Thanks Jeff, yes I live near a big estuary and plenty of seaside. If I had a runway I'd have it all. Looking forward to your next heli video, they are always interesting.
The thing sure sounds awesome! I bet the 4-stroke sounds even better! This new project is sure adding lots of going really fast horizontally to the mix - good luck and have fun!
I can't wait, this should be awesome. Lots of reference material can also be had from the Mudskipper in West Australia, which also runs a Jabiru engine, as I'm sure you know.
Lots of Honda cars engine as a reverse rotation, when you open the hood of the FWD the engine is on the other side ! This boat with the triangle wing and your good to go fly and higher than the other thing 😮
Hadn't thought about cars having engines in the opposite way around. 👍 I've got the wing for the fib and it could of course just be flown as it is. Would have to get a microlight licence though which I wouldn't mind doing at some point.
Hi, I hope your project goes well! A suggestion however, as the type of amphibious microlight is rare, try and keep the frame/ hull etc. as standard as possible. If you decide to return it to airworthy (better resale value) you won’t get caught out. Use bombardier oil as Rotax two stroke have a tendency to nip up if run lean or very hot. Onward and upwards, all the best.
Great advice!!! The AM FIB will be kept 100% original and I intend to return it to airworthiness at the end. 👍 Thanks for the oil tip and CHT vs EGT, I'll take a closer look at the gauge and see.
Hi John, yes I could and it would solve the engine issues. I can see the value in these engines designed for aircraft. It's a lot of work to make ground dwelling engines reliable and light enough for aircraft. I like them. David Mitchell 😆
@@Ben-Dixey Just read the owners manual for the 582, it states; "This engine, by its design, is subject to sudden stoppage. Engine stoppage can result in crash landings, forced landings or no power landings. Such crash landings can lead to serious bodily injury or death."
Nice video!! The Ekranoplan idea is cool. Maybe use the Rotax for another build, say a gyro? No shame in getting plans and building from them. Cant wait for your next video mate.
Yes the Rotax will no doubt be useful to own. I didn't buy an aircraft engine for the helicopter because of cost but I can see the value in them now. They have lots of modifications to make them reliable as well as being light weight. It would be perfect for a gyro.
You're right Peter, it's not going to be as light as it could be using the RIB. It just seemed like an easier solution as we know the RIB is designed for the speed and durability.
Neat project, looking forward to the updates, one thing that doesn't sit right with me is having the wings closer to the water seems more dangerous, but this isn't my area of knowledge
Yes, that's true. What James greenberger did with his mudskipper is add small floats to the ends of the wings. They have been well tested and he seems happy with the design. I will be wanting to do the same.
go tractor config with par thrust . put the engine down low and out of air stream less drag . run a long drive shaft with 2 sets of universal joints to the prop out front .. front wheel drive car steering knuckle and cv joint for par thrust and thrust bearing .. canard wing behind prop for pitch
@@Ben-Dixey water is very sticky and draggy its better to haveas much lift as possible at as lowest ground speed as possible to get off as soon as u can cause water is very bumpy and hard on airframes and such
Glad it's of interest DK, the jabiru is 80-85hp. Quite derated for its size and the slow running is much preferred over the high rpm 2 stroke. Hopefully a good choice.
Ben, that ElectricAviation_AnalysisTool_2023-05-14 spreadsheet I sent you has a "Fixed wing" tab for you to play with various wing planforms and see what power vs speed looks like. Of course it was designed for aircraft flight, so I need to scale induced power vs height. Hyperbolic tangent reasonable starting point: induced_power_scale = tanh( const * height / wingspan). Use rectangular planform wing so that tips never get close to stalling. Will you be using Aquaplane K42 general planform with elevator?
A quick look finds a suitable ground effect on induced drag model [1] as function of height h over wingspan b. Cdi' = (1 - (1 - 0.66 * h/b)/(1.05 + 3.7 * h/b)) * Cdi for h/b < 0.5 1. REID, E.G., 1927, A full scale investigation of ground effect, NTRS So, for spreadsheet approximation a fit might be Cdi' = Cdi * (tanh( 1.37 * h / b) )^0.5 , for all h/b I'll have a think...
@@martingarrish4082 That's really helpful Martin! I will play around with the spreadsheet and see what I can learn from it. Will get back to you. Thank you!
