Chris Barlow Posted December 17, 2015 Share Posted December 17, 2015 It might be a little late for the mass build but after seeing a couple of JP's flying at The Orme I have decided to add one to my glider hanger ready for 2016. There should be plenty of time to glue one together ready for the first PSSA meet in 2016 but now some joker decided on a get together at the start of January! No problem though as I find deadlines get jobs done quicker! So first a quick catch up on the build so far. Last Sunday evening after spraying the Tiger Moth with fuel proofer I tidied off the bench and started marking out and cutting formers and ribs. Not much done really but at least the shed is setup for building again. Monday evening saw the front box assembled. I've never done a build based around a battery box before so it was a new method for me and I was quite surprised how stiff it was. The fuselage sides were also cut and 3/4 triangle blued in. Unfortunately I didn't have 1" triangle in stock so that was ordered the next day. Quote Link to comment Share on other sites More sharing options...
Chris Barlow Posted December 17, 2015 Author Share Posted December 17, 2015 On Tuesday I started on the wings. The skins had already been cut and glued together so it was simply a case of sticking the ribs in. I didn't really trust the drawing for the position of the spars so elected to mark and cut them when the ribs were glued in position to ensure all the cuts lined up. I lined all the ribs up with a piece of 1/2 triangle as a temporary leading edge. When the wing was all cyano'd up I removed the temporary leading edge and glued in the false leading edge. This evening I put a little thought to the aileron torque rods. I wasn't too keen on the method detailed on the plan as I feel there are too many points of failure at each glue joint. I had ordered a pair of 14g torque rods but felt that the ribs at the trailing edge are quite thin to take the bearing tubes. I had been toying with the idea of fitting a servo in each wing so got a couple of 9g metal geared servos out to see if they'd fit inside the wing. When positioned tight up to the main spar there is just 1mm clearance between the servo and the top skin of the wing. The idea then is to glue some locating blocks to the spar and rib around the servo area, for the servo and wire through the wing and apply double sided tape to the top of the servo to secure it to the upper skin. This will mean that the servos are built into the wing but if there is a problem with them in the future I will cot a circular access hole in the underside of the wing to access the servos. The main task tonight was to get the top skin on the wing. I made the washout wedge from a strip of 1/8 balsa and pinned the wing to the bench, sandwiching the wedge between them. The double sided tape was applied to the servos and applied a line of aliphatic to all the top surfaces. The top sheets were pinned in place making sure the contacted all the ribs and all the way along each rib. The servo plugs were pulled through holes cut in the upper skins and slots were cut to allow the servo horns to poke through. The wing has been left on the bench looking like a blue porcupine whilst the glue fully dries. Hopefully tomorrow I will get the 1" triangle and can get on with the fuselage a bit more. Quote Link to comment Share on other sites More sharing options...
Matt Jones Posted December 17, 2015 Share Posted December 17, 2015 That's a rapid and tidy build there Chris They're great little flyers and we've had a lot of fun with them, good to see another one on the way. Subscribed! Edited to add: just a thought, you did sheet the wings separately so you can join with the required dihedral? Edited By Matt Jones on 17/12/2015 06:34:41 Quote Link to comment Share on other sites More sharing options...
Andy Meade Posted December 17, 2015 Share Posted December 17, 2015 Good luck with the build Chris, but don't feel obliged to get rush for the little get-together in January - it's just a general slope meet, not a PSSA one. I won't be bringing PSS stuff with me anyway Nice tidy work so far too, well done Quote Link to comment Share on other sites More sharing options...
Chris Barlow Posted December 18, 2015 Author Share Posted December 18, 2015 Matt, yes the wings are skinned separately. In the photo of the wing they were joined together by the spars which were cut before fitting the top sheet. Andy, It would be nice to be able to maiden it on the Orme as there is just so much lift there. I'm not too concerned if it's not ready but if not pushed I could still be building it in February! So not much done tonight, in fact actually nothing done on the JP at all due to a visit to Steve Webb models for their longest day. Treated my self to a foamie Wots Wot and a stick & tissue SE5a, which will probably be a Christmas present to me from my kids. I did however spend a bit of time assembling my new Slec building jig, lots of holes to drill! I've never really bothered with them before and usually spent ages setting up string lines down fuselages or screwing wooden blocks to the bench measured off a center line. Looking forward to trying out the new jig on the JP fuselage! Quote Link to comment Share on other sites More sharing options...
