Vitali Posted July 15, 2015 Share Posted July 15, 2015 If your creating masters for someone I wish you'd consider an early boat tail for the Trumpeter F-14A Tomcat! I'd love to do an early F-14A, in VF-1, VF-2 first cruise or even a Test bird. Out2gtcha and allthumbs 2 Link to comment Share on other sites More sharing options...
wardog Posted July 17, 2015 Share Posted July 17, 2015 Rich, once again, awesome attention to detail. The scribing is top notch, especially where the lines intersect. I use the same technique for rivet holes except for the use of the razor blade. Will have to try one out for that purpose as I've been using sandpaper till now and it always makes for a long process. Elmo allthumbs 1 Link to comment Share on other sites More sharing options...
allthumbs Posted January 9, 2016 Author Share Posted January 9, 2016 (edited) Air intakes...they suck! Crude pun aside, these inlets, in particular the interior ducting that channels air to the engine's compressor, are often the bane of many a jet modeler's existence. If the kit manufacture supplies one at all, it's usually a multi part affair requiring tedious filling and sanding to achieve "seamlessness." Indeed, a cottage industry exists to address this very concern, usually in the form of a one piece resin replacement. Recently, one such supplier released a set for the Trumpeter A-6 Intruder. It was discussed and reviewed on this site a few weeks ago...http://forum.largescaleplanes.com/index.php?showtopic=59418. It looks good and will no doubt be a time saver. But, as I had already begun work in this area using the kit supplied parts, I elected to continue down this path, now with the added insurance that if I make a mess of things, a fallback exists (my other fallback is the AMS (by Harold) ground covers http://store.spruebrothers.com/product_p/ams32087.htm . Given the limitations of injection molding, Trumpeter managed to provide a pair of fairly accurate and complete Intakes that include the complex "S" shaped ducting that extends a scale seven feet to engine facings, the latter comprised of a bullet fairing, guide vanes and first stage compressor - not bad, as these things go. Here's a look at what you get... As you can see in the last photo, Trumpeter, true to form, provide whole engines, which can be viewed from below through open access doors, if the modeler chooses. Now, as it turns out the the intakes on the real aircraft are not seamless! Well sort of...to illustrate, here are some pictures of the real deal... These pictures are of EA-6B Prowlers, and while there exist detail differences (more on these later) the basic geometry and design of the air intakes are the same across all versions. Notice in the picture of the removed engine, a 32 inch long cylindrical shroud, dingy white in color, remains attached to the front of the engine. When the engine is re-installed in the airframe, this section slides into the intake trunk creating a prominent (and not-so-aerodynamic) step. Trumpeter depicts this interface, but rather crudely, as seen here... What can done about it? For starters, the cylinder section can be backed out a little (it's designed to insert about 5mm into the main body) so that the dimensions and tapers are more closely matched. This helps some, but the fit is still too loose. Some thin walled brass tubing might do, but I couldn't find the right size. In the end, I decided to enlarge the kit supplied parts. The forward half of the tube was spliced in four places and then spread apart with plastic shim stock, as shown here... After clean up and re-shaping (to help restore a circular cross section), I was able to attain a nice tight compression fit... Next up, the engine facings... Thanks as always for looking, and "Happy New Year" to all my friends and acquaintances on the forum Rich Edited June 15, 2020 by allthumbs Vandy 1 VX 4, Lothar, andromeda673 and 9 others 12 Link to comment Share on other sites More sharing options...
Youngtiger1 Posted January 9, 2016 Share Posted January 9, 2016 Totally awesome work Rich. The last pic shows great result of your hard work allthumbs 1 Link to comment Share on other sites More sharing options...
dodgem37 Posted January 9, 2016 Share Posted January 9, 2016 Real nice. Sincerely, Mark allthumbs 1 Link to comment Share on other sites More sharing options...
ClumsyDude Posted January 9, 2016 Share Posted January 9, 2016 Wow Rich, that's a gutsy and effective solution. Great work! Jim allthumbs 1 Link to comment Share on other sites More sharing options...