@@Ben-Dixey , I need to start developing that tool to help you and the Electric Aviation channel. Idea is to help designers to play around with concepts - Excel makes sense for that. Early days. In the mean time wikipedia not bad on the basics. en.wikipedia.org/wiki/Lift-induced_drag As for books, you could get Anderson, "Fundamentals of Aerodynamics". It's the sort of book you dip into from time to time. Same author, "Introduction to Flight" looks pretty good too.
@@Ben-Dixey , a little Sunday coffee time digging reveals that Anderson, "Introduction to Flight", recommends McCormick, B.W. "Aerodynamics Aeronautics and Flight Mech" for ground effect correction to induced drag: Cdi' = Cdi * 16 * (h/b)^2 / (1 + 16 * (h/b)^2) , where Cdi = Cl^2 / (Pi * AR * e) ref wikipedia page above. Slightly different to that Reid paper. I could update the spreadsheet calculator, but not happy with the variation in published fits. So, I might have to pull out the stops on this and update my Prandtl lifting line code to include ground effect. I need to do the same for rotary wings at some point (idea was for tool to facilitate e-VTOL & e-STOL design).
@@martingarrish4082 Thanks for for this Martin, I've made a note of this equation, great stuff. I've been working out the CL for James's mudskipper. For the helicopter project I never attempted any lift calculations and so even the basic lift equation is unfamiliar, until a couple days ago. I'm starting at the beginning and have a lot of catching up to do before I can engage with you on the subject. James has provided me with some data and I think these figures are reasonably accurate. Takeoff weight 490kg wing area 18m^2 take off speed 16.6m/s Air density 1.225 kg/m^3 Using these figures and the equation CL=L/(1/2 * pv^2 * a) I get a lift coefficient of 1.66 The angle of attack of the wing is 5.5 degrees Is the CL figure I have come up with correct? I need to understand the basics before I can use your spread sheet. I haven't done any drag calculations yet.
Great to seeing you back here Ben . I am not sure are you willing to use these engines in fix wing or rottory wing aircraft ? Fixed wing is certainly less complicated then what you already have achieved. Greetings
Thank you! 😊 engines are for a fixed wing, ground effect boat. I like these aircraft engines and either would be good in a helicopter or other hovering machine in the future. Good purchases I think. They are the right things for the job they just cost more than other engines. Worth the money in my opinion.
@@Ben-Dixey ohh fair enough, and when we talk about amount of time we need to spend in the project, I assure you no matter how longer you take to think , research,make plans ,build things ,test them get failure then improve it just so worthy comparing the other same age people wasting that time in pubs over drinkimg or watching bullshit reels or bickering fellows. I think we all enjoy the time you spend in those projects, challenges are fun to accept, And trying to create new design build new thing your own is fully worthy no matter how long you spend your time it. Full support to your new project brother. Greetings
Completely agree. I see videos on TH-cam of people smashing stuff up for entertainment, like Mr Beast or whistlin diesel, they get massive audiences watching them do this stuff that anyone can do. I don't understand why so many people want to watch things getting broken rather than things being created or fixed, I don't understand it.
@@Ben-Dixey yeah me too wonder how people just for sake of views destroy the stuffs but environment too. I assume Viewers and Followers are most of them ,those don't even have well understanding with machines and science. But time spand in creation is never wasted no matter how long it takes because other who don't dare to take that challenges simultaneously pathetically wasting their times around creating nothing.
@@Ben-Dixey They Can push if they're totally enclosed like a choke cable but for any significant load the inner cable would need to be solid, at least where they exit the outer cable. With high loads like control surfaces the friction generated inside the tube under load (while pushing) and the backlash caused by the clearance between the inner and outer would make a single push-pull cable a poor choice. Even car throttle cables only pull and have a return spring. I can't claim to know every cable setup but my experience where cables are used in light aircraft is that they generally have open cables and pulleys with either 2 cables direct to the control surface or to an intermediate bellcrank with a pushrod from there to the control surface. Try holding the ailerons or elevator still while moving the stick. That might show you what's going on. Hopefully it's solid both ways !
Another thought, another thread: what aerofoil section is Kester Hayes using in the Aquaplane K42? It looks like a NACA 4-digit series. These are good all round aerofoil sections, albeit slightly draggy, so I wondered if you were considering the laminar flow NACA 5-digit series. Or maybe the GOE sections fitted to wooden wing gliders or FX sections fitted to later composite designs. Abbott & Doenhoff, "Theory of Wing Sections Including a Summary of Airfoil Data", still in print to give you some ideas - I have a pdf if you sets up googley drive or similar...
