Danny Fenton Posted February 17, 2014 Author Share Posted February 17, 2014 If it flies at all with this shoddy workmanship, it will be amazing...... When I check the lateral balance I may need to add a little ballast to a wing tip, but I doubt the weight of a couple of anchor nuts and a small dollop of epoxy will alter things too much. It is unnecessary weight and that annoys me But at least I am still on the green Cheers Danny Quote Link to comment Share on other sites More sharing options...
kc Posted February 17, 2014 Share Posted February 17, 2014 Full marks to Danny for showing us all how to get out of trouble. It is very reassuring to know the experts get it wrong sometimes.Knowing my luck I would hack into the wrong wing and move the 'good' part to the wrong position and be in double the trouble!I suppose the lesson to be learnt is to get the model straight and correct aerodynamically whatever it does to the looks of the model. But no doubt Danny will repair the damage so we 'can't see the join'......lets all watch how it's done and take note because sooner or later we all have this sort of sheet balsa repair to make. Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted February 17, 2014 Author Share Posted February 17, 2014 "Knowing my luck I would hack into the wrong wing and move the 'good' part to the wrong position and be in double the trouble! " Had to check I hadn't gone and done just that KC Phew I hadn't! I wish you wouldn't keep calling me an expert lol I am just bumbling along like everybody else Anyway the repairs to the upper surface took seconds, as if you look carefully the sheeting was cut off with heavy chamfers and I used a scalpel. This means no wood is lost, and the chamfer gives us a lip to glue the cut off pieces back down to. here is the wing after the repair can't see the repairs? How's that Nigel, have I avoided dropping a shot Cheers Danny Quote Link to comment Share on other sites More sharing options...
kc Posted February 17, 2014 Share Posted February 17, 2014 A hole in one? Very neat.I remember lifting a floorboard something like that when we had a pipe leak! Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted February 17, 2014 Share Posted February 17, 2014 I can see it Danny its just a pimple, not big enough to be a wart Quote Link to comment Share on other sites More sharing options...
Nigel Day Posted February 17, 2014 Share Posted February 17, 2014 Down in par Danny, nice work. If mine looks that good, with or without the 'trapdoor', I'll be very pleased! Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted February 17, 2014 Author Share Posted February 17, 2014 Posted by john stones 1 on 17/02/2014 18:03:50: I can see it Danny its just a pimple, not big enough to be a wart Don't you mean I can see them John, there are two hole repairs, do you only see one? Cheers Danny Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted February 19, 2014 Author Share Posted February 19, 2014 The cabanes have been attached after having checked that the wing holes now lie on the flats. I will drill them next. What have peeps done with the cabanes? I am tempted to round them off a bit... I am not joking the fuselage has doubled in weight with the addition of these chunks of metal Cheers Danny Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted February 19, 2014 Author Share Posted February 19, 2014 Once the cabanes are fixed to the fuselage then we can set the top wing upside down on a foam pad and then allign the fuselage and wing. I use some kevlar chord from the tail post to the wing tips to make sure the wings are true. I use a piece of tape wrapped over the chord, this can be slid along the chord to make the measurement. Here you can see strips of A4 attached to the wing with masking tape. A BBQ skewer is pushed through the A4 into the wing bolt holes in the wing. This is a very similar idea that is often used to allign fibreglass cowls. The fus is once again placed over the wing and checked for true again with the chord. The paper slips are positioned over the cabanes and the holes position transferred to the alloy cabanes. These are then drilled. The allen headed bolts are fitted through the holes and bolt the wing to the cabanes and fus. Cheers Danny Quote Link to comment Share on other sites More sharing options...
