John Hickson Posted December 5, 2012 Share Posted December 5, 2012 Stirling work, I'm looking forward to the rest of this build! Quote Link to comment Share on other sites More sharing options...
iawnski Posted December 5, 2012 Share Posted December 5, 2012 awesome phil Quote Link to comment Share on other sites More sharing options...
Matt Jones Posted December 5, 2012 Share Posted December 5, 2012 How are you going to hinge the flaps and ailerons? Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted December 5, 2012 Author Share Posted December 5, 2012 Matt - the ailerons are being fitted with half round balsa Leading Edges and they will be conventionally hinged with the Robart 'knuckle' type hinge mounted on the centreline, 4 per panel as the ailerons are huge. The flaps, just like your Lightning, will be left square, butt-jointed to the wing and a bottom hinge will be employed for free movement down with a zero gap look on the top surface when the flap is raised. This is to help me cover my 'non-scale' tracks with the flaps, as they should really be spilt and elongate away from the wing when lowered on an arc. Far too complex for our PSS models when there are no wheels to lower to protect them on landing! Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted December 27, 2012 Author Share Posted December 27, 2012 I've managed to get a bit of work done this week in between family commitments and the endless turkey sandwiches... with the flying surfaces 'removed' from the foam wings just prior to Christmas I've been focussing on getting them lined and sanded to profile before I can put them to one side for covering. Having cut them away from the main foam wing section further cuts were made on the flying surfaces to allow for L/E and end plate stock, balsa and light ply respectively. The ailerons received a 21mm thick balsa L/E, this to allow for a semi circular section at the required radius. The flaps were to be bottom hinged, hence they only needed 1/4" balsa sheet. Once dressed up the end plates were made and fitted in light ply, the required sections were drawn on for reference and then the sanding could begin. Shaping the aileron proved a little tricky as the L/E rad reduced significantly from root to tip and even my longest sanding block was not long enough to span the aileron with a single stroke. The light ply end caps make for a robust 'ding proof' edge and corner for these large flying surfaces. The ailerons will be conventionally hinged on the centreline, the flaps are intended to sit flush to the wing with zero gap when not in use, and Im planning to use step aside hinges to allow the panels to droop as flaps when required. Heres the step aside hinges Im using, 3 per panel. With the flying surfaces all dressed and finished we can focus again on the main wing panels. Quote Link to comment Share on other sites More sharing options...
Matt Jones Posted December 28, 2012 Share Posted December 28, 2012 Those sure are big surfaces! Those hinges are really nice, I've used them before and they work really well. Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted January 1, 2013 Author Share Posted January 1, 2013 Got a bit more work done on the wing outer panels today, not a bad way to see in the new year I suppose With the ailerons and flaps all finished awaiting their hinges, I needed to work up the false T/E on the wing panels. Before that could be fitted, I needed to embed 4 x medium balsa blocks in each panel to take the robart knuckle hinges on the ailerons. The cavities were cut out along the centreline and the 4 blocks were dropped in with epoxy ensuring they were flush with the foam. With the 4 blocks secure, a hard 1/4" balsa sub T/E was cut from 1/4 sheet, one for each half. This was glued down along the T/E ensuring good contact along the span - hard balsa has been selected here as this will effectively act as a spar for the outer panels. The T/E were taped and left to dry on a flat board as shown. All that remains now is for a little sanding to profile before the hinge C/L can be found and the hinge locations can be marked up and cut. Quote Link to comment Share on other sites More sharing options...
the unmagnificent man Posted January 1, 2013 Share Posted January 1, 2013 Wow Phil what a fantastic blog. I think that the work you did on those naccelles and the gun is second to none, they look absolutely real and yet all built with a minimum weight goal. Its good to see that some people (especially in our hobby) are still able to create what they need from things other than a kit. I look forward to seeing what comes next. Well done. UMM Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted January 5, 2013 Author Share Posted January 5, 2013 Got a bit more work done this evening on the flaps - in particular, the mount points for the offset hinges I'm using for them as I wanted to ensure an accurate and robust hinge mount with this arrangement. I was a little unsure as to the exact positioning and orientation of these hinges, as no instructions came with them as purchased and I've not used them on a model before, so during the week I'd made up a simple 2D test piece to play with which led me to a satisfactory orientation and axial location relative to the wing/flap split line. Once I was happy how and where they were to be located, the next job was to make up the 12 hinge mounts, using hard balsa. The close up (below) shows how the hinge will be mounted and operates in the perpendicular grooves. The balsa block mount on the left will be fitted into the wing, the one on the right will be fitted into the flap, and that was tonights task. So having marked out the required position of each hinge, 3 per panel, veneer and foam was removed to accept the blocks... ...which were potted with 5 minute epoxy flush to the veneer surface, shown here finished bar a final sanding. A dry fit of the hinge proved the perpendicular and secure alignment, which is essential for smooth operation of these large surfaces. The hinges wont be fitted finally until after the flaps are finished in glass cloth so thats it for now with these parts. Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted January 7, 2013 Author Share Posted January 7, 2013 With the hinge mounts fitted into the flying surfaces the same had to be done for the outer wing panels, again ensuring accurate position and alignment. Once fitted with epoxy, these were sanded flush with the wings lower surface and sub T/E. With the work complete, I couldn't resist a dry fit - everything aligns nicely and the hinges are a good push fit into the grooves... ...and with the aileron fitted too the wing outers look almost complete. In fact they still need slots cutting for the 1/4" ply dihedral brace, servo wells are still to be positioned and cut for each flap and aileron, and the curvy drooped wingtips are still to be made and added to the balsa sub tip... a bit more work yet! Quote Link to comment Share on other sites More sharing options...
