Lindsay Todd Posted August 16, 2015 Author Share Posted August 16, 2015 Managed to get the servo installed with a bit of fiddling to set the height correctly with a couple of shims of 3mm light ply to make sure the output arm sits about 3mm up from the tail plane support which will make it roughly central once the tail is installed later. In the end I added a 6mm support between the longerons and then cut the tail support and once the servo was installed inset a couple of 6mm square pieces to make good again. sounds more complicated than it actually was . Back to the sheeting and got the lower central fuselage sides glued in place together with a section that follows the two longerons forward to F1. The gap between the lower longeron and the ply crutch is for cooling. The central sheeting was cut on a diagonal at the rear from the angle change after of the rear cockpit to the point were the tail extends at a continuous line back in line with the bottom edge of the fuselage. This is to allow for a scarf joint in the sheeting to again add strength at this joint Next job was to fix the tail snake outer in position at a couple of points down the rear fuselage before the remaining sheeting goes on. Final job was to cut and prepare the first of the tail side sheeting panels, again cut on the diagonal for strength, I also added a few scraps and glued to the inside edge of the already glued sheeting to add support to the shape and additional contact area. The sheeting was then wetted and pinned in place. I will let this dry then re wet and glue down so some of the stress will be removed and will seat a little easier. More soon. Linds Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted August 21, 2015 Author Share Posted August 21, 2015 Bit more work done basically finishing off the sheeting on the fuselage continuing down the fuselage running at an angle that allows the 2mm sheeting to conform to the angle changes aided by being wetted and pinned whilst the glue dry's. Once all the main sheeting is done the fuselage can be given a good sand round off all the edges Last job tonight was to add some 2mm sheet triangular shapes to the door line of the cockpits, these were wetted on the outside face to aid the curve and glued in place aligned to the edges of the cockpit cut out. Next job will be the forward battery hatch cover and the general cowl area. More soon Linds Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted August 21, 2015 Share Posted August 21, 2015 I think you've got another winner coming along here Lindsay, it's looking really good and has all of the ingredients to make it a good flyer, while having a distinctive appearance. You'll lose count of those who ask you "what's that then"! Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted August 23, 2015 Author Share Posted August 23, 2015 Thanks Colin, yes enjoying this one so far, Bit more done on Saturday starting with the top cowl hatch. This is quite straightforward consisting of three formers that align onto two 3mm sheet strips and a 6mm square top longeron. 0.5mm ply is then wrapped around the surface with a 2mm overlap all round. First problem was that I had drawn the front two formers 6mm to narrow, dope, so this was quickly amended with some balsa glued to the perimeter and sanded back to the correct shape. These formers sit onto two 3mm balsa strips that sit on top of the top longeron on the fuselage and flush with the sides making them approximately 9mm wide. The formers sit up against the inside face of F1 and F2 and the third as mid position. To stop the hatch getting glued to the fuselage I applied some clear film to the mating faces on the fuselage and then glued all the bits in place and left to dry When dry the hatch frame can be removed Next job was to make a card template for the ply wrap. I chose to go from the centre line of the top longeron and round one side, then repeat for the other but this was due to the size of 0.5mm ply I had available, it would be jus as easy to do in one piece. The aim is to have about a 2mm overlap of the frame all round. Whilst the hatch was drying I also glued together what will be the nose of the cowl made up from laminates of soft 6mm balsa - ok I used parts cut by Slec which has made this easier but basically get stacked and glued together The reduced length on the top two simply reduces the amount of carving and sanding to shape. More soon. Linds Quote Link to comment Share on other sites More sharing options...