kc Posted February 19, 2014 Share Posted February 19, 2014 A very neat way to mark the position.But what stops the bolts crushing the balsa when tightened and changing the incidence? Or is that ply instead of balsa or is there possibly some tube as a stand off? Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted February 19, 2014 Author Share Posted February 19, 2014 Hi KC, you are quite right there is only balsa above the ply plates. The plans show that the cabanes are recessed into the balsa skins so that they are flat aginst the ply plates inside. The cabanes is much thicker than the wood so they won't be fully recessed, only partially. I will draw around the cabane "feet" and remove the balsa to make this happen Cheers Danny Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted February 19, 2014 Share Posted February 19, 2014 its looking good Danny very tidy work, I like outer stringerlongerons they add character to the fuzz love tips you add in, its good stuff had seen both holes, was trying not to be too critical Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted February 19, 2014 Author Share Posted February 19, 2014 Thanks John Bit more done this evening, but first a morale boosting pic from earlier.... The wing sheeting was routed out KC so that the cabane sits on the underlying ply This little slither of 1/8 sq all around the cockpit/cabane area is F26, it took some figuring out but I got there in the end. I also sheeted in the area where the pilot will be sat. The sheeting that covers the cockpit area is 3 1/2 wide so had to add a bit to some 3" wide 1/16 A bit fiddly and there are one or teo gaps down the side, but it is attached securely to that 1/8 F26 so the gaps are aesthetic rather than structural. Will take a look at the nose section tomorrow, need to create a battery tray of sorts and a hatch type afair Cheers Danny Quote Link to comment Share on other sites More sharing options...
kc Posted February 20, 2014 Share Posted February 20, 2014 .Are the mounting bolts steel or are nylon to be used? And would you advise everyone to use steel or would nylon be better for the newer pilots? Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted February 20, 2014 Author Share Posted February 20, 2014 Hi KC the bolts are steel. The plan also indicates steel bolts, I hadn't even considered nylon to be honest. I usually find that if a model crashes badly enough for the nylon bolts to shear the rest of the model is pretty badly damaged. I nearly always use steel. Good point though Cheers Danny Quote Link to comment Share on other sites More sharing options...
kc Posted February 20, 2014 Share Posted February 20, 2014 On other models the usual way is a dowel at front ( or two dowels) and 2 nylon bolts ( maybe only 1 ) In a typical wing catching ground incident I have noticed the dowel pulls out and the nylon bolts shear ( observing other peoples accidents of course! ) So I think 'nylon' bolts do work but it depends on circumstances. Wing bolts come in two types -SLEC do two types, polyprop which breaks more easily than nylon which they say is tougher and virtually unbreakable..Whether the Bistormer and Barnstormer would benefit as they dont have a dowel to slide out is debatable. They would need all 4 bolts to break to have any benefit. I just wonder if the strut to fuselage bolts would be better in polyprop type. It might break the top fuselage sheeting away too but this might be easier to repair than a wing. It depends a bit on whether you prefer to repair fuselage or wing but newer pilots or those with rough flying sites might consider this idea.Nylon or polyprop bolts are a bit of a pain to insert to the underside of a wing and anyway they tend to crossthread easily because they are a tight fit even when correctly inserted so you often dont know until the thread has chewed itself a bit. But nylon never vibrate loose during flight. So steel bolts in a Bistormer or Barnstormer wing seem easiest to assemble the model. And I think I will build a Barnstormer with steel bolts into the wing but polyprop bolts in the fuselage. As it will be electric the vibration problem should not occur - I hope.Edited By kc on 20/02/2014 14:06:42 Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted February 20, 2014 Share Posted February 20, 2014 It's a fairly big build Danny, but you can see the satisfaction you get from it as it really takes shape. Definitely a keeper. Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted February 20, 2014 Author Share Posted February 20, 2014 Thanks for the information KC, I wasn't aware of the two types of bolt. As I am usually building a scale model, I push to hide everything, and it is easier to hide a steel fixing than plastic. Its shocking to say but I rarely repair a model, unless the damage is very slight. Hi Colin, I like shaping balsa, the bits I don't enjoy are making metal work fit, and installing radio gear. But unfortunately these things have to happen. This model is designed to have a couple of dowels pass through the fuselage, just ahead of the leading edge and behind the trailing edge. Rubber bands are then used to fix the wings. This is a fine way to attache the wings and is also the way that the undercarriage is attached, this entailing an additional dowel ahead of the leading edge one, and the two used to hold it in place. I am not going to use rubber bands in this instance as they can cause trimming issues if you don't allign the wing exactly the same each time you fit it. I prefer a couple of dowels in the wing leading edge and one or two bolts in the trailing edge. This is a slow flyer and therefore I will probably two dowels and a single bolt. One of the jobs I hate is trying to fit dowels to wing leading edges accurately and then making corresponding holes in the fuselage. I stared at the problem for a few moments and have come up with this method, it is an extension of the paper allignment used on the cabanes, that I showed earlier. First of all we tape a piece of paper to the wing leading edge, and make holes where we want the dowels We then continue the paper around the leading edge and tape it down on the other side of the wing. Position the wing aacurately back on the fuselage Peel the tape up to release the paper from the wing underside. Bend the paper forward keeping it taught, and affix it to the fus with fresh tape Now carefully lift the wing from the seat, and unpeel the tape from the wing upper surface. And stick the paper down inside the wing seat opening. Put the wing aside for now Keeping the paper flat against the wing seat bulkhead, transfer the position of the holes. Ditto drill the holes for the dowels, the holes need to be a nice fit, not to snug and definitely not too lose! Two wing dowels were made up about an inch long. Each had one end radiused slightly by putting the dowel in a drill and sanding it while spinning The holes in the wing leading edge are deliberately slightly loose, the area where I don't want epoxy to get is covered in a layer of my plan protector, and the dowels snugly fitted so that they just go through the bulkhead and past the radiussed section. Epoxy is spread over the dowels and inside the holes in the wing. The whole lot is then assembled, some weights are used to keep things still while the epoxy sets. Never seen it done that way, quite pleased that this old brain figured that out Cheers Danny Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted February 20, 2014 Author Share Posted February 20, 2014 Struggled all evening trying to position all the mechanical bits, the battery pack fits where I hoped, but is just a bit taller than I wanted. I had two ideas for the front end one was simple the other was difficult and involved making a dummy engine, or at least a cylinder or two. Of course the pack being slightly taller may mean I have to adopt the latter Cheers Danny Quote Link to comment Share on other sites More sharing options...
Dave Miller Posted February 21, 2014 Share Posted February 21, 2014 I see that you intend using a very small propeller. Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted February 21, 2014 Author Share Posted February 21, 2014 just goes to show how plans can change. I felt I was backing myself into a corner so ripped all that apart. I know this motor and 6S A123 will go vertical on an 11 x 7.... not that I want that, but it is a known baseline. So I have torn the pack apart, added another cell and made it into a more useful shape. This is the conventional shape I use in many models. You can see that even though it is one more cell, it gives us more options when positioning. It also means I can slide it back, as I am am already worried about the c of g even with a 1" shorter nose. Cheers Danny Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted February 21, 2014 Share Posted February 21, 2014 Lots of food for thought here. Quote Link to comment Share on other sites More sharing options...
kc Posted February 21, 2014 Share Posted February 21, 2014 That's an ingenious and clever idea for wing dowels and just at the right time for me...I have a (different) model needing dowels next week. Seems to beat the idea of drilling the hole too low (or high) and filing until it's a good fit.Could you state the motor and battery details please. There seems such a variety of motors & constant change of availabilty that it's hard to choose what to use. Quote Link to comment Share on other sites More sharing options...
kc Posted February 21, 2014 Share Posted February 21, 2014 Dave, I think it may be rather like a ducted fan! Quote Link to comment Share on other sites More sharing options...
Barrie Dav 2 Posted February 21, 2014 Share Posted February 21, 2014 What are you going to use for wheel axles Danny? I had one of these in the 1970's (Merco 49 powered) and although I used stainless steel stubs they did not take kindly to the rough landing strip and bent. Quote Link to comment Share on other sites More sharing options...
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