Gary Manuel Posted April 6, 2014 Share Posted April 6, 2014 Anyone interested in a build log for a traplet Farmhand 90? It's been done before on these forums, but I've made a few minor changes and I always think it's a good idea to see how different people tackle things. I've been posting it on my local club forums and have just joined RCME. I don't mind re-posting what I've done to date, then going live with the finish if it will be of interest to anyone. Quote Link to comment Share on other sites More sharing options...
cymaz Posted April 6, 2014 Share Posted April 6, 2014 Oh yes please always like to watch a build, I always learn a thing or two. Quote Link to comment Share on other sites More sharing options...
Andy Green Posted April 6, 2014 Share Posted April 6, 2014 Always interested. I agree its good to see how problems are tackled by builders, thats what makes the mass builds so interesting. I built the wings for someone a few months back, found the plans and video lacking in some important areas. Andy Quote Link to comment Share on other sites More sharing options...
Gary Manuel Posted April 6, 2014 Author Share Posted April 6, 2014 OK here goes. I'll do a brief introduction first: The Farmhand 90 is a 90 inch wingspan approximation of a piper pawnee crop duster. It's made from a woodpart kit supplied by Traplet publications along with a DVD, which shows most (not all) of the important steps of building and flying the model. The wood pack is litterally that - 13 (I think) sheets of laser cut ply / balsa. There are no other materials supplied, including a fair amount of stock balsa / ply, so this is left to the builder. It does add a fair bit to the overall cost of the model. This is a video created by the designer, which is s good introduction to the model I think. Quote Link to comment Share on other sites More sharing options...
Gary Manuel Posted April 6, 2014 Author Share Posted April 6, 2014 I'm having a spot of bother displaying the above video (can anyone else see it?) and adding photos. I'll be back when I've sorted my problem. Quote Link to comment Share on other sites More sharing options...
iqon Posted April 6, 2014 Share Posted April 6, 2014 It`s there for me looking forward to your build... Quote Link to comment Share on other sites More sharing options...
Gary Manuel Posted April 6, 2014 Author Share Posted April 6, 2014 Sorted. It was Internet Explorer compatibility issues. Here we go then: The first job was to separate the parts form the wood pack sheets and run a vacuum cleaner hose over them to remove the soot from the CNC laser cutter. Starting with the two fuselage sides: They are made up from two interlocking parts, which were fitted together, masking taped and glued using medium cyano. 6mm square stringers were then added to the top and bottom of the fuselage halves, ensuring that I was making a left and a right hand half. Offcut of light ply were then cyano'd on the INSIDE of the fuselage sides for the servo screws. Quote Link to comment Share on other sites More sharing options...
Gary Manuel Posted April 6, 2014 Author Share Posted April 6, 2014 Several formers need to be laminated together for added strength. For example, Former F2 is laminated to former F2A. The small rectangular slot is for a matching tongue in the front of the removable wing. The large square hole is for the tank / engine box assembly - more on this later. Quote Link to comment Share on other sites More sharing options...
Gary Manuel Posted April 6, 2014 Author Share Posted April 6, 2014 The fuselage is then built up from the various pre-cut parts, rather like a 3D jig-saw. The parts are "tacked" in place with thin cyano to hold things in place as you go: Quote Link to comment Share on other sites More sharing options...
Gary Manuel Posted April 6, 2014 Author Share Posted April 6, 2014 Very quickly, you finsh up with something which resembles an aeroplane fuselage. This process is really very quick. I think it only took an hour or so to assemble these parts. The assemby instructions and the DVD are very clear on showing how this goes together, so I'll not dwell on it. Quote Link to comment Share on other sites More sharing options...
Gary Manuel Posted April 6, 2014 Author Share Posted April 6, 2014 And from a slightly different angle: Quote Link to comment Share on other sites More sharing options...
Gary Manuel Posted April 6, 2014 Author Share Posted April 6, 2014 More laminating. Quote Link to comment Share on other sites More sharing options...
Gary Manuel Posted April 6, 2014 Author Share Posted April 6, 2014 To give some idea of scale, that's a 300mm / 12 inch steel rule and the tape measure is to the rear of the fuselage (excluding rudder and cowl). Quote Link to comment Share on other sites More sharing options...
Gary Manuel Posted April 6, 2014 Author Share Posted April 6, 2014 Tank / engine box assembled - Note that the firewall at the front is one parts that were laminated earlier. Quote Link to comment Share on other sites More sharing options...
