Lindsay Todd Posted June 3, 2018 Share Posted June 3, 2018 I have quite deliberately held back on the build blog with the series of design based articles going in the magazine but as the plan will be featured this month its time to back track a little through my build notes and add some further details of the construction for those interested. I'll try and get this done asap. Its been a refreshing project in many ways and the result is a great performing sport model that is pretty straight forward to build. Linds Quote Link to comment Share on other sites More sharing options...
Timo Starkloff Posted June 3, 2018 Share Posted June 3, 2018 Looking good Quote Link to comment Share on other sites More sharing options...
Former Member Posted June 3, 2018 Share Posted June 3, 2018 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted June 4, 2018 Author Share Posted June 4, 2018 So a backtrack build blog, so were to start well as most people probably know I start these days by getting a set of parts laser cut by Slec (they are used to my drawings by now) and with a build for a magazine when time is a pressure then it does make life a little easier. All the formers are made from either 3mm light ply or marine ply for parts such as the 6mm motor bulkhead and undercarriage block. Wing spars are made from 3mm marine ply and ribs from 3mm balsa. With this design I have deliberately were possible used as many stock commercial materials and sizes as possible so they should be relatively easy to obtain. As my article hopefully showed and was produced as the model was being built, put the effort in up front and the build can be straightforward enough, laser cut parts are only as good as your drawings so double check the sizes. I had made a basic error with one mid rear former and needed to cut a modified part during the build, mistakes happen but at least it showed the process warts and all. The build started by cutting two fuselage sides from 6mm medium density balsa and two wing doublers from 3mm medium density balsa (you could use light ply for additional strength but I was happy to go with balsa) The laminate gets glued onto each fuselage side aligned with the wing cut out. just remember to make a mirror pair! Whilst that was drying I sited the engine onto the mount and aligned the mount to the 6mm motor mount bulkhead and marked the position of the holes for the mount, throttle arm linkage and a centre clearance hole for the fuel lines. The little slot in the former is not required for I/c engines but the former was designed around originally using electric power so if the is your route then its a useful addition to feed cables through and add some additional cooling airflow. The motor mount was also fitted with captive nuts to secure the motor simply as it is easier at this stage due to limited access later. NB the balsa additions to the base to increase the depth, again a result of choosing to go IC and the mount had to be moved further back so the former needed extending. As the bulkhead gets fully support this is not a problem but I should have really replaced the former with a full marine ply item if I am honest. Back to the fuselage construction and with the doublers dry each fuselage side can be pinned to the plan and then the top and bottom rear longerons which are made from medium to hard density 6mm square balsa. These can be cut to size and glued in place to the rebates on the fuselage sides. Take care with accuracy as the top longeron assists in setting the rear incidence on the tail plane. A 6mm balsa plate is glued to the longerons and forms the incidence line for the tail plane so cut and set with care. Vertical braces again from 6mm medium balsa can be cut and glued in position down the rear fuselage sides. When complete repeat the process for the second fuselage side. (I used the first completed side as a template for the second or you could just draw around it to replicate. Next job is to fit the centre region formers that include the former that sits at the front of the wing that will carry the wing dowels, a ply plate that is effectively a servo tray and the mid wing seat former. These all have tags and slots so the formers key together and are then aligned to the step at the front of the wing cut out and the top edge of the doubler. Just make sure all is square and glue in place to the first fuselage side. NB the servo tray element again is shown here as a solid plate with a circular hole. This locates to the front battery or tank bay support. I later trimmed away a larger hole to site the throttle servo lower down in the fuselage. This may not be necessary depending on the motor you intend to use but worth thinking about as would be obviously easier to cut first and then glue in place. I used a drill and tapered razor saw blade but without such a tool it would be tricky so again plan ahead if you can. With the first two formers in place we then need to set the position of the motor mount. The plan shows the position based on the motor I used which was an ASP52 Four stroke however if you measure the distance from the motor mount to the prop boss on the motor and add a couple of mmm you can re set this former correctly to the motor you are using and it will not really affect anything other than trimming the fuel tank / battery support plat to a new size before gluing into place. The cut outs on the sides of the tank or battery plate are for loop and hook straps to pass through and around. more soon. Linds Edited By Lindsay Todd on 04/06/2018 00:25:04 Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted June 5, 2018 Author Share Posted June 5, 2018 Motor bulkhead former F1 and F2 showing the doubler added in front of F2 at the dowel position and triangular reinforcements to the sides. 