allthumbs Posted January 9, 2016 Author Share Posted January 9, 2016 (edited) Thanks Mike and Mark and Jim. I appreciate your kind words! On to the part that really sucks - or squeezes according to the old adage - the compressor section. Of course, looking down the intake, all we see is the first stage in a series of compressor discs, this section partly obscured behind a set of inlet guide vanes and the large "bullet" fairing for the shaft. But a picture (or two) is worth at least a thousand silly words... Note the detail differences between Intruder and Prowler engines: the shape of the bullet fairing, the number of guide vanes, and finally the position of the small air data probes. The heavier EA-6B benefited from the additional thrust of the P-408, as did later Skyhawk variants (the A-4F "Super Fox" and the M/N models). Not surprisingly, most of the "good" engine pictures you see online are of EA-6B's, as these aircraft remained in service through the digicam era. Again, Trumpeter deserves credit for their attempt. They provide separate parts for the bullet cone (well done), the IG vanes (okay, but kind of thick), and the front compressor disc in brass (not so impressive)... Put together, it looks like this... Yes, compared to the reference photos, it looks a bit crude. But, given that these parts, once installed, literally lurk in the shadows, we shouldn't be too quick to condemn. Nevertheless, I set out to improve the look of this area with some scratch building and parts substitution from the spares bin. First off: "the heist." The compressor disc was replaced by a fan section from a Revell 1/144 Boeing 767 kit - it fits just right and even has the correct number of blades - 32 for the "blade counters" among us . Score! The spinner was sawed off and discarded. Next, a groove was scribed into the facing (make sure your circle template is aligned properly - you only get one chance at it!). Into this channel was laid a stretched sprue "ring" that simulates the stiffening devices (“mid-span shroud” in turbine engine parlance) of the real deal. See here... continued... Edited August 22, 2023 by allthumbs Starfighter, Harold, Greg W and 3 others 5 1 Link to comment Share on other sites More sharing options...
Barry Posted January 9, 2016 Share Posted January 9, 2016 Excellent work Rich, serious OOB thinking! :thumbsup: Barry allthumbs 1 Link to comment Share on other sites More sharing options...
allthumbs Posted January 9, 2016 Author Share Posted January 9, 2016 (edited) For the inlet guide vanes, a new "hub and spoke" assembly was fashioned from scrap parts and sheet stock... And the new parts grouped together... more to come... Edited May 29, 2020 by allthumbs Lothar, Vandy 1 VX 4, Harold and 4 others 6 1 Link to comment Share on other sites More sharing options...
allthumbs Posted January 9, 2016 Author Share Posted January 9, 2016 (edited) Thanks Barry! On to some of the more visible aspects of the air intakes, starting with the boundary layer ramps... The kit parts are a little undersized and lack the distinctive bevel design seen in these photographs... After two failed attempts at improving the ramps, I finally hit on a technique that worked. Version 3.0 is a brass and plastic laminate, the former provides strength and rigidity, the latter a more submissive medium for shaping and sanding. Here are the blanks after being cut to shape... The brass and plastic pieces, bonded together with super glue, are block sanded to achieve a square edge... Appropriately sized brass discs were punched from shim stock. Tack glued to the ramps, they provide a sanding template that helps achieve consistent radii for the corners... Another brass template is used to help create the sweeping bevel... continued... Edited May 30, 2020 by allthumbs Greg W, Vandy 1 VX 4, andromeda673 and 2 others 4 1 Link to comment Share on other sites More sharing options...
allthumbs Posted January 9, 2016 Author Share Posted January 9, 2016 (edited) The intake ramps and brass template were placed into a makeshift sanding jig to facilitate the shaping and finishing process... And here are some pics of the finished ramps, the low light of a setting sun accentuating the effect... You can see from the pictures that the ramps are shaped from over-sized blanks. This helped in handling the pieces during the shaping process. I'll cut off and discard the excess material later... Thanks for looking! Rich Edited May 29, 2020 by allthumbs Youngtiger1, blackbetty, Starfighter and 5 others 7 1 Link to comment Share on other sites More sharing options...
LSP_Kevin Posted January 9, 2016 Share Posted January 9, 2016 Crikey, this is amazing work, Rich! Fantastic stuff. Where did you get the mitre sander from? Kev Vandy 1 VX 4 and allthumbs 2 Link to comment Share on other sites More sharing options...
Hubert Boillot Posted January 9, 2016 Share Posted January 9, 2016 (edited) Ingenious solutions and stellar work for the intakes, engine faces and ramps, and great results Hubert Edited January 9, 2016 by MostlyRacers allthumbs 1 Link to comment Share on other sites More sharing options...
petrov27 Posted January 9, 2016 Share Posted January 9, 2016 really outstanding stuff - are these masters for resin casting possibly? allthumbs and Kagemusha 2 Link to comment Share on other sites More sharing options...
Guest Posted January 9, 2016 Share Posted January 9, 2016 Dam Rich, this is some great stuff. I love it....Harv Link to comment Share on other sites More sharing options...
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