Phil Cooke Posted March 27, 2016 Author Share Posted March 27, 2016 Happy Easter everyone! I managed to get some work done on the A-4 in between the Easter Egg Hunt with the kids this morning and the family meal later in the day... Snakes On a Plane! I don't normally like using snakes but the A-4 layout lends itself perfectly and it was proven to work very well on the prototype. First job is to trim the rear of the fuselage square to the correct length to aid positioning of the snake exit. It should exit the top sheeting at an oblique angle just behind the fin post and just ahead of F8. With a good fit at the rear you can consider how the snake outer is to be retained at the front. I've used 2 braces, cut from 1/2" sheet sized the same width as F5, against which they will sit. The snake will fit snuggly into the central grooves. The height of the braces is dependant on your servo and the type of horn fitting you want to employ - Ive used a small ball joint to aid ease of movement. This sits the snake 1/4" higher than the servo arm. Dry fit everything until you've got a good alignment, then glue the braces in position using wicking cyano. Epoxy the snake outer into the groove either side of F5 and I used a small piece of 1/32" ply to cap the top side, locking the snake in position. Add some epoxy to the rear exit on the inside and outside to ensure it is well retained at both ends. Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted March 27, 2016 Author Share Posted March 27, 2016 With the snake fitted internally we can complete the basic fuselage assembly by adding the lower 1/2" balsa sheet rear of the wing. Cut the forward facing edge with an angle so the front face is vertical when in position - this will aid the wing fit later. Quote Link to comment Share on other sites More sharing options...
Andy Meade Posted March 28, 2016 Share Posted March 28, 2016 Lovely and accurate as always chap Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted March 28, 2016 Author Share Posted March 28, 2016 I've added F9 at the rear, its an end cap effectively, cut from 3/16" balsa and made to accept the exhaust tube which in my case (yes Pete, more girly moisturiser talk!) is a 42mm O/D bottle cap from a Liz Earle moisturiser. I like these as they come pre-painted in chrome! Anyway, make a hole to suit your chosen exhaust tube and align that centrally on the back of the fuselage once you have trimmed the back all co-planar. Et voilà!! There you have the exhaust tube for your Pratt & Whitney J-52 turbojet. Needs trimming to length so only the chrome part sticks out proud! Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted March 28, 2016 Author Share Posted March 28, 2016 Having positioned the snake for the elevator servo sat against the floor (or roof) of the fuselage it needed some hardwood bearers fitting to install the servo onto later. I made 2 longeron bearers from hard 1/2" balsa sheet and machined notches into them to accept the hardwood cross bearers which were sized just under the internal width of the fuselage to aid fitting. The longerons sat up against the top of the triangular section in the roof of the fuselage, making alignment easy. Longerons glued in position using PVA and medium cyano for a fast grab, the hardwood cross pieces are shown here dry fitted prior to mixing a little 5 minute epoxy. Quote Link to comment Share on other sites More sharing options...
Steve Houghton 1 Posted March 29, 2016 Share Posted March 29, 2016 I couldn't motivate myself today to continue the A4 build as I'm feeling a little under the weather, so I've been checking out the Typhoon and ensuring that the servo does in fact release the two bombs when I flip the switch, and reminding myself which TX switches do what. I've also been doing a little work on the Lightning and modifying it by fitting a switch and adding an external method of switching it on & off, as removing the wing each time is a real pain in butt. Hopefully I'll get a chance to fly it next month as I haven't flown it properly yet. Batteries are being cycled also. And as I'm not camping this time, I should have room in the car for the camping stove to make a fresh cuppa. Ahhhhhh Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted March 30, 2016 Author Share Posted March 30, 2016 A bit more progress as the basic fuselage assembly approaches completion... Before fitting the intake formers A1, A2 and A3 it's important to sand the top sheeting flush with the fuselage sides keeping all the corners square for now. It was a good day for sanding outdoors here today, so I tidied up all the edges top and bottom rear of the cockpit, you start to form some interesting shapes on the top surface. With the sheeting flush and square I added the intake formers with CA, they need to be perpendicular to the centreline, not the fuselage side (certainly not A1 anyway, where the fuselage curves in towards the cockpit). With the formers in place I made up the intake front blocks. A little fiddly with so many pieces (the laser cutter cannot cut through 1/2" balsa so the woodpack relies on us laminating 1/4" sheet) - Ensure you make a left and right handed pair as they are not quite symmetrical! With those setting and with my modelling slot fast running out the bench gave way for another airframe in need of cycling overnight prior to the start of the season in just over 2 weeks time! It's Tonka time! Quote Link to comment Share on other sites More sharing options...
Steve McLaren Posted March 31, 2016 Share Posted March 31, 2016 I am impressed! Not just by the quality of the build Phil, but the by the almost daily reports! You seem to be working to a different deadline than the rest of us! Or am I just leaving it too late again? Hope to get mine started this weekend. What news of the 2nd Tonka? Quote Link to comment Share on other sites More sharing options...