I will check with him but I think he said the wings were from a thruster microlight. Can't find the airfoil section after a quick google. I would really like to use the hoverwing, Sail cloth type wings because they are so simple but I need to know what the difference in lift is from the hoverwing type to a proper airfoil. I suspect the leading edge and the topside airfoil shape is going to be the most important for lift. I'm just waiting for Kester to come back to me on takeoff speed. I will ask him about your aileron/elevator mixing just trying not to bombard him too much with questions.
I am no plane engineer. But i am a car mechanic. If you are planning to use this engine, i will sujest to replace that water radiator. It has seen better days and might not provide suficient cooling anymore, do to much of the cooling fins has falen of. This could be a pre warning of a soon to leak radiator as well. Just a freandly warning what can happen when this engine is in use for longer time.
Completely agree, it needs replacing, I've got the Valeo number and I can get the same one for £800. It's from on old Italian car but I'm sure I can find something that requires the least modifications. You can buy the correct twin rotax radiators for £150, just have to modify the mountings and hoses.
@@Ben-Dixey Good. The last thing you want up in the air, is a hot running engine and leaks, that can lead engine failure. But that should not be a problem as you seems to all ready want ot replace it.
G'day, Very interesting. Rotaxes are very good and very reliable, if maintained and operated Intelligently and Dilligently. I was Launch Controller for Aerotowing Adventures Australia, while a mate Aerotow-launched 500 Rogallos between 1992 & 1997...; he had bought the Prototype Bailey,-Moyes Dragonfly - an ANO 95.10 Ultralight designed for Aerotowing, when it was 100 hours old (flight time). Low speed, high power, on a hot day, climbing out at 25mph & 500 ft/min pulling a big heavy Hang Glider pilot was causing overheating; but an Automotive Windscreen Washer Bottle's Electric Pump feeding two perforated thin Plastic Tubes fixed an inch forward of the Radiator, with a Cold Water Reservoir fixed that... A couple if seconds' squirting Water on the Front if the Radiator vastly increased the Adiabatic Lapse Rate, and sucked all the heat out of the Coolabt in the Radiator. Rinse & repeat. A big part of our Ritual was Carefully mixing the Penrite "Green Slime" HPR 2-stroke Oil inyo the Fuel. We were so obsessive that after 500 hours when old mate pulled the Exgaust off to look indide, the Pistons still had the Circumfrential Grinding-Grooves in the Aluminium Sidewalls, The Piston Skirts had never touched the Cylinder Liners... So, be fastidious, and the Rotax will serve you well. I wonder if that Inflatable Rubber Ducky will have Sufficient hydrodynamic stability in Pitch, particularly in choppy water..., to work out in an Ekranoplane ; it's pretty short, and wide. Water is a LOT more Energetic than is Air at 30 or 50 mph, Per cubic Foot of Contact Area... Will your Horizontal Stabiliser and Elevator be Large enough and given a Sufficiently long Moment-Arm, As to be able to debate the point, when it comes to Argueing with a Wave which is smacking the Bow into a Pitch-up ; And your Elevator is attempting to keep the Nose down To avoid Overpitching, climbing out of Ground Effect, then Stalling..., & either Diving or Spinning back down...? The majority of the Ground Effect Vehicles, of which I'm aware at least, seem to have a Hull with a wetted Length that's rather longer than the Wingspan... I've assumed the noticable long thin hull was both to reduce Hydrodynamic Drag, and for better damping of Pitch oscillation when Waterborne...(?). It'll be an interesting project. Stay safe. ;-p Ciao !
Thanks for the very intelligent comment. I don't know the answer to the question of pitch oscillation of a short hull and problems with the extra lift being generated by sudden increases in the angle of attack. Where I'm planning to operate is a large estuary. As this craft will only be operating in very light winds the water will be calm and little chop is expected. The estuary gets choppier the further out to see you go so testing can be done progressively, I think. The elevator area I've copied from two other wing in ground effect craft. James Greenberger and Kester Haynes. Here is kester in choppy water bouncing off the waves trying to get airborne. His floats are longer than my Rib so you have a point. th-cam.com/video/Fj2XR17qg3Q/w-d-xo.htmlsi=maJwVESQoEfkbsRt I'm in regular contact with James and kester so will ask them about the shorter hull. 👍 Thanks for the info on the Rotax.
