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Chris's JP


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The one big advantage of torque rods for the ailerons on a low wing slope soarer is the fact that there are no control/servo horns on the underside of the wing to get damaged when landing (if you have to horns on the top wing surface they are very obvious.

With the width of the JP body you can fit two servos side by side in the wing root, one for each torque rod.

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John, I didn't look at them whilst sanding them round. I just held them in each hand to compare them by feel. Usually works quite well for matching a pair. wink

John A H, I've had a look at your JP & it's just stunning! Yes my control horns are exiting on the top of the wing and I hope that with a black colour scheme and a minimal projection they won't be noticeable after launch.

I'm a little concerned about where the top wing sheeting is cut for the servo exits so made a couple of re-inforcing plates for the openings

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I also re-inforced the rudder with a strip of hard balsa top & bottom to stiffen it up and to prevent it from splitting

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Wings have been joined with the jig shown on the plan and the brace installed. This didn't turn out to be as hard as expected as I cut through the top skin I felt around with the tip of the scalpel for the webbing/spar. Once found I let the side of the blade run along it until I hit R2 then did the same on the other side of R2 up to R3 and the same on the underside. R1 and R2 were then cut through with a modellers pull saw which is like a scalpel but with a saw blade. I trial fitted the ply spar first before running aliphatic glue into the slot to run down the shear webbing (takes a bit of time and patience but does go in) The spar was then pushed through the slot and tacked to the bottom skin with cyano to hold it in place whilst the excess ply was trimmed off. I then set the wing up on the jig again and ran some cyano against the top skin to set the angle. The joint was then bandaged with 2 layers of GF tissue and polyester resin.

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Along with the tip tanks the nose had also been laminated up. This has been glued to F1 with 5 minute epoxy, planed and sanded to shape. Still needs filling and finer sanding yet.

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With enough bits cut/glued or assembled it was time for the obligatory premature assembly to see what she looks like.

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Makes me want to put an RX and battery in and go fly her right now! It's certainly windy enough here!

Edited By Chris Barlow on 24/12/2015 02:23:11

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Chris, good choice of scheme - will be quite easy to do in Solarfilm - always my preferred choice of finish - or Oracover which is expensive but easier to apply with the righ temperature iron 150 degrees C

Looks briliant Chris and well finished - something I never manage - always photograph my scruffy finishes somehow, but as they say it doesn't matter if it flies.

If you need an instrument panel, look on Phil's blog, he has produced one you can print - best on glossy photo paper.

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Thanks Peter/Phil. I was looking around for an instrument panel & that'll save a couple of hours. I've also downloaded a few of the photos in my preferred livery for reference. Will have to sort out the yellow trim and decals soon!

Hoping to escape to the shed in a bit after the kids are all set up with their presents!

Merry Christmas everybody!

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A bit more done over the last couple of days in between setting up the kids laptops, installing software for then and sorting out a new phone for the wife!

I decided to try some Oracover for the black as I've not used it before. I covered the Tucano with some HK black and struggled with it as it was more like plastic sheet than stretchy film and I didn't want the same struggle again. It's still not a stretchy as the usual coloured SolarFilm but better than the HK stuff I have on the shelf!

The wings are covered and the reinforcing plates have blended in reasonably well. I made the aileron control horns from 0.8mm epoxy sheet to minimise drag as much as possible. The servo arm & linkage will still be visible on the ground but I thing you'd be hard pushed to see them in the air!

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The intakes were made from 1/2" soft balsa which makes a lot of dust when sanded on the bench sander to get the basic shape. Final shaping was done by hand and they were also profiled a little to match the fuselage sides better.

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The intakes were shaped as one piece and then the wing section cut out to form the section of the intake to fix on the underside of the wing.

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The wing tanks have also been covered but will need a bit more work to make them look better

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Underside view looking very curvy!

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The tailpipe has been sanded and painted. I decided not to make a tailpipe tube and instead have shaped and painted the inside too. The rearmost former has been painted red/orange and when dry will have a little yellow added!

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The silver will have some blue heat streaks added then the lot will be covered with clear varnish.

The last photo also shows the elevator linkage made from piano wire soldered into brass tube, crimped and drilled to take an M2 clevis. I made up the rudder connection with a standard horn and a ball joint. I had seen it done in another blog and it allows the snake exit to stay close to the fuselage alongside the fin.