Former Member Posted August 23, 2015 Share Posted August 23, 2015 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted August 24, 2015 Author Share Posted August 24, 2015 Thanks PV nice that this one is a bit of a civil military crossover, something for everyone Finally got the ply wrap on the cowl done, just a bit of filler to the centre joint, sand and final trim to fit required The lower sides of the cowl are again from 0.5mm ply and have a slight curve to the sides creating a natural air gap for cooling so the ply needs to be slightly oversize and glued on three faces aligned with the top hatch seem line front of F1 and the lower fuselage edge. I cut and sized a card template for this and test fit. Note this is measured before the underside of the cowl is done although will not be fitted till later as I want to get a paint finish inside the visible areas but easier to measure and create the template now. Before the underside of the cowl gets sheeted some triangular stock was added to the rear of the nose undercarriage plate for extra strength and just sanded flush. The black line marks the end position of the cowl sides which angle slightly forwards . next job, sheet the underside of the cowl and shape the nose block. Linds Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted August 28, 2015 Author Share Posted August 28, 2015 Managed to get a bit more done starting with the 6mm cross grain sheeting to the underside of the nose and the soft block tail cone as well. Then had some fun carving the cowl nose cone to shape with a razor plane. This was also opened up on the inside with a dremel rotary sander and then glued onto the front of F1 Time now for some filler and a good sand before moving onto the tail plane more soon Linds Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted August 28, 2015 Share Posted August 28, 2015 Ahhh it`s getting there now and a nice block of wood up front . Steve Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted August 28, 2015 Author Share Posted August 28, 2015 nothing more fun than standing in a pile of shavings Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted August 31, 2015 Author Share Posted August 31, 2015 Time to make a tail plane, bit more complicated due to the linkage for the H tail twin fins but having been chewing over a few option I have settled on what I think is a pretty simple solution and provides a choice for servo or torque rod connection. The tail plane build starts with strips of 6mm balsa arranged and glued together over the plan. A 6mm spruce spar is also let in just behind the leading edge spanning the centre section to add strength. when dry a 1.5mm balsa sheet is glued to the underside with a centre access slot for connection to the snake Next we have to let in a control rod, I used a conventional snake and so trimmed a slot just forward of the trailing edge and glued the outer lengths of the snake in place. This is deliberately cut short of centre and ends to allow some movement of the in at the connection points The inner linkage is a conventional inner with wire outer lengths and z bends to connect to the rudders. The centre linkage is simply a screw through the inner tube, this in turn is now connected to a torque rod assembly or through the output arm of a servo. As the torque system is a bit lighter I have decided to go with this option which is basically a 2mm wire with to 90degree opposed bends running in a brass tube mounted onto a ply and balsa frame that fixes directly onto the servo mount. the connection to the snake is via a clevice with tag arm removed leaving just the hole and the other arm will pass through the fuselage side for a snake connection Just needs a bit of measuring then the top 1.5mm sheeting can be added, I will trim a connection access when dry which will later have a cover plate for maintenance. hope that makes sense, will become clearer as things progress I hope. Linds Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted August 31, 2015 Share Posted August 31, 2015 Hi Linds, I have made a similar connection to the one above, to link two Ailerons to one servo but rather than putting a screw through the Centre of the snake i cut the inner snake and re-joined with a threaded rod and used a standard connector to connect to my servo arm . And this over the Rod . I will take a picture of it , if it helps . Steve Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted August 31, 2015 Author Share Posted August 31, 2015 Hi Stephen, yes familiar with the linkage and was a consideration but the key issue was to keep the linkage no deeper than 6mm to keep it within the tail plane depth and avoid an additional compromise. The screw of course is trimmed to size and can get this complete system to just under 5mm. I am sure people have and devise alternative and better systems but it's the best I have come up with for now, perhaps compromised to some extent by the bits and pieces I have around me. Thanks for the input always welcome. Linds Edited By Lindsay Todd on 31/08/2015 21:25:37 Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted September 3, 2015 Author Share Posted September 3, 2015 Bit more of an update with the sheeting on the tail complete the access space was opened up and the tail rested on the fuselage for a test fit and check the rudder centre linkage works freely. This will later have a thin ply hatch but for now all is good and time to make the elevators The elevators are made from 6mm balsa cut into strip width of 12mm and glued together over the plan. addition wedges are added to the inside joint to allow for the wire joiner and 1mm ply laminates will be glued top and bottom for added strength. Next job a bit of sanding to shape the leading and trailing edges, then make a start on the fins and rudders More soon. Linds Quote Link to comment Share on other sites More sharing options...
