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The Last Skyhawk


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Thanks guys. It's not quite there yet but with a few tweaks to the plug I'll be happy with it!

A couple more bits this evening starting with the printing and cutting of the decals. For the lettering I used white and black vinyl on a roll and for the insignia, flags, etc were printed onto decal paper first. The printed decals still need sealing with clear gloss bit I'll let the ink harden off first.

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I also made a couple more trinkets for the tail. This A-4 won't be getting shot down by any SAM's on the Orme!

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Whilst at that end I painted the underside of the exhaust shroud.

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Peter, there's going to be trinkets everywhere. Just hope they stay on long enough for at least the first flight!

Andy, the decals will be sealed with a couple of coats of Tamiya X22 clear gloss. First coat will be a light mist coat with the airbrush to seal the surface and hopefully prevent the inks from smudging. I will be doing a trial run with a test sample first though! My printer is just a HP Envy 5644.

Steve, you're not alone with choosing the right fonts! I can spend hours agonizing over which one looks closest and have even used 2 fonts because one letter of one font just didn't look right so I pinched one from another font!

Thanks Harry. The vac former is something I've wanted to build for a long time just never got round to it. There's probably a dozen things I want to make with it so it'll be getting some use after September!

So with just over a week left time is getting a bit tight and frustratingly even with a few hours in the workshop tonight there doesn't seem much progress to show!

I started by spraying the canopy plug with filler primer so it could dry ready for fine sanding. I'm very conscious that Matt will be needing a canopy ASAP so I hope to get 2 better canopies done Thursday night and get his off in the post for Friday.

I also had a bit of a play with ideas for refueling probes and may have come up with an acceptable solution that won't snag and snap too easily!

I also gave some extra though to the switch problem. Normally I would just mount a switch over the wing where it can't get touched by launching fingers but quite a few people have mentioned making it discrete. My solution was to mount the switch verticaly inside the fuselage and operate it with a pushrod from above.

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The protruding part of the pushrod is mounted into the blade antennae on top of the electronics pod.

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The blade was drilled with a 2mm drill to within 3mm of the top and the pushrod roughed up with sandpaper and glued into the hole with medium cyano.

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The pushrod can be screwed into the clevis until it is tight to the pod with the switch off. There is a cut out in the pod the same shape as the blad to allow it to be pushed down to switch on and this will also ensure the blade and pushrod cannot rotate in flight. The blade was then covered with black film.

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I have also painted a red line at the base of the blade which can only be seen when the switch is off. Hopefully this and a strict control check before launch should prevent any embarrassing free flight incidents!

I have also painted the red intake warning band ready for applying the danger decals then they can all be sealed with acrylic gloss.

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I used an aerosol can to cut two semi circles from black solar trim for the intakes themselves.

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I still need to mix some grey paint to blend in where the grey meets the white with the airbrush. The blue line you can see is where the grey was marked for positioning the white but unfortunately it bled through when heat was applied!

Last job was to sand the canopy plug with 400G wet and dry and apply a second coat of primer. I'll take it to work with me for a final sanding and a coat of gloss so it should be ready for use by the time I get home.

Like I said not much to show for around 4 hours work but not much left to do now. Elevator servo to fit, RX to install and set up and a check on the balance. There should still be time to mess about with the drop tank!

 

Edited By Chris Barlow on 01/09/2016 02:56:04

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Looking great, I especially like the switch and the glow in the exhaust. Mine won't be finished in time to take it to Manilla slopefest as I have been working too often. but I am going with some other gliders and will submit some pics on my return. good luck with your maiden (shouldn't be far off now) and i hope you get to the Orme. cheers, Graham

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Steve, if it becomes a problem I can always turn the switch around and make it pull for on but TBH I think I would prefer a flat battery to my Skyhawk flying out to sea switched off! surprise

Lots of little bits to finish before it's ready to fly. I made a wood plug for the 150 gallon center line drop tank, split it in half and used it as 2 plugs in the vacuum moulder. I used a sheet of thick plastic to mould the two halves and when cut out glued both halves to a 1/4 sheet balsa inset inside with epoxy.