@@Ben-Dixey Thanks, No worries... Cool, as long as you're onto the Hull-Length issue and are keeping an eye on the Pitch thing. Smooth Water will help a lot, too. I wasn't expecting the link to go to Bear Grylls' Channel..., I usually think of him Rock-Climbing in the Jungle looking for a Snake, to eat it Raw (!). Kester Haynes certainly was bouncing around from Crest to Crest before becoming airborne, but with those Floats their length did seem to damp the pitching..., apparently because to lift their noses the sterns have to be submerged, and being hollow (or foam-filled ?) even the trailing Edges are buoyant..., a long way back. I'm trying to figure out whether it will be a real issue or an imaginary one, and if real - whether a small Float (maybe a 2 or 3 litre Plastic Coke-Bottle, base-forward for streamlining..., fixed under the Tail ; would help with damping any Tail-down moment ,- or whether the added Hydrodynamic Drag when the Float gets wet would hinder acceleration, right when any such extra Drag would be most unhelpful ?). I reckon you'll have more data when you've had it on the Water..., it might not be any problem at all...; but it can't hurt to think about it in advance..., in case it causes hassles. Keep on keeping on. Stay safe. ;-p Ciao!
@@WarblesOnALot Point taken, Kester's floats are 4m long, my Rib is 3.5m long so there is a difference. It will be interesting to find out. As with the helicopter I will report my findings. I sort of have loose plans to build aluminium catamaran floats in the future, will see how things develop. If you Google kester Haynes k42 aqua plane you will find his website where there is a video of the first flight. Back then he didn't have the aircraft floats instead he used a Zapcat rib. It's an exciting video as he didn't have a pilots licence back then.
@@Ben-Dixey Cool ! I suspect the long Catamaran made of Aircraft type Floats might be a good way to go. I'm a bit of an Internet Luddite, actually, never had a Computer, my daughter created my Channel & bookmarked it onto my prepaid Mobile Phone...; and I keep it Cookie & Virus free by not following Links away from YT, nor "surfing the Net" - rather, I merely "play on YT". So I'll take your word about his first flight. I live atop the Great Dividing Range, and there's no big flat Water within about a hundred miles, otherwise I would be very tempted to have a go at building something like the German Trimaran GEV which I saw on TV as a kid...; and up here it's the full Levitation Thing and climbing up high enough to be able to cope with Engine Failure by Gliding to a Clearing - or stay on the Ground, kind of thing. Anyway, stay safe. ;-p Ciao !
I would like to hear any ideas you have Martin. I haven't posted on any forum. Are you a part of any forums that you think would be particularly suited ?
@@Ben-Dixey , not a forum but I was involved in an aerobatic electric aircraft project at Cranfield that didn't go anywhere at the time (we were all busy). Biggest problem with operating in ground effect is the longitudinal transient response time. You can see it in the K42 videos: pilot (Kester one assumes) puts in an input to climb, elevator causes the fuselage to change angle, then the wing eventually climbs. So there is a lag in the response that increases pilot workload. What you wants is a flapevatoron system. This is a mixing of control inputs to flap, aileron, and elevator. For longitudinal speed stability you need to put mass centre slightly ahead of main wing so that horizontal tailplane is having to counteract. It is referred to as longitudinal dihedral in the text books. If you connect flap to elevator then you get the desired longitudinal control and speed stability but without the response lag. You also have to mix aileron and flaps, hence flapevatoron system. Only issue is need to put a trim system in to counteract the control force, but this is done all of the time in aircraft. Your project is the perfect showcase to demonstrate the viability of this system...
Interesting, so the ailerons would flap down to increase the lift of the wing during the up elevator ? Regarding the location of mass I believe this needs to be located between the 25% chord and 40% chord of the wing. I think in ground effect the centre of pressure starts at 40% and moves forward as height increases. Somewhere between the two would be the compromise ?