Former Member Posted September 5, 2015 Share Posted September 5, 2015 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted September 5, 2015 Share Posted September 5, 2015 Percy, I like you're idea , it would allow each snake to move normally , I shall keep that one in mind for further use . Steve Just goes to show their is more than one way to skin a cat . Edited By Stephen Jones on 05/09/2015 20:17:00 Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted September 5, 2015 Author Share Posted September 5, 2015 Yep like that and duly noted for future use. Have made a start on the fins, well finished actually and will gets some pics up later but was down at my mates workshop today and jigged the tail and fins onto the fuselage just to take a look. The fuselage has now received a coated of acrylic resin which acts as a sanding sealer so now ready to start covering the fuselage very soon. Rudders next then to make a start on the wing. Linds Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted September 5, 2015 Author Share Posted September 5, 2015 Fins are made up from 6mm square and some 6mm sheet. The most awkward bit being the one that actually locates the fins onto the tail. I had these awkward bits laser cut but just need a bit of care. Build over the plan using 6mm square balsa front and back with wide strip cut to length to bridge. Once dry the part can be sanded to shape and of course a duplicate made. I also added the ply facings to the elevators and sanded to shape, these add strength to the joiner position and fixing of the control horn. Linds Edited By Lindsay Todd on 05/09/2015 21:51:26 Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted September 11, 2015 Author Share Posted September 11, 2015 Well cracked on and now got both rudders built up, similar to the fin all from 6mm balsa in various widths built up over the plan basically leading edges 12mm wide, trailing edge 6x6 square, 12mm again at the top and bottom, a 6x6 brace and the critical one a 12mm wide brace tat will carry the rudder horn and some 3mm wide diagonal braces. The awkward bit is to cut out the horns, I had these laser cut from 1mm ply but aluminium, epoxy plate, paxolin are all just as good. these locate in a slot that needs to be cut aligned with the wide hole in the fin section. so mark carefully before cutting. I will glue these in place later when I finally glue the tail parts to the fuselage and connect up the linkages so I can set the geometry accurately doing it now will cause a few headaches later but a dry fit looks like this Just remember to make up a left and right hand side, the horns go on the outside faces. next job some covering on the fuselage and make a start on the centre section of he wing. More soon. Linds Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted September 11, 2015 Author Share Posted September 11, 2015 As planned I have the fuselage now glassed and drying awaiting a sand tomorrow so this evening I made a start on the centre section of the main wing. This carries the main undercarriage and spars so the first job is to make up the undercarriage plates that are made from laminates of 3mm marine grade ply, two long laminates that bridge the ribs and 3 smaller laminates that are a location for the leg anti pivot torsion bend on the leg. The spars are also from 3mm marine ply. I started with the rear lower spar, this is made from 6mm spruce for strength as the undercarriage blocks will be glued directly to it. taped down on the plan the two long u/c mounts can be glued together and then glued to the back of the rear spare aligned with the first rib position ensuring the hole is on the centre side of the wing Next the forward spar from medium 6mm balsa can be positioned using ribs to ensure correct location and pin in place over the plan and again cut to length. The 3mm spar braces for the forward spar can be glued to the rear of the balsa spar aligned with the rib positions and left to dry. The first two inner ribs can then be glued into position over the spars and undercarriage mounts. When dry add all the remaining vertical positioned ribs leaving the end ribs each side which will be set at an angle to align with the outer panels later. I decided to leave fitment of the rear spar braces till later. Also make sure the gap between the inner first and second ribs matches the width of the small undercarriage laminates to avoid trimming them down a bit later as I now have too! Once dry I will add the top balsa forward spar and spar braces and trim down the triple laminates for the undercarriage blocks and glue those in place. so job for tomorrow I think. The camera angle makes it looks like the ribs are short on the plan. I like building wings, lots of evidence