Richard Harris Posted October 13, 2012 Share Posted October 13, 2012 All rotational flying machines have put to one side whilst I get this next project off my 'tick list'. Many years ago there was a free canard plan in a magazine called (I think) Candice, designed around a cox 049 engine. I built this model and converted it to electric with quite good results. At the back of my mind I always wanted to design my own, with the talk of club 20 and funfighters for the Mass Build this reignited the canard thought process off again. If it ended up being club 20 for our mass build it would have been this design and if it had been the latter then there was a Japanese WWII canard I wanted have a crack at. Unfortunately we never did get the chance to vote for these, but for me the damage was already done and I had made a start on the drawing board. UnCanny will be electric powered but I have this strange idea that if the prop is removed it would become slope happy, something I would like to have a go at. Basic sketches have been made and I have made a simple depron chuck glider to gauge the CG position and the size of the vertical surfaces etc. I have gone for smaller fins but added them to each horizontal surface. Being lazy I have opted for sheet lifting surfaces, I know it probably wont fly as well if it gets that far but this can always be improved upon at a later date. So a few photos of the 'chuckie UnCanny'. Rich Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted October 13, 2012 Share Posted October 13, 2012 Looks good Rich, how well does the chuckie version fly? I presume the powered version will be a pusher? Cheers Danny Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted October 13, 2012 Share Posted October 13, 2012 Should not be to difficult Rich after all the Wright brothers had a fair degree of success with canards and I recon you know just as much about bikes lol. Seriously it looks like an interesting project that should create some interest and keep the brain cells going .I would imagine c/g will be one of the first things to sort out. Tom. Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted October 13, 2012 Author Share Posted October 13, 2012 Danny, I have tried 'Chuckie' and it does glide but is unpredictable in yaw and can spiral out of the glide in either direction. So I will increase the vertical area a bit more and try again tomorrow. Tom, The best glides so far indicate a CG position around the LE edge of the rear wing, with the slightest of positive incidence bent into the fore plane. It will be all balsa and ply construction and a hand launch jobbie, I am thinking a highish KV motor to keep the diameter of the prop down but stick with a 2200mah 3 cell Lipo. I have an old Ken Stokes 'Mirus' , its the 25 sized version but I have shoe horned an OS 40 into it, this suffers from some kind of torque roll as its launched with the engine reving at full chat. It really has to be launched hard or throttle back a bit to get it away safely. Because it has a bigger engine than it was designed for I have always thought that this effect is a reaction from the larger prop? Hence me thinking smaller prop at this stage for my canard. Rich Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted October 13, 2012 Share Posted October 13, 2012 Rich. The loss of directional stability and tendency to flat spin or spiral seems to happen with this type of model as the speed bleeds off ,so c/g or trim forward a little to help keep the gliding speed up .Could be wrong but they would be my first thoughts.Aternativly if I remember correctly its side / fin area behind the cg that's important so maybe those canard fins are not helping ? Tom. Edited By Tom Wright 2 on 13/10/2012 23:02:15 Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted October 14, 2012 Share Posted October 14, 2012 I had a 'Lightning Dart' 70" flying wing with tip rudders and they were proportionaly about 3 times the size of yours. The mini-rudders on the foreplane look neat but I'm not sure about them as being in front of the centre of mass might they not exagerate any problems with yaw? Might be ok if they were gyro controlled? Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted October 14, 2012 Author Share Posted October 14, 2012 Tom, Bob, I have increased the area of the rear fins by about 20% and now it tracks straight, I may try removing the front ones but I think it adds a little character. A quick video test gliding out in the road this morning, yes I did have a few funny looks but not as many as when I am running up and down with a set of rotors in my hand! Better start cutting some balsa me thinks! Rich Edited By Richard Harris on 14/10/2012 12:41:09 Edited By Richard Harris on 14/10/2012 12:41:28 Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted October 14, 2012 Share Posted October 14, 2012 That's looking more promising! Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted October 15, 2012 Author Share Posted October 15, 2012 A laborious task but I have got most of my formers for the fuselage cut out. I have decided to make the fuselage in 2 halves , top and bottom. The bottom will be the load bearing structure and the top just cosmetic, this I think will make radio installation easier and battery changing as my son says 'pips'. The lower fuselage is made at the moment in 3 main fully jigging compartments, front and rear to mount the wing and canard and the middle for the battery. Probably thinking way to deep about this but the battery will be lower than the servos in hoping that I keep the CG/thrusline pretty close. Rubbish pictures but what I have so far. Rich Quote Link to comment Share on other sites More sharing options...
Tim Hooper Posted October 15, 2012 Share Posted October 15, 2012 Rich, Have the house prices in your street suffered as a result of your shennanigans? Looking good, Rich. Are those frontal fins vital? Seems to me they'd negate some of the input from the rear ones. tim Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted October 16, 2012 Author Share Posted October 16, 2012 Tim, I have to be honest about the frontal fins, I haven't got a clue! I just added them because I thought it would look good and didn't want it looking like every other candard. However It's no hardship to make them removable, I could compare them (of course that's if it ever gets into the air!) and leave them off if there is need. As for my shennanigans what you can't see is the balaclava I was wearing! the neighbours would never guess who it was Rich Quote Link to comment Share on other sites More sharing options...
