Geoff S

Not much to show today. Before I can fashion the wing centre section and the canopy I need to have the fuselage outline straight so I've made a pair of 0.8mm ply doublers to fix inside the fuselage around the wing seat. It extends from F2 to F3. At the moment it's clamped by nearly every clamp I own whilst the Titebond goes off. I'll leave it until the morning. I've started the canopy by cranking a piece of 3mm balsa for the floor. The join is a small piece of lightweight glass cloth and thin cyano. I've made a pair of balsa sides which will lift the bottom of the clear canopy higher at the back than the drawing shows but nearer to scale. I notice Nigel's finished models look closer to scale than his drawing so perhaps he did the same. Mine will be launched using a dolly because I can't throw. I never could very well but a high spinal injury has made it much worse. Geoff

Posted by pyro stu on 12/03/2013 10:15:40: Hi Geoff thanks for that i found that one as im on that forum. what was your under cart like i found it so c**p i changed it to a hangar 9 carden yak set. well i hope to test fly this weekend weather depending I made a new one out of dural which has survived OK. I breoke the original on one of my rare poor landings with this plane. It's lovely to fly. Geof

Posted by Romie Haslam on 12/03/2013 11:03:41: . Been snapping a lot of props in the cold weather but since I played with the speedo to get hard brake mode I can stop it level with the wings now and its great havent snapped one since. Romie. I'm also not fitting an undercarriage but I will probably use a folding prop to minmise damage on landing. I like to keep the prop rotating slowly to act as an airbrake so a hard brake would make that impossible. Geoff

Posted by LMA Dave on 11/03/2013 00:18:53: Hi Pyro / Geoff, yes you are right Geoff it is a Maher's Thunderbird, I haven’t got round to finishing it yet, Pyro, I have very limited instruction on the model I will try and fine them and let you know if it has the info you want. There was very little provided. I still have all there was. Just 2 sides of A4 in very big print. CoG is on the wing spar. Control throws are an inch both ways for everything. 3degree down thrust and 3 degrees right thrust. Standard servos throughhout (JR 591) though I used a big 1/4 scale servo on the rudder because I had one in stock. Flies brilliantly - I;ve had numerous flights with mine - probably 100 at least. My build log is at RCMF somewhere. I built it in 2007 but the forum has been reorganised since then. The instructions are here http://www.rcmf.co.uk/4um/index.php?topic=54262.0 Found it but the pictures don't show probably because of a system crash that messed up the whole forum a few years ago. The pictures are still on-line in my gallery but don't appear for some reason. http://www.rcmf.co.uk/4um/index.php/topic,36928.0.html   Hope that helps. Geoff Edited By Geoff Sleath on 12/03/2013 00:52:43

Thanks Colin. I've probably got some spruce laying around and may even have some carbon tubing which would be very fancy Been flying toy (ie fixed pitch, I'm not a heli person) helis all morning and trying out my newly arrived V911 so not got started on woodwork yet. Did a copy of the April RCME as well. I quite like Mr Miller's new plan, so perhaps I'll be building a bit more after the Tucano. I don't know how I manged to find time to go to work Geoff

Posted by WolstonFlyer on 11/03/2013 15:37:38: My F1a is 2 x 3mm ply epoxied together, this gives enough thickness for the T nuts to fit into with their spikes gripping into the wood. I used 3mm Socket Head bolts and "T" Nuts from SLEC I wish I'd done that in retrospect. The nuts are very fiddly to get into place. F1a certainly needs a bit of shaping at the top to get the line of the nose right. I don't know how you manage working in the kitchen. I have enough problems with dust and shavings in my workshop and SWMBO isn't too keen on my treading it into the lounge carpet when I emerge from my man-cave Though she is very supportive and tolerant of my hobbies as I am of hers. btw I posted a picture of my workshop in the appropriate section a few days ago. Geoff

I haven't any problems with CNC cut fuselage sides being difficult to pull in. As regards the turtle deck at the back, I added 5mm to the fuselage sides before glueing the triangular stock onto the inside. It's worked out quite well and I seem to have got the right angle because the CNC fin front piece is just about the right angle to meet the fin and the fuselage. I didn't see any post by Nigel and just went ahead - brave? I agree about sanding off the all the burnt wood from the laser cutting. It does make black powdery finger marks on the nice new wood, though, if you're not careful. I'm making a removable wing so the centre section is separate from the wings themselves (see Phil Winks' drawing). Out of curiosity I weighed them last night after shaping. One was 75 gms and the other 76 gms. Is anyone doing anything to make the L/E ding proof? I've been wondering whether to glass cloth them using Poly C or even just applying a coat of wing skinning epoxy (no cloth) just on the front. In the original article Nigel writes about aileron hinging. He offers either chamfering (which I take to mean top hinging) or the more usual trimming to a centre point. I prefer the former and I've used it before but not when using torque rods just when having wing mounted servos. Will the torque rods work OK with top hinging? I don't want ruin the ailerons and have to make more. Geoff