@@Ben-Dixey , yeah that's the mechanism. Flaperons are already used on high performance gliders, so nothing new there. The new bit is combining flap and elevator. You tune the flap to elevator ratio so that the main_wing and horizontal_stabiliser always produces zero moment about the mass centre, so only a lift force. Then it's a question of optimising for least drag over the flight speed range, and ensuring docile trailing edge (and flap) stall characteristics. For a simple wing the centre of lift will typically be between 25% and 40% chord, depending on camber and AoA. For an aircraft in flight you want the mass centre to be a little forward of the main wing so that as the aircraft speeds up there is a pitch up tendency, and as the aircraft slows down there is a pitch down tendency. This reduces pilot workload, but there is a trivial trim drag penalty from the elevator pushing down against main wing. In practice the elevator is affected by downwash from main wing which will reduce trim drag. (The argument for Canards is that they avoid this trim drag, but you get the canard tip vortices affecting main wing which normally makes drag worse.) For an aircraft that is designed to fly continuously in a fully held off landing then speed stability will be less of an issue. However you want the aircraft to reject gusts, so to my mind having mass centre ahead of wing still sounds like a wise idea. I can use that speadsheet to generate some charts when you have an idea about masses and wing planform. Whole point of the exercise is to reduce pilot workload, hence fatigue, hence mistakes. But, I would definitely bounce this stuff off Kester Haynes as theory guided by experiment is always the best solution. His experience might be different from my short duration extended glider landings down airfields. It may be that he recommends putting mass centre on wing centre of pressure, in which case the flapevatoron system would be all flap and no elevator...
Great help Martin. I'm so glad you are willing to chip in with ideas and thoughts. I'm writing it all down so that I can eventually make informed design decisions. It helps when I've got two flying examples and two people willing to share the details with me. I can compare the theory with actual data. I'll speak with Kester about your flapevateron idea and find out where his centre of mass is located. 👍
The blue head 582 is the most powerful 582 Rotax built. When you say fly are you talking about in ground effects or to actually fly? If actually flying is the idea the you will need to change the prop. P factor will be way to much with an airboat prop. Look up flying hovercraft. I built a house here on a creek we flew at in ground effects for years. No need for ailerons just basic tail and most use blue head 582's. Any way good luck.
Hi, thanks for the info. Yes I want to fly in ground effect only. I'm doing some training in a fixed wing microlight and it's fun but low to the ground I think is where I'd rather be. The prop is from the Polaris fib and I do have the flex wing. When I'm finished having fun in ground effect I might get it back up together as the fib configuration. What machine did you fly in ground effect ?
The first one I built was a Scat 2 Hovercraft 10ft long I converted to a Hirth 625cc 65hp Fan cooled it's what you need on your helicopter with 2.6 reduction with 9 blade ducted fan. I put 2 aluminum cross tubes on it with 5 bows on each side with rip stop fabric just on top. Added the elevator on the DF shroud so I just had 3 controls throttle , elevator and rudder. After that found a Neoteric with larger 9 blade fan duct 300hp Kawasaki with super charger off Jetski. Set it up the exact same way but was so much nicer. Could seat 4 and fly 3-4ft off the water at about half throttle. I built a house in the country 30 years ago with my wife two daughters on 100 acres looks like a state park with a really nice creek running through it right to the Mississippi river 10 miles down stream. I've loved designing and building rotorcraft, hovercraft, airboats since I was little. Just about to finish a machine that works like a autogyro buts electric with several fail safes built in. Will fly like a air ATV around the farm. Plan to start posting next week. I'll video some pics of machines I've built over the years. I worked with NASA on the Mar rover project that flew on Mars. I designed and build what Langley ask for but they didn't choose the machine ended up going with another companies design in the end.
ChecK out the link below for Jabiru info, Be careful not too over cook the cylinder heads !!!!!!!!! www.lightaircraftassociation.co.uk/engineering/TADs/E03%20JABIRU.pdf
Hopefully they still make these amphibious microlights. I am looking to buy one for my own project. :)
Awesome Ben - great to see you got your mojo back! Mad as a march hare! Lovely!!
Thanks Mr HeliShed, I think we both have just the right amount of Madness. 😉
@@Ben-Dixey yes pal! Yes!!
Here we go again!.
Popcorn is ready !!! Good luck and have fun with your build!
Thanks for the encouragement. 😊 It should be a lot of fun.
New project gets a thumbs up from me - looking forward to see the build - good luck.
Thank you 😊
Great to see you back, great project, great sense of humour 😂🏴
thank you 😊😊
Well let this new chapter begin...hope you have huge rivers and lakes around you 😅. Great video with some cool comedy in it 🎉
Thanks Jeff, yes I live near a big estuary and plenty of seaside. If I had a runway I'd have it all. Looking forward to your next heli video, they are always interesting.
The thing sure sounds awesome! I bet the 4-stroke sounds even better!
This new project is sure adding lots of going really fast horizontally to the mix - good luck and have fun!
Looking forward to hearing the jabiru run and I like the sound of it too! 👍
This homebuilt craft has nothing to do with ground-effect. This is no W.I.G
This is going to be fun, can't wait, great to see you back👍🇬🇧✌️
Cheers for the support 😊 yes I think it's going to be very fun. Hopefully some interesting videos to come.
