Great Thermal glider, But a real pig to get back from downwind, I had one for about 8 years until I lost it trying to come home from downwind, wouldnt penetrate and ended up stalling it half a field away and it crashed into a tree.. If I were to build one again, 2 things id change would be a more modern airfoil that has better LD for stretching the glide home, and build a conventional stab as opposed to the all moving tailplane, all moving is a disaster in the sense that the plane pitch hunts all the time in thermals, a fixed stab would stop it wanting to either dive or climb without stabilising itself..
Great video - thank you;. I just brought a new old stock one that has been built but never flown. I love what you did with the wheels on the side - any idea what size or where you got them from. Am sure I could find some to match somewhere. A beautiful scale mod- well done.
Hi. I just matched up the wheel size with the size of the sticker on the side of the plane. the wheels are pretty cheap. You can get them online or from any Hobby store. Made from plastic and rubber.
@@stephenhughcrisp Thanks so much for your advice, the Catalina looks so much better with them. I have a friend with mini lathe so fantastic. Can't wait for it to arrive. I spoke to a friend who's neighbour flew them in WW2 and he still has his original flying suit from WW2 - amazing stuff. Thanks again - I shall let you know how it goes.
Hello, I have the chance to buy this model of plane. I am a novice first time flyer and will be joining my local flying club. Do you think this plane would be suitable, will it fly using just rudder and elevator if the ailerons we fixed in place for a while until i can get my flying skills better.Many thanks
Hi Goldfinger. Is your model also the Graupner kit? If so, I would not recommend it to beginner flyers. This model is quite difficult to fly, and it will not work with only two channels, elevator and rudder. I would suggest go for a more simple model with a greater dihedral on the wings, which makes it much more stable.
@@stephenhughcrisp Hello, Thank you for the fast reply. Yes the plane is a Graupner, it's on ebay, 5 miles from where i live, it's already built looks brand new and has the motor, servos etc. It is £130. do you think it's worth me buying it to use in the future when i have learned the skills needed, and i get a trainer for now. Many thanks
She flys great and the winch... well a great design as well. Man I wish I was there with you. I have a Dynaflite BOT in the box so maybe I'll get it out and build it. Thanks for the inspiration.
@@stephenhughcrisp Yes I noticed that. You are way better than me, I am a failure at RC Flying. I fly my aeroplanes on Control Lines, I'm good at that.
Hi Michael. You ask a very deep question. I personally do not like the very extreme dihedral on gliders with only rudder and elevator. In addition, I like to have the ailerons as air brakes or flapperons because the Bird of time as you know, is such a good floater that it’s very difficult to control the landing. So, to answer your question - yes, I would definitely build the ailerons if I were to do it again.
Nice to see an old design flying again. A friend of mine built a Bird of Time back when the design 1st came out (must have around been 78 or 79). Being a bit of an aerodynamicist, I thought the wing plan form poor, so I built my own design using the bird of time section. The two gliders performed similarly with a fast & exceptionally flat glide. This due to the thin low camber section afforded by the so-called Philips entry. In this respect the models performed as standard aero algorithms would predict. They were great on windy day as you had the speed and range to go search for lift. While a floater would struggle to get very far at all upwind. But on a still day, the floaters were pretty well assured to get better duration, especially if lift was scarce. While the floaters had a steeper glide angle, they were so much slower with their high camber wings, that their sink rate was less then the much faster bird of time, but the bird of time had much a better range to find lift if it was about. Your model surprised me a bit as I expected to see more polyhedral, believing the design to be rudder elevator & spoilers. Then I noticed you did an aileron version & then it all made sense. Now I’m unsure if my memory of the originally design being without ailerons is correct or not. Do you know?