Chris Barlow Posted December 19, 2015 Author Share Posted December 19, 2015 Managed another couple of hours in the workshop last night and got the tail surfaces cut and glued up. I noticed from other build blogs that some have built theirs with rudder and some without. These were glued and pinned to the bench and left to dry whilst I got on with finishing the wing edges. I laminated up the wing tips first then cut the glue line holding the 2 wing halves together. All the wing edges were planed and sanded flush and the leading/trailing edges cut and fitted. This afternoon I intend to join the wing halves with the ply brace and get the fuselage together on the new Slec building jig. Edited By Chris Barlow on 19/12/2015 12:10:51 Quote Link to comment Share on other sites More sharing options...
Andy Meade Posted December 19, 2015 Share Posted December 19, 2015 Good steady progress Chris, keep at it! Quote Link to comment Share on other sites More sharing options...
Chris Barlow Posted December 20, 2015 Author Share Posted December 20, 2015 Thanks Andy. This afternoon I got the rest of the fuselage parts cut ready to try out my new building jig. It really is nice to use and quite strong. Makes a change from screwing blocks to the bench! Having read all the previous JP blogs I was a little concerned I didn't need all the heavy duty clamps to get the front of the fuselage to bend round but with a bit of checking it seems OK regardless. With the front glued up and looking OK I got the rear end of the fuse together at the same time. I did have to make up a couple of bands for the front angles as under pressure they were springing out at the top a little. As I used a combination of aliphatic and cyano I gave it just an hour to dry them could take it out of the jig and started on the decking. Made up a servo tray for rudder and elevator servos and fitted a couple of snakes... I had also done a little lightening of the rear formers... Last job this evening was blocking out the front of the fuselage. I've never had to do this before and will be the first to admit it looks like a pile of ugly, messy aliphatic sandwiches! Hope there are no voids under then when it comes to shaping! Quote Link to comment Share on other sites More sharing options...
Former Member Posted December 20, 2015 Share Posted December 20, 2015 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted December 20, 2015 Share Posted December 20, 2015 Fair bit of work for the razor plane there Chris...happy days John Quote Link to comment Share on other sites More sharing options...
Paul Marsh Posted December 20, 2015 Share Posted December 20, 2015 Done quite a bit since I saw it last night... Suppose watching Star Wars, when I could be building... Looks like the workshop will soon be knee deep in shavings. Edited By Paul Marsh on 20/12/2015 10:47:41 Quote Link to comment Share on other sites More sharing options...
Former Member Posted December 20, 2015 Share Posted December 20, 2015 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Chris Barlow Posted December 20, 2015 Author Share Posted December 20, 2015 I was thinking of just putting it on the lathe & turning it down! Quote Link to comment Share on other sites More sharing options...
Former Member Posted December 20, 2015 Share Posted December 20, 2015 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Chris Barlow Posted December 20, 2015 Author Share Posted December 20, 2015 It's all lovely until you plane away too far and a gap appears! Nothing done today yet as I've actually been out flying! Whooo! Quote Link to comment Share on other sites More sharing options...
Steve Houghton Posted December 21, 2015 Share Posted December 21, 2015 Chris, This brings back fond memories of the mass build. Your building speed is impressive - nearly as fast as Matt's! I've been really impressed by my JP's versatility over a wide range of wind speeds. The penetration in high winds is remarkable for its size and weight. I notice that you seem to have added an extra piece of sheet at the front of the tailplane. Is this going to key into a slot in the fuselage, or do you have some other cunning plan in mind? Did you manage to sheet the curved fuselage top in two pieces, or did you resort to planking, like many of us did? Quote Link to comment Share on other sites More sharing options...
Chris Barlow Posted December 22, 2015 Author Share Posted December 22, 2015 After seeing Peter Garsdens and a couple of others flying from the Orme at the last PSSA meeting I was so impressed I just had to build one! So smooth & scale like. Sorry but there's no cunning plan regarding the extra bit at the leading edge of the tail plane. I got carried away cutting and didn't notice I had not cut the step needed to blend into the fuselage so I cut that bit out separately and glued it on! The curved deck is from 2 pieces joined along the spine and again I didn't have too much trouble getting it to bend round although it is quite a tight curve around F5. This and pulling the nose around the front formers has me a little concerned as it hasn't been as difficult or needed as much force as the other blogs I've read. Either I've got something wrong or maybe I've got bendier wood, better technique or just lucky? Tonight I've had the doors to the workshop open and a couple of fans running as I've been planing and sanding the fuselage and wings/leading edges. A carrier bag full of shavings later and it looks like this. The top decking mentioned before was getting quite thin where it met F5 so I have laminated a couple of pieces of 1/16th over that area to prevent it from breaking with handling. I also installed the elevator and rudder snakes in the fuselage before sheeting the bottom. The rudder snake exits the top of the fuselage near the tail. The hole for this was cut with a brass tube sharpened with a countersink bot on the inside and pushed through at the approximate angle. The bottom of the fuselage has now been planed and shaped and a little bit of fettling around the tail pipe but I have yet to form the round inside of the pipe yet. Tomorrow I intend to laminate up the tip tanks and nose cone and hinge the control surfaces. Whilst the laminations are drying I'll join the wing halves and cut the dihedral brace in. Quote Link to comment Share on other sites More sharing options...