Nice video mate. Glad you have the ground effect bug now!!
Thanks James, well and truly got the bug for this project, seeing your flying videos makes me want it even more. 😊
I can't wait, this should be awesome. Lots of reference material can also be had from the Mudskipper in West Australia, which also runs a Jabiru engine, as I'm sure you know.
Thanks, yes the mudskipper is awesome and James has offered advice. I'll be asking questions for sure, what he has achieved is amazing.
looking forward to see you building it. Great video!
👍😀
Good evening Ben, is it new project is it fly boat. Cool👍👍
👍
Lots of Honda cars engine as a reverse rotation, when you open the hood of the FWD the engine is on the other side !
This boat with the triangle wing and your good to go fly and higher than the other thing 😮
Hadn't thought about cars having engines in the opposite way around. 👍 I've got the wing for the fib and it could of course just be flown as it is. Would have to get a microlight licence though which I wouldn't mind doing at some point.
now this is something I can get into
Glad it's of interest 👍
Such a cool project! Equally entertaining and educational, keep up the good work mate, and best of luck! :)
Thank you, I'm looking forward to it!
Hi, I hope your project goes well! A suggestion however, as the type of amphibious microlight is rare, try and keep the frame/ hull etc. as standard as possible. If you decide to return it to airworthy (better resale value) you won’t get caught out. Use bombardier oil as Rotax two stroke have a tendency to nip up if run lean or very hot. Onward and upwards, all the best.
Great advice!!! The AM FIB will be kept 100% original and I intend to return it to airworthiness at the end. 👍
Thanks for the oil tip and CHT vs EGT, I'll take a closer look at the gauge and see.
That's fricken cool. I can't wait to see you progress.
👌👍
Now you can use the Rotax for your little helicopter. water cooling for a helicopter, air cooling for a boat, the irony. Best of luck David Mitchell
Hi John, yes I could and it would solve the engine issues. I can see the value in these engines designed for aircraft. It's a lot of work to make ground dwelling engines reliable and light enough for aircraft. I like them. David Mitchell 😆
@@Ben-Dixey Just read the owners manual for the 582, it states; "This engine, by its design, is subject to sudden stoppage. Engine stoppage can result in crash landings, forced landings or no power
landings. Such crash landings can lead to serious bodily injury or
death."
Turbine it is then ! 😉
Nice video!! The Ekranoplan idea is cool. Maybe use the Rotax for another build, say a gyro? No shame in getting plans and building from them. Cant wait for your next video mate.
Yes the Rotax will no doubt be useful to own. I didn't buy an aircraft engine for the helicopter because of cost but I can see the value in them now. They have lots of modifications to make them reliable as well as being light weight. It would be perfect for a gyro.
Thing is BEN they have microlight trkes that have attachable floats, you might end up with a heavy craft.
You're right Peter, it's not going to be as light as it could be using the RIB. It just seemed like an easier solution as we know the RIB is designed for the speed and durability.
Neat project, looking forward to the updates, one thing that doesn't sit right with me is having the wings closer to the water seems more dangerous, but this isn't my area of knowledge
Yes, that's true. What James greenberger did with his mudskipper is add small floats to the ends of the wings. They have been well tested and he seems happy with the design. I will be wanting to do the same.
go tractor config with par thrust . put the engine down low and out of air stream less drag . run a long drive shaft with 2 sets of universal joints to the prop out front .. front wheel drive car steering knuckle and cv joint for par thrust and thrust bearing .. canard wing behind prop for pitch
It's certainly an option I've considered, probably the best configuration, just more complex.
@@Ben-Dixey water is very sticky and draggy its better to haveas much lift as possible at as lowest ground speed as possible to get off as soon as u can cause water is very bumpy and hard on airframes and such
Would you need the reverse delta wing for that configuration? To make the most of the par thrust?
@@Ben-Dixey no . just big end caps / plates .. with a pinch of floatation in them like this
th-cam.com/video/gyLwK7Akx2I/w-d-xo.html
Good job👍👍👍..
Awesome video super excited to watch this being created! 2000 rpm is slow for that motor must sound cool how many horsepower?
Glad it's of interest DK, the jabiru is 80-85hp. Quite derated for its size and the slow running is much preferred over the high rpm 2 stroke. Hopefully a good choice.