Andy Meade Posted March 31, 2016 Share Posted March 31, 2016 Yeah Phil where's Tonka 2? :D Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted March 31, 2016 Author Share Posted March 31, 2016 Just trying to do a little each day Steve, you'll be surprised how quick it goes together with the woodpack once you're underway, I look forward to seeing your blog develop! Second Tonka did get a little bit more work done on it since Christmas, but my aim to have it flight ready for April has failed with all the other mods on other airframes I've done recently... but will have ready for May or June event. Quote Link to comment Share on other sites More sharing options...
Peter Garsden Posted April 1, 2016 Share Posted April 1, 2016 Brilliant News Phil. I showed Jan your Liz Earle bottle top you used for the jet outlet, and guess what. She uses it as well and has an identical top which I can use - result! I will haven not only a scale jet but a very smooth moisturised face as well! 1 Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted April 2, 2016 Author Share Posted April 2, 2016 That's what we like about you Pete, setting the standard, in model fidelity and Mens skin care Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted April 3, 2016 Author Share Posted April 3, 2016 Time to put the fin, rudder and tailplane together. I'm keen to replicate the characteristic rudder stiffeners as in the photo below (copied from an excellent plastic kit review on ScaleSpot.com **LINK** to improve the models scale appearance. Because of this I will be making the rudder up from 3 laminate sheets, a central 1/8" balsa core with a carefully cut balsa laminate each side, these will be sanded down to zero thickness at the extreme Trailing Edge once glued to the core resulting in a 1/8" T/E thickness as required. Edited By Phil Cooke on 03/04/2016 11:51:40 Quote Link to comment Share on other sites More sharing options...
Chris Barlow Posted April 3, 2016 Share Posted April 3, 2016 I've still not started but was also thinking of a way to replicate the rib effect of the rudder since it's a very distinctive feature. Quote Link to comment Share on other sites More sharing options...
John H. Rood Posted April 5, 2016 Share Posted April 5, 2016 And for the Skyhawk disciples who are building the early variant, the A4D-1, the rudder structure lacks that refinement... for example, in the photo here is the prototype taxiing in the legendary high desert heaven of Edwards AFB. Note the smooth rudder panel... and that EPIC nose probe! Quote Link to comment Share on other sites More sharing options...
Andy Meade Posted April 5, 2016 Share Posted April 5, 2016 Definitely the best looking, imho! Quote Link to comment Share on other sites More sharing options...
Steve Houghton 1 Posted April 5, 2016 Share Posted April 5, 2016 That's because you're like a Magpie Andy, you like shiny things Quote Link to comment Share on other sites More sharing options...
John H. Rood Posted April 5, 2016 Share Posted April 5, 2016 A bit better view of that early rudder panel config... this is an A4D-1... Quote Link to comment Share on other sites More sharing options...
Steve Houghton 1 Posted April 5, 2016 Share Posted April 5, 2016 The ribbed version could be a bit of a challenge for those of us covering in shrink film! Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted April 5, 2016 Author Share Posted April 5, 2016 Yes, covering it will be impossible with film. Im planning to glass my airframe and the rudder (with all its detail) might just get a few coats of resin and talcum powder prior to a good primer fill then paint, as opposed to trying to glass it with cloth... Quote Link to comment Share on other sites More sharing options...
Andy Meade Posted April 5, 2016 Share Posted April 5, 2016 Glass and vac-bagging it would work I guess? A bit much though just for small rudder that's not even used ...or I could 3D print the rudder Edited By Andy Meade on 05/04/2016 14:55:49 Quote Link to comment Share on other sites More sharing options...
Steve Houghton 1 Posted April 5, 2016 Share Posted April 5, 2016 Do we know why McD decided to flute the rudder like that? Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted April 5, 2016 Author Share Posted April 5, 2016 ...just to make it more difficult for modellers in the future I think... Quote Link to comment Share on other sites More sharing options...
Mark Kettle 1 Posted April 5, 2016 Share Posted April 5, 2016 Rudder Fluting - Rudder made 'inside out' ribs on the outside .....to cut out vibration and rudder flutter from model A4D-2 - A-4B onwards :- from link, 1px 0.35em no-repeat transparent;">Improvements incorporated in the A4D-2 (A-4B) Skyhawk were a stronger, "inside-out" rudder construction; a pressure fueling system with a probe for air-to-air refueling; external fuel tanks; stronger landing gear; additional navigation equipment; an improved air-to-ground ordnance delivery system; and an externally-carried "buddy store" package for air-to-air fueling of other aircraft. Note the rudder has supporting ribs on the outside, rather then inside. This change was introduced as a temporary fix for "rudder flutter" discovered during testing of the A4D-1; but remained as a fixture of all future Skyhawks. **LINK** http://a4skyhawk.org/content/douglas-4-skyhawk-production-history Edited By Mark Kettle 1 on 05/04/2016 17:24:18 Edited By Mark Kettle 1 on 05/04/2016 17:26:08 Edited By Mark Kettle 1 on 05/04/2016 17:26:31 Edited By Mark Kettle 1 on 05/04/2016 17:27:11 Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted April 14, 2016 Author Share Posted April 14, 2016 Jester's arrived and is seen checking out his new office for size. Real Model Pilots manufactured 1/12th scale jet jockey. Just needs a lick of paint. Quote Link to comment Share on other sites More sharing options...
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