Posted by pyro stu on 10/03/2013 20:08:10: Hi Dave in the 3rd pic down you have a model i was givin but mine had no info on or in the box can you tell me the make of the model so i can get the info like throws & cofg & power. & what they fly like mine has a 180fs up front waiting for the good weather to get here to try it out cheers Stu I'm not suren what it is but it looks a lot like a Maher's Thunderbird. I have one with a Zenoah 26 petrol engine. Geoff

Posted by Colin Leighfield on 10/03/2013 22:48:30: Fair enough Phil, though it certainly isn't immediately obvious! I did see the photos and that clearly is an accurate scale model, the colour scheme is an attractive choice. I remain cautious abouy flying mine in company with a load of others in the same colours, so I'm going to bend the rules and do something different. That's a good point. I used to race 1 metre yachts and mine had a red hull. On several occasions, when the fleet was on the other side of the pond where we sailed, I found I was 'sailing' the wrong red-hulled yacht. Not such serious consequences as with a aeroplane In my searches I noticed a Tucano was painted in a BoB Spitfire scheme on one of the anniversaries so that would be both different and accurate to scale. Geoff

Well I've done my bit for entropy by creating copious amounts of balsa shaving and dust whilst carving the wings. Not as difficult as I feared but, like the proof of the pudding is in the eating so the proof of the wings will be in the flying. For those using the CNC cut parts I suggest separating the ailerons from the trailing edge, cleaning off the burnt balsa from the laser cutting and tacking back in place with a few spots of Cyano to make the razor planing easier. I've also made the wing dihedral braces. As you can see from the picture, I still have the centre section to make and then there're the torque rods and servo to fit. Not sure how I'm going to attach the wing. There's Phil Winks' method which seems to involve a lot of weighty 1.5mm ply but looks like it should work well and possibly provide the basis for a battery support. Then I'm considering 5mm bolts front and rear - 4 in all - without the usual dowel or ply tongue. The width of the underside of the fuselage is adjustable to some extent because as it stands it's slightly concave but can easily be squeezed straight. Phil's mounting plate would certainly overcome that tiny difficulty. This is my total progress so far. Less progress tomorrow because I'm going helicoptering tomorrow morning - indoors and I'll take the opportunity to get the latest RCME and see what Nigel suggests. The trouble with being retired is that there aren't any holidays - 24/7 work Geoff

I'm not sure that the wire frame image is not of the original aeroplane but a model. The prop doesn't look quite right and the exaust outlet is too high. The exaust ends come out slightly below the bottom of the fuselage on the full-size - if I fit some on my model I intend to position them a bit higher as I'll be belly landing it. Of course, I may be wrong; it has been known on very rare occasions, though my wife would deny the 'rare' and the 'very'. Back to wing carving Geoff

That looks neat. If you look at my similar picture on my build thread I've had to cut some meat from the triangular stock to allow easy access to the motor mount bolts. I think I'll include a top hatch as in the original drawing to allow access after the build is completed, just in case. Your prop driver looks about the same as mine - ie about 6mm thick. Will you have sufficient space for a 10mm spacer ring? Geoff

Posted by Bob H on 09/03/2013 20:18:26: No need when flying electric. What happens if you lose your plane for a while in the ground ? ( with the failsafe set) Your motor will keep running until the battery is flat and you would probably require a new motor after . The prop will just keep on turning digging a hole. If any model needs a failsafe function that cuts the throttle, it's an electric one ... and that's for the sake of the operator as much as innocent bystanders. After all, I've never seen a model with an ic engine burst into life without warning (all too often they won't burst into life when you want them to) but an electric model can. A 12x6 prop powered by an electric motor is more dangerous than an ic powered one because an electric motor continues delivering torque, even when stopped, right up to the point the smoke escapes. After all it may be your arm rather than the ground it's digging into. I always set the failsafe and, in addition, I've programmed a throttle hold switch on my Mux 3030 so that inadvertent operation of the throttle control won't start the prop spinning. I regard any electric model as potentially dangerous if there's a battery fitted. Geoff