for not much time spent. Linds Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted September 13, 2015 Author Share Posted September 13, 2015 Bit more work done starting with making a template jig off the plan to set the angle of the outer ribs on the centre section to the dihedral angle. This important as they need to align with the first ribs on the outer panels when I come to glue the three wing sections together. The next job was to cut the trailing edge section to length and then cut out the mid section. This is a commercial 38x9mm trailing edge section. Cut the centre out with care as I will use this later. Next was to fit the leading edge, this is simply 6mm balsa cut to width and length and glued onto the front of the ribs with a couple of triangular triangle pieces on the inside face for strength. Once dry I added a 3mm light ply brace to the forward face of the front spars between the two centre ribs and full chord depth. this both adds strength and will also be a support for the wing dowel. With that done I started the top sheeting in 1.5mm balsa working from the tailing edge forward leaving about 25mm to the leading edge so that I can deal with the dowel and support plate next. We need to add a 3mm light ply support plate into the leading edge and so a slot needs to be accurately cut away so that the plate can be glued in place. My technique was to position the support plate on the fuselage aligned with a dowel and then taped into position just at the edges leaving sufficient space for glue to be applied. I then remove the dowel use the plate held by the tape to measure the position of the plate on the leading edge. Trim away as required then add some glue to the slot and then position the wing back in position and weigh down so that it sits snuggly in position having first checked all is square of course. when dry the slithers of tape can be removed and some thin cyno added to enhance the glue joint. This will be further improved when we add the dowel and the final section of sheeting. More soon, when after it dries. Linds Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted September 13, 2015 Share Posted September 13, 2015 Fascinating detail Lindsay, it is a great build. Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted September 13, 2015 Author Share Posted September 13, 2015 Thanks Colin, really enjoying this design & build Quote Link to comment Share on other sites More sharing options...
Former Member Posted September 13, 2015 Share Posted September 13, 2015 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted September 14, 2015 Share Posted September 14, 2015 Still watching , I must crack on with my drawings too many eggs in one basket i am afraid . Steve Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted September 17, 2015 Author Share Posted September 17, 2015 Thanks guy's I sometimes wonder if anyone reads this so many thanks. Anyway a bit more done since last time starting with the fitting of the dowel in the leading edge and secured against the front face of the spar with an additional ply plate with a 6mm hole drilled giving a very secure fixing. The eagle eyed will notice a slot just aft of the spar in the ribs, this is not used it was simply the fact that all the ribs are the same size so I made them all the same and will adjust this on the final plan. next job involved some wire bending of 4mm piano wire for the main undercarriage and then a quick test fit to make sure all fits ok. I also trimmed away a square in the top sheeting centre section for future access to extension cables etc. Time for some 1.5mm sheeting to the underside. I was careful to mark the position of the undercarriage carefully on the sheeting and then trimmed away a slot when dry. I will later trim away the location for the securing saddle clamps for the wire also. Next job was out with the credit card and commit to the purchase of a wire bender. Now this is not critical for this model but I had a unit years ago and is so useful. The end result is I can now make coil spring nose legs such as this. Ok not a scale leg but fine for a sport scale design. A rummage through the bits boxes found a nose wheel of the correct size and a quick test fit to the fuselage The nose leg slots into the nylon block on the forward undercarriage plate and a collet below and steering arm above are just required to complete Could not resist the first opportunity to sit the model for the first time on her legs Next job will be to fit the wing bolts and then make a start on the outer wing panels. Possibly ready for Ashbourne ? better get a move on. More soon. Linds Quote Link to comment Share on other sites More sharing options...
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