9 Link to comment Share on other sites More sharing options...
pheonix Posted November 25, 2019 Share Posted November 25, 2019 Very neat way of bending the plastic for the wing without having to cut it in the centre. I had a similar problem with the H-B W13 but there was a straight centre piece to which I could attach the outer panels. It would not have been possible to make that wing in one piece but future flying boat wings with sweepback may be different so I will bookmark this. P 1 Link to comment Share on other sites More sharing options...
Torbjorn Posted November 30, 2019 Author Share Posted November 30, 2019 (edited) On 11/25/2019 at 6:08 PM, pheonix said: Very neat way of bending the plastic for the wing without having to cut it in the centre. I had a similar problem with the H-B W13 but there was a straight centre piece to which I could attach the outer panels. It would not have been possible to make that wing in one piece but future flying boat wings with sweepback may be different so I will bookmark this. P The base turned out better than I hoped for, but it was difficult to make the 5 thou skin conform to the underside curve. Adding pressure will easily distort the thin sheet or damage the embossed ribs. I ended up sandwiching the wing between two kitchen sponges, then two hard planks to keep it straight and only then clamps. Results were ok, but I need to practice this For the embossing of ribs I got a new tool, the one I had previously made a bit too wide ribs which will be very apparent on the upper wing with its 27 ribs per wing. My new embossing tool had a smaller radius and on top of that a built-in marking functionality: That is 5 thou plasticard, embossing before cutting out. Found those drawing on google image search - no idea about provenance but looked like photos and fitted my drawings like a glove (my drawing had no ribs marked and I would never get 54 lines evenly placed by hand). Continued with struts. The outer wing struts are fat V-struts (more Nieuport inheritance?) so I made them out of plastic. In any case it will be the upper wings that carry the lower rather than the other way around - the contact area for the lower wings is tiny and I couldn’t even fit a dowel how thin they are. This means the upper wings need a sturdy construction. Unfortunately the struts holding it up over the engine cradle are tiny. I had trouble making neat streamlined shapes before (difficult to make them even), so I used a 4th method of making struts: 0.5 mm brass tube, 0.2 mm wire inside, then squeezed it evenly with flat pliers, making an even ellipsoid cross-section. These will also bear the weight of the wings. V-strut and ”tube-strut”: Made a high-tech jig to hold the upper wing. Here I am first dry-fitting the struts. The length of the struts I calculated from the drawings and amazingly enough they actually fit. The aft and fore pairs are different in length since they sit at different angles. Once satisfied I carefully measured the separation distances between the strut attachment points up and down and soldered the middle strut to make a strong N-strut which hopefully will make assembling easy: Here you can also see the result of the wing. I have not cut the trailing edge yet, only marked it, since the fitting will require a lot of manhandling. I have yet to finish the seam along the centreline. Time for painting and assembly! The struts holding the engine cradle are too thick by the way, but I’ll have to live with that. I made them based on model build logs rather than photos of the real thing. Lesson learned Edited December 5, 2019 by Torbjorn 10 Link to comment Share on other sites More sharing options...
Courageous Posted November 30, 2019 Share Posted November 30, 2019 Looking very promising Mr T. Stuart Link to comment Share on other sites More sharing options...
CliffB Posted December 1, 2019 Share Posted December 1, 2019 This is looking so nice. An incredible choice for a scratch-building project. Cheers Cliff Link to comment Share on other sites More sharing options...
bigbadbadge Posted December 1, 2019 Share Posted December 1, 2019 Great work and again some very useful information . What a lovely model, and the engine is exquisite. A big Wow from me. Keep up the good work All the best Chris Link to comment Share on other sites More sharing options...
DMC Posted December 1, 2019 Share Posted December 1, 2019 Excellent, Torbjorn. Always learning from this thread. Dennis Link to comment Share on other sites More sharing options...
pheonix Posted December 2, 2019 Share Posted December 2, 2019 Very impressive. I have found that with items such as struts a compromise has to be made between accuracy and strength: sometimes they are not true to scale but they are there to do a job as well as look nice! P 1 Link to comment Share on other sites More sharing options...
Torbjorn Posted December 2, 2019 Author Share Posted December 2, 2019 (edited) Thank you, guys. Pheonix, yes, although I omit details I can’t get to scale, the absense of struts would have been too conspicious. Metal tube seems promising though, I think I will order a mixed set of brass tubes of various diameter if I am to do this sort of thing again. Edited December 2, 2019 by Torbjorn Link to comment Share on other sites More sharing options...
Torbjorn Posted December 3, 2019 Author Share Posted December 3, 2019 By the the way, found an article in Flight international from 1918 (open archive here: https://www.flightglobal.com/pdfarchive/view/1918/1918 - 0099.html?search=macchi m.5). Note what constitutes a steep climbing angle of a fighter in the early days of flight: 2 Link to comment Share on other sites More sharing options...
Torbjorn Posted December 4, 2019 Author Share Posted December 4, 2019 (edited) No update - apologies! - merely a note to self. Insignia colours used (Vallejo): Red 70.957 green 2x 71.124 + 1x 71.006 Wings (linen). First grey primer, followed by Hemp followed by (incomplete coverage) Aged white. Edited December 7, 2019 by Torbjorn 1 Link to comment Share on other sites More sharing options...
Brandy Posted December 5, 2019 Share Posted December 5, 2019 Very nice! I do like the way you tackled the top wing, it looks excellent. Ian 1 Link to comment Share on other sites More sharing options...
Torbjorn Posted December 5, 2019 Author Share Posted December 5, 2019 (edited) Thanks - unfortunately the underside became less pretty after I used a bit too strong clamps: there is an ugly imprint Current state. Added radiator (made from 2 push molded pieces and a crank from soldering together brass rod and tube and assembled. Also added rigging for the engine cradle since that would be difficult later. The X-shaped wires should meet at those horisontal bars, so I simply tied them together around the bars: Edited December 5, 2019 by Torbjorn 7 Link to comment Share on other sites More sharing options...
pheonix Posted December 5, 2019 Share Posted December 5, 2019 The engine and cradle look very good to me - I especially like the radiator. I also like your method of ensuring that the rigging wires crossed at the horizontal bars - works every time!! P 1 Link to comment Share on other sites More sharing options...
Torbjorn Posted December 9, 2019 Author Share Posted December 9, 2019 Slow going, waiting for layers of paint to dry. The wings have the standard Italian red and green indersides, otherwise linen. A metal plate protected the wing from hot exhaust; I made it in the simplest way possible, plumber’s alu tape. Control horns from beer can. I also managed to put the ailerons the wrong way, so now I have to try to move the control stick the other way. 7 Link to comment Share on other sites More sharing options...
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