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A slot was then cut out to take the drop plate which was epoxied in and after a coat of filler primer it is now drying between coats of white gloss.

I also came up with a solution to the refueling probe. After seeing Peters broken probe at the last meeting I wanted to make one detachable if landing in the rough but strong enough to stay on in flight. The solution was to bend a brass tube to form the projecting part, file a flat in the tube, fill with balsa and cyano in a flat magnet.

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An identical flat magnet was then cyano'd into a recess cut into the fuselage side. Both magnets are flush with the probe side and fuselage.

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The probe then simply sticks to the fuselage and also lines itself up. In the event of it snagging the probe should just ping off. I may tether it with some fishing line to avoid loosing it!

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The remainder of the re-fueling pipe will be made from shaped balsa. The brass tube has an additional benifit in that a little nose weight is required for balance.

Speaking of weight I'm currently at 2lb 3oz without the drop tank which is an additional 47g (1.6oz) ready to fly. This will increase a little with a bit of touch up paint

Edited By Chris Barlow on 04/09/2016 18:06:15

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Not much time left but nearly there!

I soldered a 4mm bullet connector to the end of the re fuelling tube and covered the joint with heat shrink tubing to get something that resembles a probe shape, gave it a lick o' paint and clipped it on. The rest of the pipe was made with balsa and covered in film.

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The paint's not an exact match but I'll probably have to sort that out later!

I also made a cover for the elevator linkage from ali sheet which is fixed in place with a single screw to enable access. Still needs a lick o' paint!

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And fitted the "hot dog" antenna on top of the fin.

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Last job was a trial fit (and drop) of the 150 gallon drop tank. This too still needs "a lick o' paint" but is nearly there.

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A bit more work with minor details and it's now done. There are many other bits I'd like to do but they'll have to wait!

I've added some panel lines which I'll go over with an air brush after the weekend to add in some weathering and depth. I also cut the white film back about 2mm at the nose to remove the blue pen line and have painted the detail on the nose of the drop tank.

My daughter usually models my planes for me but with the approaching rain was very reluctant today, even after tempting with money, so my wife was recruited for the photographs!

I got her to smile for the first few seconds

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Which quickly faded after a few shots!

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Vicky was now showing appreciation of my direction in holding the model and was working on her facial expressions to compliment the model.

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At this point she realised neither Tom Cruise, Val Kilmer or Tom Skerrit were in the pilots seat!

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So she lost interest, got very bored and fell asleep!

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Now to see if it flies!

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Hi Chris. Yes the canopy stuck well after 48 hours even with the Heath Robinson clamping arrangement so I'll definitely be buying a lottery ticket tomorrow!

Peter, why do you torment me so? wink I'm looking at W to SW winds on XC Weather so I hope that'll reduce the risk of it getting wet if it goes wrong! Maiden will be with the Centre line pylon attached but can't wait to try the drop tank later!

Phil, embarrassing admission here. The wife and I only knew three of the national flags for certain and had to search Google for the rest! blush

As long as it looks like the photograph at the top and flies as well as the prototype and Peter's I'll be happy.

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Thanks John. The missus will require further training on serious presentation of men toys!

Final update on the Last Skyhawk!

I'm pleased to report that the maiden went very well, just needed less expo and more travel on the elevator. Real fighter jet performance in good air with smooth, axial rolls and a nice scale speed. An absolutely exhilarating joy to fly. All three flights were with the drop tank attached to increase the weight and this was successfully released before each landing.

Some amazing photos here by Matt Jones and an excellent sequence showing the tank drop. A short video from Sunday of some A-4 and PSS action here too.

The Last Skyhawk also won an award for the most innovative build for a combination of magnetic refueling probe, drop tank and for being an "M" variant with a different canopy and electronics hump. I was equally surprised and embarrassed and will put the prize to good use in the form of what I hope will be another unique and fun PSS build discussed on the slope on Sunday!

So in summary, and interesting build, fantastic flyer and a great community on the slope with an exceptionally high standard of models everywhere.

What's not to like about PSS! laugh

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