Tom Wright 2 Posted October 16, 2012 Share Posted October 16, 2012 Posted by Richard Harris on 16/10/2012 14:23:11: As for my shennanigans what you can't see is the balaclava I was wearing! the neighbours would never guess who it was Rich As the wings were not rotating ,the neighbours might have thought it was a new boy on the block lol.. Tom. Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted October 16, 2012 Author Share Posted October 16, 2012 I like it Tom! A couple of hours work and all that freshly cut fire wood is starting to take shape, just clicked into place with a bit of fettling here and there and ran some of the pound shops finest Super Glue into the joints. Will bead up the joints that matter with no more nails wood glue. Top half needs to be sheeted next and the underside of the bottom blocked with soft 6mm thick balsa, then 'hell for leather' with the sanding block! Now how can I shoe horn a rotor mast on? Rich Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted October 17, 2012 Author Share Posted October 17, 2012 I have now sheeted the top half with some soft 3mm balsa sheet each side, easily achieved as I cheated and kept all the former angles all the same. Had to use somne thicker wood clamped to the base to keep things straight and true whilst I got all glue over my thmbs and fingers. These were sanded on the top to create a flat surface so as some soft 6mm balsa culd be stuck on top as a spine. It will need some more sanding but I will probably tack to the bottome part so they match, its ended up really light and quite rigid but it really serves no purpose other than for looks. After some elbow grease with my sanding block its starting to take shape, will make a mould to get a better fitting canopy. Rich Quote Link to comment Share on other sites More sharing options...
Tony Bennett Posted October 17, 2012 Share Posted October 17, 2012 you certainly build fast sir. nice design as well. Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted October 18, 2012 Author Share Posted October 18, 2012 Tony, Thankyou , I do like to build and get them done quickly as am known to loose interest easily! I made up the wings this afternoon (well glued them together last night with pva and left them to set overnight). A bit of razor planing and some work with my sanding block and I have managed to get an aerofoil out of the planks of balsa. It kind of looks like a plane now but still plenty t do like the nose block and flying controls. You can see that the top hatch is easily removed and the battery tray is well within reach, the servs will be simply sunk in to each lifting surface..job done! A few photos, would like to have done more but I cant sand inside so rained stop play. Rich Quote Link to comment Share on other sites More sharing options...
Tony Bennett Posted October 18, 2012 Share Posted October 18, 2012 fascinating. i best put one on my list of builds. Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted October 18, 2012 Share Posted October 18, 2012 Looks great Rich, I'll be following this with interest along with everyone else. I too wonder about those fins at the front though. Here's my thinking: If the model yaws away from straight then the fins at the back show their side to the oncoming air and push the model back into line because they are behind the C/G. But fins in front of the C/G showing their side to the airflow will cause the unwanted yaw to increase. They look further from the C/G than the ones at the back too so have a longer moment arm. Hopefully that's all complete rubbish and all will be fine - keep us posted Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted October 18, 2012 Author Share Posted October 18, 2012 Chris, Thanks for your explanation , it makes perfect sense. They may just cause more hastle than they are worth so I shall just stick with the rear fins (maybe increase their area a little more to be on the safe side?) Rich Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted October 19, 2012 Share Posted October 19, 2012 Hi , Richard Looks great , Which end is the motor going to go ? . Think of an arrow in flight , Large feathers at the back small blades at the front , <----<<< . I could be wrong , but if the motor is at the back then the front fins will have a large effect than if they where behind the prop , motor at the front , Sometimes its a case of suck it and see , Good luck , I will be keeping my eye one this one Quote Link to comment Share on other sites More sharing options...
riverlandgirl. Posted October 19, 2012 Share Posted October 19, 2012 Looking great, can't wait to see it flying! Good stuff. Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted October 19, 2012 Share Posted October 19, 2012 Now I am confused. If having forward fins makes the thing unstable, how have they got away with fins in front of the c of g on this: It clearly flies well Cheers Danny Edited By Chris Bott - Moderator on 19/10/2012 20:49:45 Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted October 19, 2012 Author Share Posted October 19, 2012 Thanks RLG, I hope it flies but like all of ur creations it has got two chances! Danny, For some reason I cannot see your picture? Rich Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted October 19, 2012 Share Posted October 19, 2012 Rich I breifly had the same problem, Dannys pic wasn't showing. Could you try a refresh of the page to see if it re appears as it has here? PS - just edited it to the correct shape. Edited By Chris Bott - Moderator on 19/10/2012 20:42:28 Quote Link to comment Share on other sites More sharing options...
Richard Harris Posted October 19, 2012 Author Share Posted October 19, 2012 Chris, I can't see any pictures? Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.