Lindsay Todd Posted January 8, 2014 Share Posted January 8, 2014 Totally agree BEB, but I do expect you to stress that wing properly now. Linds Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted January 8, 2014 Author Share Posted January 8, 2014 The sheeting needs to be checked now the glue is dry - have a good press around, it shouldn't move and there should be no "cracking" type noises - both of which indicate loose areas. I'm glad to report that so far all is secure. So now its on to applying the trailing edge sheeting,... To do this the wing has to be pinned back down to the board. The wing must be as flat as you can get it whilst this sheeting is being applied if you are to avoid building in a twist. The Clingfilm is there to ensure I don't glue the wing to the building board! This sheeting - at the very back - must overhang the ends of the ribs by a little so you have something to glue the sheeting on the lower side to when we come to do that. While that's drying we can move on to starting the other wing,... One advantage of building a smaller model is you can fit two wings on the board at the same time! There have been many comments about the fact that the plan only shows one wing. To be honest this isn't that unusual and doesn't really present a problem. If you want to reverse the plan you have a number of options: Trace the plan onto greaseproof paper, turn the paper over and use that as the plan. Put a blank piece of paper under the plan and pin prick the main features through the plan. Take the paper underneath out turn it over then play "dot to dot" and label it up. Rub the plan with parafin oil (this is the old traditional way!) this makes the lines visible on the back. If the plane has been laser printed (if not take a photocopy) turn it upside down and lay it on blank piece of paper then iron it - the heat from the iron will cause the toner to partially transfer to the blank paper. Take plan along to a photocopying place and ask them to scan the wing portion and reverse the image before printing. But do make sure their photocopier is 100% scale accurate - some photocopiers slightly change the size of the image - not good for us! One way to do this is to draw as accurately as you can a square of known size - say 100mmx100mm on the plan close to the wing. You can then check the size of this square on the reversed print. And there are probably others. But actually here its even easier than any of them - in this case, because the rib spacing is constant, and the wing is parallel, we can just build the port wing over the plan of the starboard wing! All we have to do is reverse the left-to-right order of the ribs and Bob's yer Uncle! Easy eh? If you examine the second photo above you will see that, unsurprisingly, I have opted for this solution. BEB Quote Link to comment Share on other sites More sharing options...
Plummet Posted January 9, 2014 Share Posted January 9, 2014 Posted by Vecchio Austriaco on 07/01/2014 22:28:23: Glass head pins - I don't see where the danger is - <snip/> You don't see it - you feel it - suddenly - when the head of the pin suddenly disconnects from the pin wire, and slides down it. The pin then becomes a thumb headed pin. The process generates quite a bit of noise that is not suitable for young or easily offended listeners. Yes, I use glass headed pins, but only for sewing. Fabric isn't as tough as building board. Incidentally, my beloved has discovered that T headed pins are used by home weavers, and so I am hoping to discover a new source for them - alternately, I will have to steal my pins back from her. Plummet Quote Link to comment Share on other sites More sharing options...
Vecchio Austriaco Posted January 9, 2014 Share Posted January 9, 2014 Don't want to disturb master BEBs thread - but a proper glass headed pin bends before the head comes off. If you go for Prym glass headed pins the head will never come off - other than you brake it by the use of plyers - its glass after all... What is dangerous and comes off are the look- a likes using plastic balls instead of glass. End of pin discussion, I use them, you don't need to VA Quote Link to comment Share on other sites More sharing options...
