Simon Chaddock Posted August 18, 2017 Author Share Posted August 18, 2017 An initial bit of the underside painted. Really a bit of an experiment to explore what sort of surface finish can be achieved and how heavy it is likely to be using Scola water based (foam safe) acrylic paint. The white Depron underside of the wings only need one coat but the planked fuselage areas really need 2 or maybe 3 with each well sanded to hide the plank edges. So far so good. Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted August 19, 2017 Share Posted August 19, 2017 Nice workmanship, And good luck with the maiden. Steve Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted August 21, 2017 Author Share Posted August 21, 2017 Painting is going very slowly largely due to the need to let each coat dry hard before attempting to sand out the imperfections but its getting there slowly. The reason the outer panels have not yet been painted is I have identified a bit of a problem - one wing has a couple of degrees incidence than the other! I thought I was very careful when I glued it all together but obviously not. It looks a bit more than I could reasonably expect to 'twist out' so I fear a wing outboard of the boom is going to have to be cut off and re fixed or possibly both as it would reduce the degree of 'adjustment' required. Still thinking about the best way of doing it. Edited By Simon Chaddock on 21/08/2017 22:57:28 Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted August 21, 2017 Share Posted August 21, 2017 Looks fantastic Simon. Quote Link to comment Share on other sites More sharing options...
Andrew Price 2 Posted August 22, 2017 Share Posted August 22, 2017 Doesn't it just!! Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted August 28, 2017 Author Share Posted August 28, 2017 After much thinking I think i have successfully 'cured' the wing incidence problem. By completely cutting about 40% (from the tailing edge) of the RH wing just out board of the boom I was able to lift the trailing edge by 2 mm which in effect 'twisted' the whole wing thus reducing its incidence. The wing skin was simply then glued into its new position. Painting started on the outer panels. As the majority of the strength of a monocoque wing is generated by the first 60 % of the wing chord this 'surgery' does not appear to have weakened it significantly. Hopefully any residual unequal lift will now be within the capability of the ailerons for the maiden and can be subsequently overcome by judicious local wing twisting and the application of a bit of heat. Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted August 28, 2017 Share Posted August 28, 2017 I was going to say that it looks as if you've cracked it, but thought again when it sunk in that cracking it was the way you fixed it! Looks as if you've sorted it anyway, I'm sure it will be fine. Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted August 31, 2017 Author Share Posted August 31, 2017 At last the battery has arrived so with a bit judgment and guess work this is about the required position. A bit further forward than I had imagined. The intention will be use the radar operators "coal hole" as the battery hatch with the battery inserted and slid forward into a box built into the nose. Well that's the plan! Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted September 2, 2017 Author Share Posted September 2, 2017 According to the weatherman today Saturday was going to be ideal for a maiden so I rushed to complete the Sea Vixen enough to fly. Any further detail can wait! I took this picture a 9:30 am just before leaving for the field in case it might never look like that again ans i was not far wrong! The first flight lasted no more than 2 seconds. It just rolled over into he ground. This was the result. Nose severely crushed - the picture is after it was pulled back into shape!. The nose of the LH pinion tank was broken off. It was a school boy error. I had to reverse the aileron servo but I forgot to reverse the gyro as well! So with a bit of fiddling with the Tx and struggling to actually see (no glasses) the tiny dip switch on the Rx it actually flew quite well despite the damage. Video next time. . Edited By Simon Chaddock on 02/09/2017 19:01:10 Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted September 3, 2017 Author Share Posted September 3, 2017 Just to complete the story the maiden damage is now all repaired and repainted. And a bit of canopy detail added. The only problem is wind (gales) and rain forecast! Edited By Simon Chaddock on 03/09/2017 14:16:48 Quote Link to comment Share on other sites More sharing options...
Mowerman Posted September 3, 2017 Share Posted September 3, 2017 Hi Simon sad about the first flight . Happy to see you repaired it so quickly Looking forward to the video Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted September 4, 2017 Author Share Posted September 4, 2017 A rather poor heavily edited video if its second flight. White underside against a white overcast meant that for over half the video there was nothing to see! And the landing was a bit of an "arrival" but no damage. Edited By Simon Chaddock on 04/09/2017 14:03:28 Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted September 5, 2017 Share Posted September 5, 2017 Great result Simon. Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted September 6, 2017 Author Share Posted September 6, 2017 Thanks Colin The bit that I am most proud of is not the build, or even the fact that it flies, but my guess at the CofG position! Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted September 6, 2017 Share Posted September 6, 2017 ... I presume your 'guessing' did it again, Simon. ... not only for the CoG but also the drawings, 3D printing, cutting, gluing, planking... ... another mega-great 'guess-chievement' anyhow. Congrats Cheers Chris Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted September 6, 2017 Share Posted September 6, 2017 How close is the c of g to 50% of mean chord Simon? Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted September 6, 2017 Share Posted September 6, 2017 Looks well Simon. Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted September 9, 2017 Share Posted September 9, 2017 Just noticed I said 50% mean chord, I meant root chord. Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted September 10, 2017 Author Share Posted September 10, 2017 Colin I did not actually measure the CofG but simply set it to where it 'felt right' in my hand! With the intake at the front and a fairing at the rear the true root chord is rather hard to measure but the red line shows where the CofG currently is. If leading and trailing edges are extended to the fuselage center line it looks like the CofG would be quite close to 50% chord. Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted January 20, 2020 Author Share Posted January 20, 2020 There is a bit more to this story. Although I had 'tweeked' the wing to balance the wing incidence L to R before it was finished in fact there was some still present. The second flight in the video above required virtually full aileron trim to keep 'wings level'. In such a configuration I feared any flight close to the stall would at best be interesting or at worst result in a serious crash. I could easily see the problem, the geometry of the inlet duct was different! To correct it was going to require some pretty major surgery. I just did not have the heart to cut up a just finished model so it was left hanging on the wall 'for later'. 'Later' actually arrived after nearly 2 years - June 2019! The major surgery required the left wing to be cut completely off just inside the left boom. A narrow 'slice' cut out of the bottom surface of the LH inlet duct and it all reassembled with much masking tape to hold it all in the correct position until the glue set. One advantage of thin Depron is that when a structure is 'bent' into shape over time it permanently deforms so virtually eliminating any residual stresses. It now flies quite well and even better when you remember to switch the 'stab' on! You can hear the 'click' at 0:17! Still really only a 'fair weather' flyer but it looks the part and makes a rather satisfying 'whine'. Quote Link to comment Share on other sites More sharing options...
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