6mm square balsa has also been added to the lower fuselage edge The fuselage sides can now be glued together, at the rear two triangular wedges of 6mm balsa brings the sides together, the top forms the tail plane seat. Clamp till dry. I use a range of clamps and elastic bands to keep everything together. NB ormer F7 on the bench, I added this once the glue was dry as it just seemed to be easier to locate its position correctly. Time to add the 6mm square balsa stringers around the upper sections of the formers, these provide support and gluing area for the outer sheeting NB the position of the 6mm stringer that sits at that is glued onto the top of the 6mm sheet fuselage sides. these are inset to allow the top sheeting to match the outer edge giving a good glue joint. The rear top section of the fuselage is made up of a central stringer and then an additional 6mm strip cut to width, a razor plane was then used to shape the strip to match the former profiles ready for sheeting The section just forward of the cockpit has a series of 6mm stringers to create support and gluing area for the top sheeting. NB the 6mm inset strip does not extend into the area that will become the fuel tank / battery hatch Final jobs before sheeting was to add the 6mm marine ply u/c plate as it offers a bit of protection and also add the triangular strip section around the formers and u/c plate whilst we have access more soon. Linds Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted June 6, 2018 Author Share Posted June 6, 2018 So time to start some sheeting using 3mm soft balsa trim roughly to shape, I then moisten the outer surface to aid the bend and then glue in place with aliphatic glue and pin in place to sides, formers and stringers. When dry repeat for the other side The sheeting can also be added to the front including around the cockpit using the same technique using pins and pegs to secure till dry and then repeat for the other side. Make the cockpit slightly oversize so you can trim back more accurately to shape later. also a good chance to add the 6mm balsa sheeting to the underside front fuselage from U/C plate forward leave till dry and trim and sand to shape. more soon. linds Quote Link to comment Share on other sites More sharing options...
Timo Starkloff Posted June 6, 2018 Share Posted June 6, 2018 That looks strong but light. And easy to build What’s the size and weight of the finished model and which airfoil do you use? Edited By Timo Starkloff on 06/06/2018 19:14:00 Edited By Timo Starkloff on 06/06/2018 19:14:20 Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted August 19, 2018 Author Share Posted August 19, 2018 Had not realised that the build overview had already been released on this site so will close this off as no point in repeating. Linds https://www.modelflying.co.uk/news/article/building-renaissance/26382 Edited By Lindsay Todd on 19/08/2018 22:51:29 Quote Link to comment Share on other sites More sharing options...
david field 1 Posted September 9, 2018 Share Posted September 9, 2018 What is a good average size of a tail plane to wing proportion? I am rebuilding a 1980 ish design low winger pattern ship, but upgrading to electric, so need to build a ' built up tail plane and fin/ rudder'. David Field ex wrcfs. Quote Link to comment Share on other sites More sharing options...
Nick Brotherton Posted October 16, 2018 Share Posted October 16, 2018 My club mate is building one of these. But the lower part of the fuzz is scolloped? Any reason why when it could have been one piece as here? Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted October 24, 2018 Author Share Posted October 24, 2018 Hi Dave, re tailplane area, 18-20% of the main wing area is usually a pretty safe bet. Linds Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted October 24, 2018 Author Share Posted October 24, 2018 Hi Nick, sorry not sure I understand the question about the fuzz being scalloped, can you elaborate a bit? Quote Link to comment Share on other sites More sharing options...
Nick Brotherton Posted October 24, 2018 Share Posted October 24, 2018 The lower part of the fuselage sides is cut into 2 parts and the edges are in the shape of a wavy line but forms the correct shape when joined together. It's the part of the fuzz just above the wing that's shown in your last photo where it says "Leave till dry and sand and trim to shape". If you don't know about it then it must be a manufacturing fault? Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted October 25, 2018 Author Share Posted October 25, 2018 Hi Nick, sorry still a bit confused as he last photo relates to gluing the u/c plate and underside of nose section that spans across the fuselage and then sanded and trimmed to shape, I can't see a 'wavy line' anywhere. Are you referring to the internal fuselage tray that forms the battery bay and servo tray that has a jigsaw type joint, if so that could be a single piece, its just the way it was designed for the cnc parts and not critical in any way. Linds Quote Link to comment Share on other sites More sharing options...
Nigel R Posted October 25, 2018 Share Posted October 25, 2018 I wonder if nick means the wing saddle? Quote Link to comment Share on other sites More sharing options...
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