kc Posted January 9, 2014 Share Posted January 9, 2014 I am sorry VA but the warning I gave and Plummet confirms is that some glass headed pins shatter and the metal penetrates deep into the thumb. Could cause a nasty injury. There seems to be no way of knowing which pins shatter and which dont! Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted January 9, 2014 Author Share Posted January 9, 2014 Just a quick update tonight - nothing very interesting going on so no photos. I've completed the sheeting to the underneath of the starboard wing. On the port wing I've added the top spar, the aileron false trailing edge and the wing's leading edge, but all of that we saw first time through and its no different here except for being a mirror image! So it's coming along nicely - more tomorow when I'll probably be putting cap strips on the starboard wing - and maybe the wing tip along with sheeting the port wing. BEB Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted January 10, 2014 Author Share Posted January 10, 2014 The second (port) wing continues to move forward. I've added the shear webs and the reinforcing triangular pieces. The front top and bottom sheeting is also in place, the bottom drying as I write. I just have to add the trailing edge sheeting and its at the same point as the first wing. I'll then move on to capstrips etc. One thing I did do tonight I remembered to photograph the balsa block in the front first rib bay before I added the bottom sheeting,.... I put one of these in the first wing as well - but unfortunately I completely sheeted up the front (top and bottom) before it occurred to me that I should photograph it! This part is not really shown on the plan - but it is pretty important. This again refers to one of the questions Mouse asked regarding drilling the hole for the wing locating dowel. Without these blocks you would be drilling that hole through just 6mm of balsa leading edge, then just chewing up the two mating inner ribs. With this block you have something "meaty" to drill into and ultimately glue to! BEB Quote Link to comment Share on other sites More sharing options...
Gary Murphy 1 Posted January 11, 2014 Share Posted January 11, 2014 BEB,as a new builder it would be a vast help to me if you could post some close up pictures of built up TE,idealy from the side ,lookins at the ribs full on.I never really understand the best/proper way. Chamfer top strip?,chamfer bottom strip? no chamfers and just lay top and bottom strips together with minimal contact. Also i have noticed on the couple of initial "practice" builds OR "bin fodder" that the plans are not always exact at the ribs and TE position.I have found that to get the gap from rear of TE to very tip of rib the TE will need to move forward,then that makes the wing narrower and that can lead on the probs,i presume. Is there a "sweet distance" this gap sould be given the thickness of the TE material,hope that discription is understandable. Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted January 11, 2014 Author Share Posted January 11, 2014 Hi Gary, no problem, I will take some photos tomorrow to try to show what I'm doing at the TE. The actual length of true trailing edge is very short on this model - only about 4" of so - but it will show the principle well. I've been heavily engaged as "dad's taxi" today - first running my daughter to her friend's house (and back again) then being bounced into running my son back to university - 80miles away! So needless to say I haven't managed to get an awful lot done. I've been adding the TE sheeting to one side of the second wing, and then (while second wing was drying) I started the job of adding the cap strips to the first wing. For the cap strips we just take some 1/16" (1.5mm) sheet and cut 4 or 5 full sheet lengths at 6mm width or so. We then cut these to lengths very slightly longer than we need - 2-3mm longer no more. And so we end up with lots of strips that look like this,.... We then fit these to the top surfaces of the rib. Try for length then gently sand them to the correct so that they just fit between the front and rear sheeting. You need to be a bit fussy here - no gaps at the ends, to fully do their job they must be a touch fit along the rib and between the two areas of sheeting. Once they are the right length, apply aliphatic (or PVA) to the rib top and lay the capping on top and pin at the ends. Double check that it is in contact the full length of the rib, that its centralised on the rib (except at the wing tip end) and that it contacts against the front and rear sheeting. If it doesn't, take it off and start again. When you have them in place they should look like this,... So, what are they for? Well actually they do several important jobs: They bring the rib profile up to the height of the sheeting - otherwise we'd have a hollow in the middle of the wing! They provide the covering with a larger surface to glue to - the ribs are a bit narrow. Most importantly, they turn the ribs into I-section beams and join the front and back sheeting providing a route for the stress to "flow" around the wing. So, useful little devils - don't forget them or skimp on installing them. Take your time get them fitted right! BEB Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted January 12, 2014 Author Share Posted January 12, 2014 Right Gary, I've been doing the top side trailing edge sheeting on the port wing so I've taken the opportunity to take some photos to show how I'm dealing with the trailing edge. I don't claim this is the definitive way - other folks may well have other ways of doing this - but this is my way and