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Rob's F-86F NASA 228 research aircraft build


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screenshot 2019-12-06 at 10.42.18.jpegnasa 228.jpeg

This is the version I have chosen to model my build on. An F-86F that was used by NASA at their Ames research facility to investigate boundary layer control. This was the first flying aircraft they used (they did some wind tunnel testing before) and was in service with NASA from 1953-65. I have searched the internet and can find just one picture of this plane in a NASA history book from 1999 and its black and white! But the colours used by NASA are well documented elsewhere and some computer flight sim artists have made up digital versions, one of which looks pretty accurate to me.

This is my first PSSA mass-build so here we go.

Edited By robk on 06/12/2019 11:24:25

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Here is progress until last night. Waiting for some MG servos to arrive from HK today and will try and get them in over the weekend. Hinge blocks and spar webs in place added. I have a lot of clips!

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Edited By robk on 06/12/2019 11:18:40

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screenshot 2019-12-05 at 18.48.04.jpegHere are a couple of digital renderings (paintings!) of what it might have looked like. The artist has decided two is better than one but there was actually only ever one aircraft with this scheme: NASA 228. He/she also left the gun ports in which NASA obviously removed - this was a civil aircraft! The big long spike at the front (presumably for airflow sensors) is also missing. Not sure whether to incorporate that on my model. It would have to be a knock element held on with magnets, and then it might not stay put in the airflow. Even so might be a bit dangerous in case of an accident...

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Edited By robk on 06/12/2019 11:20:10

Edited By robk on 06/12/2019 11:23:02

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Took a bit longer than I thought but I finally decided on a servo installation. I like to be able to remove them easily so these will slide in from the underneath into balsa and ply housing. Plastic mouldings from SLEC screwed into the wing into ply through the balsa surface will protect the servo arms and hold the servos in place. The pictures tell the story really..

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Marking out the servos.

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Thin ply glued to the inside of the balsa skin. Hard balsa bearers (strengthened with cyano where the servo fits)

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Outside of the wing. These are the plastic mouldings I am using.

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Inside the wing.

Edited By robk on 09/12/2019 20:26:37

Edited By robk on 09/12/2019 20:29:27

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Quite agree with Andy Rob. We have tried various pointy bits, guns etc for scale but they all get ripped off either in flight or more likely in heather landings.This was true of the A4 Skyhawk fuel probe, and the long Hurricane wing guns. Static display only agreed.

Good to have you along. Where are you building and where will you fly - any chance of you joining us in June at the Orme?

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Martyn - the mouldings come from SLEC - they come in small and large and these are small.

Yep - Andy and Pete, the giant spike at the front would be a real health hazard. As you say a detachable one is a possibility... I fly from the Orme but have only been to one PSSA meeting so far - the most recent one when I picked up my kit from Martin. Great fun. The June date is in my diary for sure.

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  • 3 weeks later...

img_1602.jpegBit of a hiatus over the last few weeks due to a brief trip abroad and the Christmas festivities, however, its moving again now... covering the top of the wing after connecting my servos up and making sure they work (though I can change them if one goes belly-up). I have since done the shaping of the leading edge, made up the tip blanks and the ailerons and flaps. By the way - the different colour of the balsa on the top is my fault. I under ordered by one sheet what I needed for this job from SLEC. The last piece they sent me was considerably lighter than the others (all were supposed to be medium) so I had to go with what I had in stock which turned out to be a bit harder but at least both sides will balance a bit better.

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Edited By robk on 27/12/2019 19:44:12

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Just finished off the wing including a first sand to shape. I have noticed that the ailerons on the full-size go to the wingtips although the plan (and my build as is) shows they do not. Easy to fix but I will put a question on the Gamma build site for Martin.

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Here is the wing pretty much finished except for control surface connections.

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... and so I have moved onto the fuselage. The frame/stringers took a bit of fettling to fit right. I had to pin it all down firmly to stop warping. Then onto the cladding of the frame. It took me a few tries before I got a system that worked. Some people seem to say wider planks can be used but that didn't work for me so back to 6mm wide ones. I tack these in place along their length with cyano then when I have a bunch done dribble superphatic in the long joints - seems ok so far. Took quite a time and a lot of glue mind. Anyway I will take it off the board now leaving the gaps on top and bottom, and do the other side. The gaps will be useful for fixing the two halves together (not forgetting inserting the various bits such as the battery box and wing bolt mount). I will fill in the gaps after assembly.

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Edited By robk on 03/01/2020 19:26:10

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  • 2 weeks later...

The second side of the fuselage build went much quicker and the planking job looks better too. Here are the two sides which fit together pretty good - only a little bit of fettling required.

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Edited By robk on 12/01/2020 18:45:26

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Now to the insides. First up is the battery box and on-off switch. I know the gamma model has used a magnetic switch but to save twenty-odd quid and because I like to feel a click, Im going for a traditional switch concealed in the nose. Its a black switch and the air intake will be painted black inside so it should be invisible. I had thought of making the entire nose removable allowing the battery to be inserted and removed from the front but decided in the end to leave the main parts of the design intact. So my switch fits into the battery box with some tough semi compressible foam infills to protect it from the four-cell NiMH battery which will slide down into the battery box from the middle of the fuselage before I put the wings on. The switch will turn the battery on and off and I will also have an LED battery condition meter under the canopy.

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Edited By robk on 12/01/2020 18:44:55

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  • 2 weeks later...

Had a couple of weeks off the Sabre putting a Wild Thing together - done now and just waiting for a nice wind at the Orme or similar. So back to this one. Time to do the tail assembly and control system. Started with an easy bit, assembling the tail surfaces. I just got some 12mm thick medium balsa rather than gluing two 6mm sheets together.

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Edited By robk on 26/01/2020 17:43:00

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I have also installed the all-moving stabiliser control runs and the servo mount. I am not going to have a rudder servo - its a scale aircraft for me not an aerobatic one. I thought I might be able to fit a torsion rod but the stabiliser control system is in the way so it would have been a pretty obvious snake or wire loop system which is a bit early 20C for a jet! We will see if it flys ok. Fingers crossed.

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Edited By robk on 02/02/2020 17:41:08

Edited By robk on 02/02/2020 17:44:23

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Constructed the cockpit area (after joining the halves together). I glued in the fin first, making sure the elevator control runs freely. I trimmed the canopy first to see how it would fit and tried it in place as I built up the fuselage.

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