Martinsson Posted February 23, 2009 Share Posted February 23, 2009 Hi again, "You may very well be right. It's just that I work with end-to-end dimensions. The bounder layer exit hatch (you're talking about the spill on the nose ? I remember someone saying that it's a radar cooling vent) and AOA vane base are likely to be misplaced and misshapen (the Academy boundary air/radar cooling spill definitely is) to me." I agree that Academy has at least mis-placed the spill hatch on the nose and the AOA meter diamond. But I still think that is because the nose is too short. However, I think I understand exactly how you measured the thickness of the nose and I tried a new technique to verify your theory. I used a good profile photo of a MF and drew a ling along the lower edge of the canopy. This line slopes downwards and meets the nose at the boundary layer exhaust. It passes just a bit underneath the front edge of the windscreen. When I did the same to the kit parts, the line doesn´t meet the nose until just before the intake lip. There is more of the nose above the line on the kit compared to the photo of the MF. That indicates that you are right, the nose is about 1-1,5 mm too high at the front end of the windscreen. It would also seem, from this measurement, that Academy compensated for this mis-match in front of the windscreen by sloping the nose downwards quite heavily the last 8 mm behind the intake lip. If this is correct, then the whole intake ring should be lifted up about 1-2 mm. Then the line following the canopy sill will meet the nose at the proper place. It will also make the nose taper correctly on the underside as well as the up side, when viewed in profile. The kot nose doesn´t taper much on the underside. From this measurment it looks like the canopy is too short while the windscreen is too long (X-axis). This is supported by Laurents table. The windscreen should also extend another 1-1,5 mm downwards at the front in accordance with the reduction of nose thickness. The canopy should be long enough to display the "ears" of the ejection seat, the pilots helmet and leave space in front of the helmet before it meets the rear edge of the windscreen. Laurent, would you say that the spine is correct in length? If the canopy need to be stretched, I don´t think the missing 4mm (according to your table that is supported by my photo analysis) will be made up for by shortening the windscreen. Maybe 2mm can be accounted for by the windscreen. Should the spine be shortened by 2mm also you think? Now I actually think I will try to modify the canopy and nose height along with the nose length. Please let me know how it works for you. I have built my own vacform machine so I will try to vacform a new canopy the same way you are doing. I will let you know how it goes! Your table is a bit inconclusive regarding the max and min width of the canopy. Do you think 1mm will be a good average? 5cm on the real aircraft. Best regards Martin Quote Link to post Share on other sites
jaydar Posted February 23, 2009 Share Posted February 23, 2009 I just got this kit in the mail and let me say...Wow! First off, yes i know that the Acad MF is really a Bis, but the amount of detail in the kit is just astonishing, especially for a 1:48 Acad. The panel lines are just the right depth and consistently engraved, and there is a smattering of rivet detail, just enough to look realistic. Of course it comes with the early Atol missiles but it also has the old gunpack and the Gsh-23 gun as well, and the 16 and 32 shot rocket pods are very nice. Surprising is the absence of cockpit decals. Yes, one of a few Academy kits that actually has raised detail in the cockpit! and the ejection seats (a KD-1 and another I don't know) are great looking. And to cap it off the landing gear are multiple part pieces incorporating some rather fragile looking detail linkages. Overall, it makes a great base for a fine-looking 21-93. I want to thank all of the guys on this thread. I have a Mig 21 in the build pile too and like you all I would like an accurate outline. Please continue. Best regards, joe. Quote Link to post Share on other sites
Laurent Posted February 23, 2009 Share Posted February 23, 2009 (edited) Laurent, would you say that the spine is correct in length? If the canopy need to be stretched, I don´t think the missing 4mm (according to your table that is supported by my photo analysis) will be made up for by shortening the windscreen. Maybe 2mm can be accounted for by the windscreen. Should the spine be shortened by 2mm also you think? I didn't check the spine length yet. What I think is wrong is that the vertical front canopy frame is too vertical (too perpendicular to the horizontal frame). Compare the profile of the Academy canopy to a real canopy. It should lie down more on the windscreen so 1-2mm should be sanded from the windscreens flat glass. In fact that could be the only thing to do on the windscreen. I'm at work so I cannot check right now. Your table is a bit inconclusive regarding the max and min width of the canopy. Do you think 1mm will be a good average? 5cm on the real aircraft. The table includes the max windscreen width (1.5cm in Academy kit and ACE Pub drawing) and the spine width at the canopy intersection (1.3cm on all drawings... now that's a concensus !). The thing I intend to do is leave the front part alone and sand 1mm on each side of the rear part. Note that I've done the measurements on the glass part not on the horizontal frames. Edited February 23, 2009 by Laurent Quote Link to post Share on other sites