it works for me. So, for what its worth I pass it on to you! Here is the sheeting on the underneath of the port wing in a view you will be familiar with - its basically the same view as I showed for the starboard wing,... Now what I didn't show - and perhaps should of (although I did mention it in the text) is that this sheeting is somewhat wider than the ribs themselves. This can be seen best from the other side - so turning the wing over we can see that the sheeting extends beyond the tips of the ribs,.. The reason for this is so that when we add the sheet on the other side we can apply glue to the ribs, but we can also apply glue to the portion of the sheeting beyond the ribs and then fasten it up like this,... The pegs are there clamping the back of the sheeting (the overhanging bits) together. Note the use of a two pieces of off-cut ply, between the pegs and the sheet, to spread the load across the sheet. Now switching to the other wing, where obviously I've already done this, we can see the effect from the side - well sort of, sorry its not a brilliant photo but I think you can see what I want you to see,... So the sheeting is stuck to the ribs and behind that it is stuck together to each other. To finish this what I will do is sand this edge back - closer to the ends of the ribs - maybe 2-3mm away. I will then sand the top sheet (because its a flat bottomed wing so all the curvature is on the top) so that I sand it away right at the very edge. So it will look something like the drawing below,... Ideally a TE should be "razor sharp" in practice with a purely balsa structure like this that isn't possible - it would be too fraglie - so we'll settle for this which will give us a reasonably thing but practical trailing edge. Note that cases like this are one of the few where aliphatic is significantly better than PVA. With this method we will sand very close - probably slightly into - the glue joint. Aliphatic has the advantage that it dries quite hard and sandable, whereas PVA turns into a horrible dirty grey rubbery goo when you sand it! Hope this helps. General progress report later! BEB Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted January 12, 2014 Author Share Posted January 12, 2014 Quick progress update then; All the wing sheeting - barring the centre which we can't do until the wings are joined - is now complete, front and back, both sides top and bottom and both wings! All the cap-strips are now in place - take a while that. The sheets for the wing tips are attached. So it all looks like this now,... Next up we need to add the reinforcing strips for the wingtips, hard points for rigging attachments and servo hatch fittings. We're getting there! BEB Quote Link to comment Share on other sites More sharing options...
Depron Daz Posted January 13, 2014 Share Posted January 13, 2014 Looking really good BEB. As I said before, I will be using this excellent build log as reference for mine when it finally comes around. You have displayed and explained the build clearly and should help many builders of this lovely model. Nice one! Daz Quote Link to comment Share on other sites More sharing options...
Gary Murphy 1 Posted January 13, 2014 Share Posted January 13, 2014 BEB, Thanks for taking the time to explain the TE build up.I realise now a chamfer on the top strip is needed. In my case and whats confuses me is the lentgh odf ribs i had were shorter than the plan so i could off moved the TE in to get gap again but that makes the wing narrower OR as i did left the TE in the same position with bigger aft gap behind ribs BUT that made my TE VERY thin indeed,too thin. When you say you lastly sand back to 2-3mm to the ribs does that not effect the width if you built to the TE plan line? what would happen if the kit hade profile of wing already cut in fuse sides? Sorry to take up your time on this but it looked the ideal time to learn. Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted January 16, 2014 Author Share Posted January 16, 2014 Hi Gary, in practice you trim the TE back to fit the fuselage. In my case a trial fit tells me that as it is the wing is very slightly too wide - but only by 1/8" or so. Therefore I'll only need to take the TE back a short way. Well, I've had a busy couple of days in work so nothing done Tuesday and Wednesday! But I did get a bit done tonight. First up I added the mounting rails for the aileron servo plates,.... These have to be set at the correct height so that the servo cover will finish flush with rib cap-strips. Five minute epoxy is the adhesive here - nice and tough but goes off fairly quick so convenient. Talking of things being flush, there is a little problem here. The lower edge of the servo cover will be up against the rear spar - but with the cap strips fitted the top surface of the spar is 1.5mm below the surface height. So if we do nothing we will have a funny hollow there. We need a lifted edge to fix the covering to, so let's have one,... That will give me something to stick the Solartex to an make a nice boarder. So let's see what the servo covers look like in place,... Not too bad - but I think I'll have to find some better fastenings than those black screws - they'll show up like a baboon's bum once the covering is on! Next its the installation of the hard-points for the rigging fixing screws. The rigging is of course purely cosmetic so these don't have to be mega-strong - but we do need to be able to screw into them firmly. They need to be more or less flush - ever so slightly below - the cap-strips,... Again the adhesive is 5 minute epoxy. Now we fit the bracing pieces to the wing tips,.. We don't