Ben, that ElectricAviation_AnalysisTool_2023-05-14 spreadsheet I sent you has a "Fixed wing" tab for you to play with various wing planforms and see what power vs speed looks like. Of course it was designed for aircraft flight, so I need to scale induced power vs height. Hyperbolic tangent reasonable starting point:
induced_power_scale = tanh( const * height / wingspan).
Use rectangular planform wing so that tips never get close to stalling. Will you be using Aquaplane K42 general planform with elevator?
A quick look finds a suitable ground effect on induced drag model [1] as function of height h over wingspan b.
Cdi' = (1 - (1 - 0.66 * h/b)/(1.05 + 3.7 * h/b)) * Cdi for h/b < 0.5
1. REID, E.G., 1927, A full scale investigation of ground effect, NTRS
So, for spreadsheet approximation a fit might be
Cdi' = Cdi * (tanh( 1.37 * h / b) )^0.5 , for all h/b
I'll have a think...
@@martingarrish4082 That's really helpful Martin! I will play around with the spreadsheet and see what I can learn from it. Will get back to you. Thank you!
@@Ben-Dixey , I need to start developing that tool to help you and the Electric Aviation channel. Idea is to help designers to play around with concepts - Excel makes sense for that. Early days. In the mean time wikipedia not bad on the basics.
en.wikipedia.org/wiki/Lift-induced_drag
As for books, you could get Anderson, "Fundamentals of Aerodynamics". It's the sort of book you dip into from time to time. Same author, "Introduction to Flight" looks pretty good too.
@@Ben-Dixey , a little Sunday coffee time digging reveals that Anderson, "Introduction to Flight", recommends McCormick, B.W. "Aerodynamics Aeronautics and Flight Mech" for ground effect correction to induced drag:
Cdi' = Cdi * 16 * (h/b)^2 / (1 + 16 * (h/b)^2) , where Cdi = Cl^2 / (Pi * AR * e) ref wikipedia page above.
Slightly different to that Reid paper. I could update the spreadsheet calculator, but not happy with the variation in published fits.
So, I might have to pull out the stops on this and update my Prandtl lifting line code to include ground effect.
I need to do the same for rotary wings at some point (idea was for tool to facilitate e-VTOL & e-STOL design).
@@martingarrish4082 Thanks for for this Martin, I've made a note of this equation, great stuff.
I've been working out the CL for James's mudskipper. For the helicopter project I never attempted any lift calculations and so even the basic lift equation is unfamiliar, until a couple days ago. I'm starting at the beginning and have a lot of catching up to do before I can engage with you on the subject.
James has provided me with some data and I think these figures are reasonably accurate.
Takeoff weight 490kg
wing area 18m^2
take off speed 16.6m/s
Air density 1.225 kg/m^3
Using these figures and the equation
CL=L/(1/2 * pv^2 * a)
I get a lift coefficient of 1.66
The angle of attack of the wing is 5.5 degrees
Is the CL figure I have come up with correct?
I need to understand the basics before I can use your spread sheet. I haven't done any drag calculations yet.
Can't wait,thank you
😊👍
Great to seeing you back here Ben .
I am not sure are you willing to use these engines in fix wing or rottory wing aircraft ?
Fixed wing is certainly less complicated then what you already have achieved.
Greetings
Thank you! 😊 engines are for a fixed wing, ground effect boat. I like these aircraft engines and either would be good in a helicopter or other hovering machine in the future. Good purchases I think. They are the right things for the job they just cost more than other engines. Worth the money in my opinion.
@@Ben-Dixey ohh fair enough, and when we talk about amount of time we need to spend in the project, I assure you no matter how longer you take to think , research,make plans ,build things ,test them get failure then improve it just so worthy comparing the other same age people wasting that time in pubs over drinkimg or watching bullshit reels or bickering fellows.
I think we all enjoy the time you spend in those projects, challenges are fun to accept,
And trying to create new design build new thing your own is fully worthy no matter how long you spend your time it.
Full support to your new project brother.
Greetings
Completely agree. I see videos on TH-cam of people smashing stuff up for entertainment, like Mr Beast or whistlin diesel, they get massive audiences watching them do this stuff that anyone can do. I don't understand why so many people want to watch things getting broken rather than things being created or fixed, I don't understand it.
@@Ben-Dixey yeah me too wonder how people just for sake of views destroy the stuffs but environment too.
I assume Viewers and Followers are most of them ,those don't even have well understanding with machines and science.