bouncebounce crunch Posted January 8, 2013 Share Posted January 8, 2013 Top stuff there Phil. really enjoying your build blog. This is one of the reasons I enjoy this website so much, there is many styles of building with plenty of great techniques and pics. do you have a maid to tidy up that workshop? bbc . Quote Link to comment Share on other sites More sharing options...
Matt Jones Posted January 8, 2013 Share Posted January 8, 2013 This is rubbish, where are the rivets?!?!?!Seriously, nice work Phil. All fits together really well. Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted January 12, 2013 Author Share Posted January 12, 2013 I wanted to get the aileron and flap servo boxes fitted before we join the outer panels to the inner panels this weekend. First job was to make 4 more balsa boxes to suit the Savox servos Im employing in the wing. Quite a quick job with a wicking cyano. With the boxes made up, I positioned them relative to their respective flying surfaces just behind the central wiring loom channel which had been cut in the foam core and marked on the surface. Positioned here the required control rods will be relatively short which is a good thing for servo slop and robustness. Happy with the position I set about creating the required cavities in the foam, each 30mm deep... ..and the boxes can be pushed home, secured with 5 minute epoxy. I broke through the hole positioned in each box into the central core wiring channel... now these just need sanding back to the wings surface and they are complete. I will make up hardwood servo mounts and light ply servo covers for these as some point in the future. Edited By Phil Cooke on 12/01/2013 08:59:18 Quote Link to comment Share on other sites More sharing options...
Matt Jones Posted January 12, 2013 Share Posted January 12, 2013 Very neat Phil, I'm looking forward to seeing the panels being joined. Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted January 14, 2013 Author Share Posted January 14, 2013 It's time to join the inner panels to the outer panels at the required 7 degrees dihedral. I can't put it off any longer... Not too much progress tonight - I have cut out some heavy duty wing joiners from 1/4" birch ply, but the rest of the evening was spent building a dihedral jig and testing the wing panels dry fit alignment before any slots are cut for the joiners and any adhesive is mixed... joining wings is a job I always worry about, you need to have everything ready and double checked before you commence the task. The inner and outer wing panels had been cut with their mating sections angled at 3.5 degrees each. With the complication of the wing joiner box running right through the inner panel and protuding a few inches into the outer wing, this meant that good alignment of the sections could not be achieved with the inner wing panels lying flat on my bench - both inner and outer panels needed raising by 3.5 degrees about the join. Hence the jig which was made to suit from hard balsa. Trig suggested 3.5 degrees required 55mm at the tip and 26mm at the root. The 2 piece wing jig was taped to the bench ensuring datum alignment and the wing panels were dropped on. As the wing sections underside is not flat the axial positioning (although not critical) needed to be repeated on the 2 wings so it was all measured up and once I was happy that everything was correctly positioned a few marks were made on the jig and the wing to ensire a matching pair can be produced. The wing joiners are beefy - see below - they will extend 9" into the inner panel, glued firm to the wing mount box, and extend 10" into the outer panel. They are sized so they sit just sub flush to the wing surface, they will eventually be capped with balsa and sanded to the aerofoil profile. With the wing correctly aligned on the jig the next job was to mark and cut the joiner slots in the panels... work continues... Quote Link to comment Share on other sites More sharing options...