Well, Wolston, I've been collecting tools for about 60 years so I'm likely to have a few around. They last a long time and I, like my Dad was, am a bit of a tool junkie. Most of them were for working on motor cycles (one of my 21st birthday presents was a Britool socket set I still have) then for racing dinghy maintenance and then pedal cycles before I tried aeromodelling. I'm not looking forward to carving the wing profile despite what Nigel says in his build article. That's tomorrow's job. Geoff

Posted by Mike Gunn on 09/03/2013 22:54:05: Your workshop looks nice and cosy Geoff. I love the feeling of being surrounded by my fave stuff and who needs a heater when you have a valve radio...lol Nice one.....Mike Thanks, Mike. I probably spend about 70% of my time in there when I'm at home. I'm either reading or working on something. I was brought up living behind the family radio & TV business and there was a huge workshop, so I got used to the idea from birth. Mine's tiny by comparison and I built it as an extension to the house not long before I retired. It's a lot warmer than the garage though my wife didn't mind me building bikes or bike wheels in the house if it was cold - especially if it was her bike or the wheels were for her. Geoff

Tim, you told me at Ashbourne you only did one job at a time. There are two models in both your pics . But it all looks incredibly tidy compared to mine. I took these just a few minutes ago. One from each end. The Murphy FM radio dates from about 1958 and still works once the valves have warmed. It'sa bit of nostalgia, really because I used to service them in the factory service department when they were the latest thing The picture of the Wright brothers on the wall in the 2nd picture was bought at Kitty Hawk itself.         Geoff Edited By Geoff Sleath on 09/03/2013 22:41:42

The shaped turtle deck. You can see the 5mm strip added to the top of the CNC cut fuselage side. The motor mounting showing the sidethrust angle built-in by angling the firewall. The spacer ring was made by cutting the larger diameter with a hole saw in my drill press. The centre hole is cut the same way but watch your fingers! I resorted to holding the balsa gently in a pair of slip joint pliers. Make sure the middle hole is big enough to get the motor through The wing parts being glued together using the fuselage jig as a clamp. As you can see, I use Titebond Geoff

First, the scheme for adding 5mm to the fuselage sides aft of the cockpit and fitting the triangular stock inside rather than on the edge seems to have worked out OK. I did that and glued the soft 10mm sheet on top and carved it to shape. Incidentally it necessitated a thorough sweeping of the floor afterwards to avoid treading dust/shavings out into the lounge (my workshop is an extension that opens off the lounge in our 19th century cottage) to avoid conflict with SWMBO . The angle just forward of the fin seems to be just about spot-on for the fin extension to mate up accurately. Second, I've fitted the motor. It's an XYH 3542 which is identiacl I think to the Turnigy and other 3542. I'm pretty sure XYH make them all and the rest are badged by the various companies. I set the firewall 38mm back on the right (starboard) side and 36mm back on the left (port) side to allow for the right thrust. This is too far back. The drawing shows a 10mm deep collar on the front of the original nose engine mount but I can only get about 5mm before it would foul the back of the spinner. So, if you're using a similar motor then the firewall should be nearer to the front by about 5mm (31 and 33mm from the front of the fuselage side). I'm not going to change mine. I'll just put up with a shallower spacer ring. Third, I'm glueing the wing sections together using my Fuselage jig as a sort of sash cramp. I think it's successful - I haven't removed them yet. As I'm having a removable wing I've cut the main (centre) part of the wing to 18" ie cut a 36" length of 100 x 10 mm balsa exactly in half. (How I wish everything was measured in metric units 1.5mm =1/16"; 3mm = 1/8" etc is only approximate and the little errors add up) The centre section will be 77mm and square (ie not profiled) so the wing will be in 3 pieces before being joined with the dihedral braces - see Phil Winks' drawings. So some progress today while SWMBO went out cycling and did about 120km in the drizzle. Geoff

You're probably right, Phil. I'm still not sure how I'll attach my wing but it will probably be something like you suggested. I'm not sure about the screws coming down from inside and being just long enough not to poke through the wing undersheet. It's a neat idea which adds to the scale effect but I wonder how easy it'll be to get them just long enough but not too short In the meantime I found this rather nice 3-view using my intended scheme. I like the black one but I fear my eyes probably won't. http://www.baronerosso.it/forum/attachments/contest-aerodimentoso-cimento-2011/153022d1275582189-ac-2011-n-24-embraer-short-tucano-tucano_3_view.jpg One of things I like about the Tucano's appearance is the elegant line over the canopy and down the turtle-back to the tail. In fact I drew a Tucano as an example when I reviewed ModelCad back in 1999 for another magazine - it remains my only review and they forgot to put my name on it. However I feel Nigel's design doesn't quite get enough rise to the bottom of canopy. The rear pilot (the instructor?) actually sits quite a bit higher than the pupil in front of him and the clear part at the back is a similar height to that at the front. The original design does show the cockpit floor cranked up near the front but not quite enough. I'm intending to increase the angle a bit better to represent the full-size. I also meant to add that I think I'll put some triangular stock along the bottom of the fuselage behind the wing so I can round it off as per this 3 view.  Shouldn't add much, if anything, to the weight as I'll be removing almost as much as I'm adding. Geoff Edited By Geoff Sleath on 09/03/2013 12:16:03 Edited By Geoff Sleath on 09/03/2013 12:17:13