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Still nobody in here though. Must go shopping to get some guys to fly this thing!

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Edited By Chris Barlow on 29/12/2015 01:49:27

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Thanks Matt. Had my covering iron up to 145 degrees and a craft heat gun on the go. Still got the nose cone to cover so will try even hotter for that!

Just installed a battery & switch and weighed it without RX, pilots and canopy. 831g (29.3 oz) if Google is correct. The CG is currently 8mm behind the plan CG of 61mm from LE so hopefully the pilots and canopy will make up the difference. I am hoping to keep the RX inside the open space of the airframe and not have to slide it up the battery tube!

Edited By Chris Barlow on 29/12/2015 17:14:45

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Covering looks very good indeed Chris.

I agree with Matt - I much prefer Oracover. It is more substantial and does not wrinkle as easily. It is also a lot more dense in colour.

I have my iron at 150 degrees.

Tip from Phil - print the cockpit detail onto glossy photo paper.

I did push my receiver up the tube (ooh er missus!) and have not had any problems with it so far. Only problem I have had is the blessed scale switch and a launch with no power, so don't use that method ie. switch mounted in the fuselage with a wire pushrod to the exterior.

If you want to have no switch showing - most people do, try the T9 Hobby Sport magnetic switch used by the F3F boys.

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Thanks Peter.

Went with oracover on your recommendation and it does feel tougher than solarfilm but at the moment has lots of scratches in it which I hope to polish out! Set my iron at 145 degrees to stay on the safe side but will try it hotter for the nose cone!

I have mounted the switch through the fuselage just above the wing and directly behind the jet intake which I hope will prevent it from being switched off during launch! I'm never keen on push/pull rods for switches as I try ti minimise points of failure either whilst flying or those niggling simple problems which prevent flying. I'll get a photo of the switch later.

Just a quick question. How have you secured the battery in the tube? I was thinking of a 1/4 sq balsa rod to the back of the battery, "T"''d onto a strip of lite ply screwed across the opening?

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Battery switch...

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Hopefully out of the way of errant launching fingers!

Quickly made up the aileron linkages. These will be covered in black heat shrink tubing once adjusted and tested.

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This afternoons task is to mark out and cut some decals. Started with the simple one, a tapered stripe from the nose to the registration gap with a small cutout for the jet intakes

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The rear stripe and fin flash are a bit more difficult so I covered the area in masking tape and drew on the lines, changed my mind a few times and drew some more!

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When I was reasonably happy I cut some paper templates to position and trial fit, then cut some yellow trim. The trim is back to front and will be applied to the other side although I must remember to make a handed copy for this side!

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Thanks Phil & Phil!

A different colour scheme is all well and good but I have struggled to find good reference photos for it! I had cut the ply fairing and it has been floating around on the bench for ages! Each time I saw it I disregarded it as a piece of scrap! Good job you reminded me! It's now been covered and glued on!

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The yellow flashes are now complete. I decided to re do the top of the jet intakes as it will show up the non slip tread plates better.

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Now I need to print off some decals and the cockpit instrument panel which means bringing it into the house for measuring and comparing photographs.

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This is a great build blog Chris well done, really interesting. I can sympathise with your thoughts and cogitations.

Your idea about the battery is a good one - I just shoved it in. Because there is little space it stayed put. I think I also shoved a small piece of foam behind it to keep it there. Mind you I also followed it with the Receiver also wrapped in a bit of foam I think - depends on the C of G - might have strapped a bit of lead to it also - such a long time ago I can't remember.

Latest forecast shows an Easterly slightly to the South for the 2nd so presumably that will be its maiden at the Orme? Anyone also attending?

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Posted by Peter Garsden on 31/12/2015 09:35:36:

Latest forecast shows an Easterly slightly to the South for the 2nd so presumably that will be its maiden at the Orme? Anyone also attending?

Good to meet up on the slope this afternoon Peter. I think we left just in time before the heavens opened up!

Maiden should be at the Orme weather dependant although the JP will be pilotless and possibly instrumantless if I can't get the printer working!

Just another quick question, is the CG at 61mm correct or have people moved it forwards/backwards?

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