Laurent Posted February 23, 2009 Share Posted February 23, 2009 I want to thank all of the guys on this thread. I have a Mig 21 in the build pile too and like you all I would like an accurate outline. Thanks for the kind words. I feel like a modelling geek with all those drawings, plastic bits and measuring thingies lying around Quote Link to post Share on other sites
Berkut Posted February 23, 2009 Share Posted February 23, 2009 Thanks for the kind words. I feel like a modelling geek with all those drawings, plastic bits and measuring thingies lying around :( We are all model geeks anyway Laurent. This is indeed a very interesting discussion. Although i highly doubt i will fix any nose problems on my MF, this is interesting to read anyway. Quote Link to post Share on other sites
Martinsson Posted February 23, 2009 Share Posted February 23, 2009 (edited) I think you are right that the windscreen sill should lean more forward than it does on the kit. But the windscrren needs to be shortened at the base too. Look at this photo: http://www.airliners.net/photo/Czech-Repub...next_id=1463947 The side windows in the windscreen are much shorter than the kit parts. And this is good. If the windscreen is shortened a couple of mm, the main canopy will be have to be longer by the same amount. That will be a big improvement for both the windscreen and the canopy. "The table includes the max windscreen width (1.5cm in Academy kit and ACE Pub drawing) and the spine width at the canopy intersection (1.3cm on all drawings... now that's a concensus !). The thing I intend to do is leave the front part alone and sand 1mm on each side of the rear part. Note that I've done the measurements on the glass part not on the horizontal frames." That sounds like a clever solution. But I don´t think you should remove more than 1mm in total from the rear part of the canopy, maybe 1,5mm tops. 1mm in 48 scale equals 5cm in 1:1. If you remove 2mm it equals almost 10 cm on the real jet. That seems to be a bit too much don´t you think? Well, now I have my action plan set out thanks to you Laurent! This is the first time I have really understood what is wrong with the tubby Academy nose. I just need to split my focus between the MiG-21 that I have had in waiting for a solution, and the 1/48 F-86H scratch conversion I´m working on! Thanks for the encouraging comment Joe! Martin Edited February 23, 2009 by Martinsson Quote Link to post Share on other sites
Laurent Posted February 24, 2009 Share Posted February 24, 2009 (edited) That sounds like a clever solution. But I don´t think you should remove more than 1mm in total from the rear part of the canopy, maybe 1,5mm tops. 1mm in 48 scale equals 5cm in 1:1. If you remove 2mm it equals almost 10 cm on the real jet. That seems to be a bit too much don´t you think? I don't know. Probably if a resin copy is to be made because of resin shrinkage compensation. I've sanded the upper nose. Max nose thickness is currently 2.5cm. I'm not sure if I want to go any further. The bounderlayer layer/radar cooling vent oval hole bottom is now almost coplanar with the nose surface. I've started sanding the windscreen locations so that it will fit. I'll have do saw the spine from the front fuselage halves too. Well, now I have my action plan set out thanks to you Laurent! This is the first time I have really understood what is wrong with the tubby Academy nose. I just need to split my focus between the MiG-21 that I have had in waiting for a solution, and the 1/48 F-86H scratch conversion I´m working on! Ok. I'll post some pics when there will be something consistent to show. Laurent Edited February 24, 2009 by Laurent Quote Link to post Share on other sites
Litvyak Posted February 24, 2009 Share Posted February 24, 2009 Laurent, I look forward to seeing that, too. But perhaps the short-looking nose could be right for a Ye-4 prototype?? Quote Link to post Share on other sites
Laurent Posted March 8, 2009 Share Posted March 8, 2009 (edited) I've found an interesting discussion on a Key Publishing forum. The topic started as a discussion about the Famous Russian Aircraft MiG-29 book but it has split in several discussions. One is about the differences between third generation MiG-21s (S/R/SM/M/MF/SMT) and the fourth generation Fishbed (MiG-21bis). http://forum.keypublishing.co.uk/showthread.php?t=86061 The intake diameter of the 3rd gen is supposed to be 87cm, 90cm for the 4th gen plane. 3 centimeters... It's true that the 3rd gen aircrafts seem to have an ogival nose while the 4th gen seem to have a more (parallel) cylindrical nose but I wonder if it's not some sort of optical illusion with the PVD boom, RSBN antenna, differing cone position interfering. I'm still working on the nose + canopy modification. It's long and painful as sanding the top of the nose implies that the whole windscreen area needs to be reworked. The rear Academy fuselage looks weird and I wonder if the remorked from fuselage I'm doing wouldn't fit on a OEZ/KP/Aeromaster kit. Edited March 8, 2009 by Laurent Quote Link to post Share on other sites