glue the last 5mm or so as we'll need to trim this away when we fit the wing laminations around the edge of the wingtips. Soon we'll pare the excess away and sand these. Talking of the edging laminations these are made from strips 3x3mm and have to bent around the profile of the tip. The way I am doing this is to thoroughly wet one side of the strip easing it into a bend, then fasten it around a former - in my case a roll of masking tape!... Once this dries we can take it off the tape roll and we have,... It will be a lot easier to fit that than it would have been to fit the "raw" strip! And that's the next job. BEB Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted January 16, 2014 Share Posted January 16, 2014 Lovely neat work BEB and nice clear instructions too Cheers Danny Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted January 18, 2014 Author Share Posted January 18, 2014 Thanks Danny Well - I am a complete and utter dork! What a whally! Above I stripped some balsa and curved it for the wingtips. I knew it had to be 3mm sq - I put in here that it was 3mm sq. But what I did was strip some 1.5mm (1/8" sheet! So those strips are 3 x 1.5mm not 3mm sq. Idiot! So I had to redo them - not much point in making another 4 of the small ones and laminating because its just the same about of work to make 4 new ones the right size. Of course true 3mm sq is a bit harder to bend without snapping it, so I had to do this a slightly different way. This time I soaked the whole strip in water - as opposed to just wetting the outside of the bend - for about 2 hours. Then I formed them "free-hand" on the building board with the help of lots of pins,... That gave me four of these,... So, back to business. Time to introduce a new tool, all the way through so far I have only been using the tools I showed at the the beginning of the blog, but now I've used one of these,... Its a razor plane - sometimes called a David plane after the company that makes this particular one. A very handy tool for rough shaping because its fast, easy to use and makes a lot less mess than sanding - shavings are easier to clean up! It can turn the wing tip bracing pieces from this,... Into this,... In less than 30 secs! Effortless. Well worth investing in. We will also use it to help shape the wing leading edge later. So, time to fix these curved "rims" on the wingtips,... And we can now take out the Permagrit and do a bit of general shaping around this area. Which gives us,... Note the curved profile applied to the edging. In one or two places the 3mm sq stuff was getting a bit thin - and so I locally reinforced it with some pre-bent 3 x 1.5mm I just happen to have lying round - I wonder where that came from Shhhhh! So, both wing tips done,... Well that's it for now - next up is fitting the aileron servos so I don't forget them and sheet the centre without the servo leads! BBE Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted January 18, 2014 Share Posted January 18, 2014 Hi BEB, you might want to give ammonia a go, I know the whiff is a bit much You can bend it within 5 minutes of soaking and force dry with a hairdryer. It curves a lot more than just using water as well, because ammonia breaks down the bonds between the fibers, water just relaxes the wood and has no effect on those bonds Looks really good though, lovely job. Just pushing my Apache aside and getting the BiStormer (mass build) drawings onto the board..... better not take more than a week! Need to get back on the Red Indian Cheers Danny Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted January 18, 2014 Author Share Posted January 18, 2014 What you describe as a "wiff" Danny nearly got me divorced a few years back. I wanted to build up some laminated edges for the tail surfaces of a biplane. As I needed some very tight bends in quite a lot of strips I decided to chuck them in the bath - with some ammonia to help things along. Mrs BEB was not happy about me using the bath - she was a damn sight less happy about the "wiff" pervading the upstairs rooms of the house! Since then - whenever possible - I've stuck to using just water. The "dinnerlady" is not a force to be trifled with! BEB Quote Link to comment Share on other sites More sharing options...
Phil Winks Posted January 18, 2014 Share Posted January 18, 2014 Nice work Dave and as has been said earlier a very well written and informative blog. I have to agree with you, its always best not to mess with the dinner lady Quote Link to comment Share on other sites More sharing options...
Plummet Posted January 18, 2014 Share Posted January 18, 2014 Posted by Phil Winks on 18/01/2014 17:41:14: I have to agree with you, its always best not to mess with the dinner lady ---WARNING Off Topic WARNING--- I have a couple of points/queries regarding the current theme of this discussion. I am the one who does most of the cooking in this household. Does that make me the dinner lady? My building cellar has been out of action for a considerable time because we have been having a window replaced, and an extractor fan installed so that the dope fumes should not creep upstairs - because SWMBF* can't stand the smell. Since this involved compressing everything at one side of the room, and we then went to a club auction and got some more kits and 'no-hope of ever being fettled but they were cheap' models which had to be stuffed in as well, it is taking me an age to sort it all out, so I am not doing any building, so there is no chance of any dope fumes for quite some time to come. Ho Hum Plummet * SWMBF - She Who Must Be Fed Quote Link to comment Share on other sites More sharing options...