Gary Manuel Posted April 6, 2014 Author Share Posted April 6, 2014 I decided to drill / peg the firewall with cocktail sticks for added strength. I also epoxy'd triangular strip inside the 4 front faces of the box later. I don't think it needed this, but better safe than sorry. Quote Link to comment Share on other sites More sharing options...
Gary Manuel Posted April 6, 2014 Author Share Posted April 6, 2014 A narrow bead of white glue (aliphatic resin in my case) into all joints pushed / smooth in with a cotton bud. This is the basic process of fuselage construction recommended by the designer - tack with cyano, then fillet with white glue later. It seems to work Quote Link to comment Share on other sites More sharing options...
Gary Manuel Posted April 6, 2014 Author Share Posted April 6, 2014 And arround the tank / engine box. Note that this becomes an intergral part of the fuselage and makes for a really strong front end. Quote Link to comment Share on other sites More sharing options...
Gary Manuel Posted April 6, 2014 Author Share Posted April 6, 2014 A bit of strengthening added to guard against the engine pulling the entire tank / engine box out of the fuselage. This is not in the designers guidelines but I thought it was a good idea. Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted April 6, 2014 Share Posted April 6, 2014 Looks a nice kit Gary Not a model I have seen, whats impression of quality so far ? Quote Link to comment Share on other sites More sharing options...
Kevin Fairgrieve Posted April 6, 2014 Share Posted April 6, 2014 Glad to see you did not have the same issue`s that I had. My Farmhand build. It is finished ready for covering. Kev Edited By Kevin Fairgrieve on 06/04/2014 17:35:14 Quote Link to comment Share on other sites More sharing options...
Gary Manuel Posted April 6, 2014 Author Share Posted April 6, 2014 Posted by Kevin Fairgrieve on 06/04/2014 17:25:58: Glad to see you did not have the same issue`s that I had. My Farmhand build. It is finished ready for covering. Kev Edited By Kevin Fairgrieve on 06/04/2014 17:35:14 Hi Kevin, I read your blog with interest before I started mine. Gave me a few tips for what to look out for. I assume the issues you are talking about are the inaccurate laser cut parts. No mine were all pretty good. I felt for you when you got to the bit where the servo holes were in the wrong ribs The positive side of making the mistake and publishing it is that it helps others avoid similar problems. I made sure that I cut some small squares in the lower surface before I skinned the top (see later in my build log). You can take some credit for that Quote Link to comment Share on other sites More sharing options...
Gary Manuel Posted April 6, 2014 Author Share Posted April 6, 2014 Posted by john stones 1 on 06/04/2014 17:17:34: Looks a nice kit Gary Not a model I have seen, whats impression of quality so far ? Hi John, Not the prettiest of models, but it's certainly got character and I'm sure it will be a real work horse. As a designer myself (not models), I can appreciate some of the excellent design features of this model. I'm very impressed by how well it goes together and the speed that the fuselage can be built. The only quality issue I have noticed is that some of the "denser" sheets of ply were not cut cleanly all the way through. It is as if the CNC laser power needed turning up a bit. It resulted in the finished face being slightly tapered, and was tricky to break free from the cut sheet. Nothing a sharp knife and bit of sandpaper couldn't sort though. Quote Link to comment Share on other sites More sharing options...
Gary Manuel Posted April 6, 2014 Author Share Posted April 6, 2014 Part DE is a triangle of lite ply reinforcement. The photo is a view from the underside at the front and will soon be covered by the undercarriage plate. Note the 6mm step between part DE and the edge above it and also the step between the former at the left hand side. This is intentional in order to give the undercarriage plate plenty of interlocking surface area for achieving a good glued joint. More on this later. The part on the left is laminated former F2 / F2A as shown earlier. Quote Link to comment Share on other sites More sharing options...
Gary Manuel Posted April 6, 2014 Author Share Posted April 6, 2014 This is the undercarriage plate as offered up to the hole in the fuselage. Note the top-hat shape. This is made up if 4 pieces of 3mm lite ply laminated together. 2 smaller than the other, with a 3mm overhang all round. This allows it to sit in the hole, and be bonded on 2 faces to former F2A (with the slot for the wing tongue) and the triangular reinforcements DE. All in all, a well thought out front end. Note that the undercarriage will screw into the plate using self tappers, rather than the usual captive nut / bolt arrangement. Quote Link to comment Share on other sites More sharing options...
Gary Manuel Posted April 6, 2014 Author Share Posted April 6, 2014 Trial fit of the undercarriage plate Quote Link to comment Share on other sites More sharing options...
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