Martinsson Posted March 9, 2009 Share Posted March 9, 2009 Hi Laurent, I will read up on the Key Publishing forum thread. Thanks for providing it. I have pictures showing a difference between the bis and S/R/SM/M/MF/SMT jet intake. It is just slight and you describe the difference very well. I am also working on my MiG-21 nose together with my F-86H scratch conversion. On the MiG, I have sanded the nose to shape and I am in the process of gluing the fuselage halves together so I can see if I am happy with the result. The cockpit is just finished and glued in place and I have glued the left nose half together with the left main fuselage half. I did the same on the right side. This ensured a perfect fit between the nose and main fuselage part. If you follow Academy´s suggestion and glue the nose halves and main fuselage halves toegether and then join the nose section and main fuselage, you will end up with a step. I reduced the height of the nose at the front edge of the windscreen about 1,2 mm. That forced me to re-shape the nose in front of the vent. I needed to reduce the height in this area too, to maintan proper curvature of the nose. Not much, maybe 0,4 mm. I also sawed off the nose ring (jet intake) and put in a 1mm extension. Finally, I moved up the nose ring by 0,5mm to be able to sand the nose underside so that it slopes upwards towards the nose ring. Just as the nose slopes downwards towards the nose ring on the upper side. I have also glude a 0,5 mm extension ring in front of the kit nose ring (the one I sawed off). This extends the nose a little bit further and it will also allow me to reduce the intake diameter by 0,5 mm. Since Academy missed the slope upwards on the nose underside, just before the nose ring, I think they designed their nose from bis measurments. Just as they did with the spine. In my opinion, this allows me to correct the nose proportions (a more slender nose) as well as to correct the shapes. I have also reduced the width of the spine, where it meets the canopy as you suggested Laurent. I have made epoxy copies of the windscreen and canopy that will need a lot of work once I am happy with the fuselage. I will publish photos in the In-Progress forum once the pieces have come together and I have something more substantial to show. I will let you know when that happens in this thread. Out for now. M Quote Link to post Share on other sites
Laurent Posted March 17, 2009 Share Posted March 17, 2009 (edited) I'm getting somewhere in correcting the nose and canopy. Pics pretty soon. It looks as if Martinsson is right about the nose being a tad too short (1-2mm). Oh I've mailed Eduard to know when the first MiG is to be released. I've just got the answer Dear Sir,We are planning to release the Mig-21 kit in the spring 2010. Stay tuned. Best Regards, Libor Havranek Webmaster Eduard Model Accessories ltd. Edited March 17, 2009 by Laurent Quote Link to post Share on other sites
David Walker Posted March 18, 2009 Share Posted March 18, 2009 That's good to know. Thanks! I can't wait to see what they put out. Quote Link to post Share on other sites
Laurent Posted March 18, 2009 Share Posted March 18, 2009 Thanks! I can't wait to see what they put out. The thing is I wonder if we won't have to wait longer. The first boxing was supposed to be released in Automn 2009 AFAIK. Quote Link to post Share on other sites
Martinsson Posted March 18, 2009 Share Posted March 18, 2009 Hello, An up-date as promised. Here is a quick drawing of the modifications I did to the Academy MiG-21MF kit. Please remember that the drawing is not to scale. I have a couple of photos that I will publish at the In-Progress site as soon as I get around to up-load them. Anyway, here is the drawing and my take on what needs to be done to the Academy MiG-21 concerning the nose job. My Mig-21 nose profile is outlined in red while the original Academy kit is captured roughly by the black outline. Great news about Eduard´s MiG-21 project. Thanks for sharing Laurent! It would be nice to be able to build more MiG-21 without going through the process of modifying the Academy kit once again! Best regards Martin Quote Link to post Share on other sites
Laurent Posted March 18, 2009 Share Posted March 18, 2009 It would be nice to be able to build more MiG-21 without going through the process of modifying the Academy kit once again! Given the amount of work, it would (or would have been) great to do a resin or vacuform nose (cheaper than resin ?) and canopy replacement. Perhaps it could still sell a bit. A second generation MiG-21 could sell better: I'm not sure if Eduard will release a MiG-21 PF/FL/PFS/PFM very soon... Quote Link to post Share on other sites
Martinsson Posted March 19, 2009 Share Posted March 19, 2009 Hello, I promised to get back with actual photos of my modifications. Well, here it is: http://www.arcforums.com/forums/air/index....howtopic=180594 I still have the canopy to correct but at least I´m ready to glue wings and stabilizers on tonight. Then it is time for the paint shop! Cheers Martin Quote Link to post Share on other sites
Laurent Posted March 28, 2009 Share Posted March 28, 2009 As promised. I haven't worked on the parts for quite a while and on any model kit at all in fact. The front of the canopy has been lenghtened by 2.5-3mm and pinched at the rear. I need to figure out what to do next. Quote Link to post Share on other sites
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