Phil Winks Posted January 18, 2014 Share Posted January 18, 2014 Just to stay of topic for one second longer Plummet, I must commiserate with you and your lack of opportunity for dope fumes any time soon, I don't know about you but I'd be suffering withdrawl by now Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted January 18, 2014 Author Share Posted January 18, 2014 Thanks Phil - Plummet mate, my heart goes out to you. The question is of course was it a cunning plan on behalf of SWMBF or was she just "lucky" - Mmmmm? Well a bit more progress this afternoon, aileron servos installed. This is probably pretty familiar territory for nearly everyone so I'll mainly let the pictures do the talking here. First we need something to fix the servos to,... The adhesive is 5 min epoxy again. The blocks you are going to screw into really do need to be hard wood - not balsa. (Yes I know that balsa is technically a "hardwood" but its not a hard wood IFKWIM!) Don't forget a couple of triangles underneath just to increase the glue area and make everything a bit stronger. Here's the servo in place,... And then fitted to the wing,... And from the underneath,... Well both of those are now done - and BTW while the epoxy was setting, and we were chatting, I've sheeted the fuselage rear - no details as its exactly the same process as sheeting the nose,... Well, there is no getting away from it - the next job is the one we all hate,...joining the wings! BEB Quote Link to comment Share on other sites More sharing options...
Vecchio Austriaco Posted January 18, 2014 Share Posted January 18, 2014 ...and this will show if the hole in the wing plate matches the position of the hole in the wings! Did you drill it already? and it will probably show that the wings are 3mm to wide for the wing plate (this is what they did in my Dawn Flyer...) looking forward to your next post VA Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted January 20, 2014 Author Share Posted January 20, 2014 No VA - I haven't drilled the hole in the wing yet - I'll drill it where it needs to be once I trial fit the wings to the fuselage Wow - you are a bundle of happiness about this - do I sense some traumatic experience with the wings here VA? Or did Austria lose at football to Germany! OK onto the moment all builders approach with trepidation - joining the wings - make or break time! First preparation is everything here, first lay down some plastic sheet - we do not want to glue the wing to the bench!... Next place the wing that has the bracer already glued in place on the bench - right way up. Lift the wingtip and press the bracer down to the bench surface. Like so,... The front sheeting is hanging over the edge so the first rib can sit flat on the board and all the others are elevated but parallel to it. Having cut the first two ribs, dry fit the other wing so it is completely flat on the building board. Once you are happy with the fit, assemble everything you will need; glue (use 1 hour epoxy here - we need the time), paper towel, coffee stirrers to both mix and apply the adhesive and of course lots of clamps,.. Mix your epoxy and away you go. We can take our time here, fiddling and adjusting until we are happy. Then clamp and pin everything up,... I've left the heater on in the workshop - the outside temp tonight is about 3C - this epoxy will never set at that temperature. I'll check on it before going to bed - hopefully it will be well on its way by then. BTW I find that 1 hour epoxy never sets in 1 hour. Maybe it would at 25C but at normal workshop temps - say 15-18C its touch dry after about 3 hours, but not completely set until maybe 24 hours. Similarly 5min epoxy seems to take about 15 mins to go off and maybe 1 hour to really set. BEB PS - I forgot to mention - I had to remove the aileron servo from the port wing (the one lying flat) or you can't get it to align probably - advantages of trying a dry fit first! Edited By Biggles' Elder Brother - Moderator on 20/01/2014 21:23:05 Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted January 20, 2014 Share Posted January 20, 2014 Looking really good BEB.....you have quite inspired me...I quite fancy building one myself. I dug the mag with the Dawn Flyer in for a quick look last night.....why oh why has Lindsay put the servo arms through the top surface of the wing??? Surely they'd be better through the bottom surface or have I missed something?? Quote Link to comment Share on other sites More sharing options...
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