Matt Jones Posted January 14, 2013 Share Posted January 14, 2013 That's a great bit of jigging, I hadn't realised it wold be so complex. One question though, why didn't you make the joiner so that it was thick enough to tie in the wing skins too? Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted January 14, 2013 Author Share Posted January 14, 2013 I can still make the joiners full depth if you think this is necessary Matt - I've cut them as they are now so I don't have the battle of sanding back the hard 1/4" ply against the veneered surface when they are in. I was assuming that the joiner as Ive cut them would distribute the loads well enough into the wing cores without them needing to ajoin to the skins - they are 2" deep after all - a huge surface area which will be bonded into a foam channel with slow setting epoxy, then capped to the wing surface. Are you suggesting that might just pull out under flight load as it is only as strong as the foam if it is not bonded to the skins as well?? You've got me worried now... Quote Link to comment Share on other sites More sharing options...
David Gilder Posted January 14, 2013 Share Posted January 14, 2013 I dont think there will be a problem Phil. I gather that the balsa capping will only be as thin as the wing veneer anyway! 2 inches is a huge surface spread over a total of 19 inches which shouldn't put the panels under any extreme stresses even in flight! When you look at the size of the joiners on trainer aircraft wings only 1 inch or so deep and only a few inches into the foam panels.. and they put up happily with the over stressing a beginner puts in from over pulling! Go with what you have planned. Quote Link to comment Share on other sites More sharing options...
Matt Jones Posted January 14, 2013 Share Posted January 14, 2013 Sorry Dave, I disagree and have a strong opinion on this one.Phil, if you haven't glued anything in I'd make them deeper to mate with the skins. It's these that give the panels their strength and carry/transmit flight loads and personally I wouldn't do this without bonding everything together. The Canberra has similarly large outer panels with full depth 1/4" spars and you've seen how that gets flown. I just don't see how foam alone, which is flexible, will be enough. You can always protect the veneer with masking tape or thin card while you sand off most of the excess.I often go overboard with things so maybe ask Si for an opinion in case I'm worrying unduly? Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted January 14, 2013 Share Posted January 14, 2013 I'd just stick 'em on with velcro Phil, they will be fine Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted January 14, 2013 Author Share Posted January 14, 2013 The good news is the slots aren't cut in the wings yet and no glue has been mixed, so this can easily be made right... Im conscious this is an important part of the build and Matt I agree with what you've said about the foam/joiner interaction. Ill make changes to the joiners so they go full depth and go with your recommendation - I wont exit through the bottom skin, but will remove foam right down to it and bond the joiner from the top side to the bottom skins inner surface. On the top it will have to protrude and be sanded back. FYI - Simon agrees the skins should be integrated into the structure - he did suggest I could come down on thickness from 1/4" ply (as these already weigh nearly 1/4lb each) and this will increase significantly with the extra material needed to go full depth. Anyway thanks for the discussion/advise on this one... I will proceed with more confidence now... Im off to cut some bigger joiners! Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted January 17, 2013 Author Share Posted January 17, 2013 I've now cut bigger, full depth dihedral braces, using 3/16" birch ply instead of the initial 1/4" ply in an attempt to minimise weight gain - the new braces are now 80mm deep(!) and still 19" long - when fully seated in the wing this will leave just a 2 to 3mm amount of ply to sand back to the wing surface. I've also cut the first of the slots in the inner panel, a job I was a little apprehensive about with them being so deep but this has gone well and all the foam is neatly removed right down to the veneer on the undersurface. Piccies to follow shortly, but we are nearly ready to re-jig the wings and mix some epoxy!! Quote Link to comment Share on other sites More sharing options...
David Gilder Posted January 17, 2013 Share Posted January 17, 2013 All sounding good Phil. These early morning updates are keeping me going on nights currently! Quote Link to comment Share on other sites More sharing options...
Phil Cooke Posted January 18, 2013 Author Share Posted January 18, 2013 Quick status update after another couple of hours braving the cold in the garage this evening... I've cut slots in both the inner and outer panels now and tailored everything tonight ready to join the wings on the dihedral jig this weekend. The photo below shows the new improved full depth joiners, now 3/16th ply, and the 5mm slots I've cut in each wing panel to suit. The slots have been cut out full depth so the joiner will bond to the inner surface of the lower skins, you can clearly see the veneer in the shot below with all the foam removed... A dry fit of the joiner in the inner panel proves a good fit and you can see how the joiner is to be bonded up against the ply wing joiner box which runs throughout the inner panel. ...and here with the outer panel dry fitted - already supporting the panels weight with no glue added! Happy with the fit, the wing panels can now be re-jigged on the bench at the correct dihedral angle and the joiner can be permanently glued in place with slow setting epoxy. Quote Link to comment Share on other sites More sharing options...
David Gilder Posted January 18, 2013 Share Posted January 18, 2013 Very neat job Phil. That wing joiner doesn't half look small now when layed up on the panels!! Guess you will have lots of time over the weekend for building and sledging!!! Quote Link to comment Share on other sites More sharing options...
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