Thanks for a very interesting insight to the Bird of time. Please have a look at the actual build video of my Bird of time and you will see that I added the ailerons which were not standard. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-2SF64ZTiPWE.htmlsi=ybJpvBXpfDHBA7wL I removed quite a lot of dihedral due to the addition of the ailerons
Well then you are using the extended chord of the outboard wing panels for that features original purpose, ailerons. In the early days of gliders, several designs initially had poor aileron response. The simplest fix was to replace the ailerons with broader ones, which resulted in the plan form that the bird of time has. By the time the bird of time was designed, the real reason for that feature had been largely forgotten & popular perception became that it somehow improves flight efficiency. It doesn't though, it's actually a small detriment compared to the 2 most efficient planform solutions by Prof Lidwig Prandtl. For subsonic flight: If the design constraint is the wing span, then the most efficient planform is elliptical, but if the constraint is the wing root bending moment, then the wing can be lengthened out to the zero-lift point by adopting geometric twist & taper that together results in what has been termed a "bell shaped lift curve". This rotates the whole reaction vector towards the tip to produce some thrust in a more efficient way than tiplets do. This solves the problem of adverse yaw & was greatly exploited by the Horton Brothers towards & then after the end of & after WW2 in their flying wing designs. Prof Ludwig Prandtl’s paper on this based on his lifting line theory was published just prior to the war. It was a double-sided single sheet paper that the world apparently missed the significance of. I came across all this in the 80s & it has been taught by NASSA in more recent decades though. There are several RU-vid videos on such model aircraft if you care to search. I say this to show that many people are mistaken about the Bird of Time plan form, including the designer apparently. It is a rather cool looking & recognised design though. @@stephenhughcrisp
Hi Stephen. Congratulations for your video. I live in Chile on the other side of the world. I am working in the same construction project, Bird of Time KIT from Dynaflite. I have doubt about of diameter of shaft in the full fliying stab of de Dynaflite kit. I saw your solution in the video and I think is better taht the original. I need to know what diameter you use for these shaft made in carbon fiber rod or tube Thank you in advance for your comments
I built one about 30 years ago. It was the hardest to build kit I ever built. It had plans and instructions with very limited pictures. I would get so frustrated I would put it away for weeks. Finished about two years later. Best flying airplane I ever had….still have today and will never sell it.
Back in the early 80s the club built some winches using an old 50s Ford starter and a sewing machine peddle had some members make a frame from 1" steel square tubing another member turned the spools out of aluminum we used them for fun flights and contests I wouldn't be surprised if they are still in use they were bulletproof
when you say the motor came from an electric bicycle, could you give me the brand, or a direction to get one and a foot pedal to actuate it. Great video, I would like to build one, thank you - Steve
Hi. I bought the motor off AliExpress. Here are the search specs: 24V 350W electric motor electric bike motor conversion Kit MY1016 MOTOR engine for electric bicycle/scooter/tricycle. Email me on shcrisp@gmail.com if you don’t have any success. Stephen
You flew the Catalina so far away from the camera we couldn't tell what sort of airplane it was it could have been any airplane we wouldn't have known.
Excellent video! Shorter noses let an aircraft become more maneuverable. WW2 fights like the Zero short nose, very maneuverable. Ailerons on a thermal glider is an extra. The idea is to keep the wings flat to take advantage of maximum surface area for thermals. I have built 100” gliders like the Oly 99. Extra weight in the nose with lead is ok. When thermaling the nose will dip a bit at the aircraft rises. Consider making a solid tail instead of lengthening the nose. Just my experience. Beautiful airplane! Great work.
I’m a little late to the party on this video, however, I have to say this is one of the best glider/winching videos i’ve seen. Such a simple design using parts most rc pilots cane easily acquire. I’m not sure it would be less work than a bungee set up, but cool enough I think I have to build one. Thank you and take care.
Beautiful build of a classic bird (no pun intended!) Congrats on all of the design work and mods. Everything seems to be working well! It takes a brave man to cut the nose off after sanding and shaping! That area of the fuselage is highly stressed, so if you don't do it right, a hard landing could have you rebuilding the entire fuselage! Also takes a brave man to go back and rebuild the vertical stabilizer so that the ribs are more aesthetically pleasing, but then aesthetics is a major feature of the BOT. Well done!
Very nice work Stephen, though, I have to admit ... after the amazing work on the BOT and the precision winch design, I was almost let down by the simplicity of the return post. Wait! I spoke too soon. Your newly designed return pulley is more like I expected! <grin> Beautiful in flight. I expect you've had many hours of enjoyment out of that BOT. There's no chance you're and engineer, is there? <grin>