I think it was Phil Winks who pointed out that the fuselage drawing was wrong behind the cockpit and the side was shown 10mm deeper than it should have been. I was tempted to cut my CNC cut sides down before commencing construction but decided to see how it was once the top had been drawn in. I though some of the extra would be lost in the curve. That has proved to be the case in part but there's still about 5mm too much. I've corrected this not by cutting some off but by adding 5mm. There's plenty of wood left to cut a 5mm strip long enough to glue to the sides. I've done that and intend to glue the triangular section to the inside without needing to flatted one corner as shown in the original design. There's a bit more wood but most of it will be carved away in the shaping process. I suspect Nigel adopted the structure so that he could make the sides from a standard piece of 4" (100mm) balsa sheet. The CNC cut sides are made from sheets stuck together to make them wider. Geoff

As regards the ply(?) doubler, is it round the wing seat? As I'm fitting a detachable wing I thought there might be some weakness there as the wing is no longer a part of the structure - at least it's not glued in. What thickness and depth is it and does it stretch all the way between F2 and F3? I think this is a ploy by the editorial team to get us all buying the magazine more frequently than heretofore Geoff

Using my SLEC fuselage jig I've been able to glue F2,F3 and the fin post all in one go and haven't had any splitting problems at F3 and I'm also using the CNC pack. What I have noticed (just!) is that when I experimentally draw in the sides to the curve of F2 it distorts at the top. F2 is very soft balsa and I've cut a huge hole in it. I think I'll add a 6x6 mm cross piece to give it some stiffness. I strongly recommend the building jig. It's like having another pair of hands - or even more! Usual disclaimer - nothing to do with SLEC except as a customer. Looks like I'll have to acquire a copy of the mag. Geoff

This my first attempt at adding photos to the forum so I hope it works OK A useful tool to aid building straight fuselages is the SLEC building jig and I've used it a lot but not for some time to a scratch build like this one. It's certainly easier to use if the formers interlock with the sides but, with patience, it works well with the Tucano. Just two views of the sides with F2, F3 and the fin post ready to epoxy in position. I used Grip 1 hour epoxy because it gives lots of time to adjust parts and is very strong once hardened. Takes a lot longer than an hour to cure, I find. It's probably not obvious but the gaps to fit the firewall are offset by 2mm to allow for the right thrust without using spacer washers which I find to be a bit fiddly. It's always an option to use washers to fine-tune the thrust if it becomes necessary. To aid alignment I also marked the centre of the formers. The firewall will be added later but before I draw in the side to the curve of the formers - a lot easier job using the jig. It will need some shaping at the top to fit the curve. I will be using the 3mm ply motor mount supplied in the CNC cut parts at the front but I've cut a large hole in it with a hole saw. Also cut a large hole in F2 for motor access. Geoff

It seems there are a few discrepancies between drawings and the CNC cut parts. My original drawing from 2003 shows the front of the fuselage side as being 68mm high, the CNC cut part is actually 67mm and it seems that Phil's drawing is 70mm, hence the dimensions of his firewall. It looks like I'll be trimming the firewall Phil designed by 2mm at the top and 1mm at the bottom. I don't think this will affect the motor thrust line too much. Something else to be aware of if you have the CNC pack. Former F2 is supplied as a solid piece. It needs to have hole(s) cut in it to allow access to the motor connections. I intend to cut a 30mm dia hole in the centre of mine. The need to cut access holes is written on the drawing but no holes are shown. Easy to forget and far easier to cut before glueing. Welcome aboard, Wolston Flyer Not sure you'll learn much except what not to do. This is a model I've been intending to build since 2003 so you can see how keen I am! Geoff     Edited By Geoff Sleath on 07/03/2013 19:52:24

Thanks, Phil. I can adjust as required. A lot easier to do it before glueing than afterwards. As I mention in my thread, my drawing is from 2003 and shows the side at 68mm! I guess paper dimensional stabilty and/or print accuracy may be to blame. I don't suppose a 1mm error in motor thrust line will be significant. I'll be delighted if the finished model is within a 1mm tolerance. Geoff