Steve Houghton Posted December 22, 2015 Share Posted December 22, 2015 Chris, It was good to meet you up on the Orme this year, and I look forward to seeing your JP joining the PSSA Squadron. Thanks for your replies. I lengthened the rudder slightly on mine, to bring the horn lower down towards the snake exit, but others seemed to manage without this. I made my tailpipe from two laminations of 1/32 ply, wetted and wrapped around a 1.5v D cell, which someone else suggested. It worked a treat. Great build - I'm enjoying re-living this! Quote Link to comment Share on other sites More sharing options...
Peter Garsden Posted December 22, 2015 Share Posted December 22, 2015 Chris, just seen this and am delighted you are joining the JP club. They are such brilliant fast flyers in most winds, and probably the most versatile of all my PSS models and the one which gets most air. It can fly on any slope not just the Orme as some others. You have done really well not to have to use big clamps on the nose as I had to do. I also have a SLEC jig, they are brilliant and I use mine on every build for one purpose even for lining up the wings and tailplane if not building the fuselage. What colour scheme are you going for. I have had some brilliant formation flying with Matt as we both have the same scheme. Would be nice to see a new scheme. Good idea to go for the servos in the wings. The only disadvantage is a bit extra weight in the tips. Shouldn't be a problem. Don't know if you have canopy yet, but the Vac Forms one is better than the Traplet own one. They Traplet ones tend to steam up badly in the sun. Also if you want to pay less than £30 for transfers go to Model Markings. Tim is really good. Hope to see it at New Year. Quote Link to comment Share on other sites More sharing options...
Paul Marsh Posted December 23, 2015 Share Posted December 23, 2015 The two torqe rods that Chris was going to use weighed as much as the servo itself. By adding another servo, deleting the rods actually saved weight: Original plan: One servo two torque rods This one: Two servos, no torque rods = better control and simplier arrangement. The extra weight at the wings is a old wife's tale... Quote Link to comment Share on other sites More sharing options...
Matt Jones Posted December 23, 2015 Share Posted December 23, 2015 Old wives tale 'eh? Maybe worth reading about the moment of inertia.... Having weight further outboard of the centreline slows roll acceleration and deceleration, in short it makes roll control feel less 'crisp'.It's a very real effect but granted in our models not a huge concern. Quote Link to comment Share on other sites More sharing options...
Chris Barlow Posted December 23, 2015 Author Share Posted December 23, 2015 I can see how weight out towards the wing tips will slow the roll rate and at the same time dampen any wing wobble hopefully enhancing a stable, scale like flight. The servos are also as close to the wing root as possible whilst still into the aileron enough to limit the twisting effect in flight. I wasn't keen on the composite torque rods on the plan as there are many points of potential failure at each glue joint but at the same time as Paul has said the decent torque rods I bought are quite heavy and only add to the overall weight. I could compromise and not fit the wing tanks... But it just wouldn't look the same without them! Quote Link to comment Share on other sites More sharing options...
Chris Barlow Posted December 23, 2015 Author Share Posted December 23, 2015 Peter I have the traplet canopy which I have rough cut to check the sanding shape of the fuselage. It looks OK but not as clear or transparent as it could be. I have built Nigel Hawes Tucano which I was flying at the last meeting and was thinking of a black colour scheme to match. I have found a photo of a black one and it looks quite nice. Quote Link to comment Share on other sites More sharing options...
Chris Barlow Posted December 23, 2015 Author Share Posted December 23, 2015 An early finish from work so after appeasing the wife for an hour or so doing Christmassy stuff I started shaping the tip tanks. First sanded to elevation profile on the cheapo Aldi sander/grinder... Then sanded to plan profile on the sander. With the fench set to an accurater 90 degrees it makes light work of stuff like this. After planing the corners and rough sanding they look like this... Also cut & shaped the ailerons and cut the rudder out of the fin assembly. Still got stuff drying in the workshop so decided to come in for a brew & see what the rest of the world is doing! Edited By Chris Barlow on 23/12/2015 21:43:13 Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted December 23, 2015 Share Posted December 23, 2015 Nice work Chris, I would imagine the tip tanks are easy to get out of sync John Quote Link to comment Share on other sites More sharing options...
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