But time spand in creation is never wasted no matter how long it takes because other who don't dare to take that challenges simultaneously pathetically wasting their times around creating nothing.
At the risk of being the pedant in the room, those control cables are pull-pull. They don't push.
The rudder controls can't push but it looks like the elevator and ailerons have to push?
@@Ben-Dixey They Can push if they're totally enclosed like a choke cable but for any significant load the inner cable would need to be solid, at least where they exit the outer cable. With high loads like control surfaces the friction generated inside the tube under load (while pushing) and the backlash caused by the clearance between the inner and outer would make a single push-pull cable a poor choice. Even car throttle cables only pull and have a return spring.
I can't claim to know every cable setup but my experience where cables are used in light aircraft is that they generally have open cables and pulleys with either 2 cables direct to the control surface or to an intermediate bellcrank with a pushrod from there to the control surface.
Try holding the ailerons or elevator still while moving the stick. That might show you what's going on. Hopefully it's solid both ways !
@@Andrew_Fernie Understood, thank you! 👍👍 Backlash is something I would like to avoid when building mine.
Another thought, another thread: what aerofoil section is Kester Hayes using in the Aquaplane K42? It looks like a NACA 4-digit series. These are good all round aerofoil sections, albeit slightly draggy, so I wondered if you were considering the laminar flow NACA 5-digit series. Or maybe the GOE sections fitted to wooden wing gliders or FX sections fitted to later composite designs. Abbott & Doenhoff, "Theory of Wing Sections Including a Summary of Airfoil Data", still in print to give you some ideas - I have a pdf if you sets up googley drive or similar...
I will check with him but I think he said the wings were from a thruster microlight. Can't find the airfoil section after a quick google.
I would really like to use the hoverwing, Sail cloth type wings because they are so simple but I need to know what the difference in lift is from the hoverwing type to a proper airfoil. I suspect the leading edge and the topside airfoil shape is going to be the most important for lift. I'm just waiting for Kester to come back to me on takeoff speed. I will ask him about your aileron/elevator mixing just trying not to bombard him too much with questions.
Build an ultralight aircraft
It will be very exciting
👍
I am no plane engineer. But i am a car mechanic. If you are planning to use this engine, i will sujest to replace that water radiator. It has seen better days and might not provide suficient cooling anymore, do to much of the cooling fins has falen of. This could be a pre warning of a soon to leak radiator as well. Just a freandly warning what can happen when this engine is in use for longer time.
Completely agree, it needs replacing, I've got the Valeo number and I can get the same one for £800. It's from on old Italian car but I'm sure I can find something that requires the least modifications. You can buy the correct twin rotax radiators for
£150, just have to modify the mountings and hoses.
@@Ben-Dixey Good. The last thing you want up in the air, is a hot running engine and leaks, that can lead engine failure. But that should not be a problem as you seems to all ready want ot replace it.
G'day,
Very interesting.
Rotaxes are very good and very reliable, if maintained and operated
Intelligently and
Dilligently.
I was Launch Controller for
Aerotowing Adventures Australia, while a mate Aerotow-launched 500 Rogallos between 1992 & 1997...; he had bought the
Prototype Bailey,-Moyes Dragonfly - an ANO 95.10 Ultralight designed for Aerotowing, when it was 100 hours old (flight time).
Low speed, high power, on a hot day, climbing out at 25mph & 500 ft/min pulling a big heavy Hang Glider pilot was causing overheating; but an Automotive Windscreen Washer Bottle's Electric Pump feeding two perforated thin Plastic Tubes fixed an inch forward of the Radiator, with a Cold Water Reservoir fixed that...
A couple if seconds' squirting Water on the Front if the Radiator vastly increased the Adiabatic Lapse Rate, and sucked all the heat out of the Coolabt in the Radiator.
Rinse & repeat.
A big part of our Ritual was
Carefully mixing the
Penrite "Green Slime" HPR
2-stroke Oil inyo the Fuel.
We were so obsessive that after 500 hours when old mate pulled the Exgaust off to look indide, the Pistons still had the
Circumfrential
Grinding-Grooves in the
Aluminium Sidewalls,
The Piston Skirts had never touched the
Cylinder Liners...
So, be fastidious, and the Rotax will serve you well.
I wonder if that
Inflatable Rubber Ducky will have
Sufficient hydrodynamic stability in
Pitch, particularly in choppy water..., to work out in an
Ekranoplane ; it's pretty short, and wide.
Water is a LOT more
Energetic than is
Air at
30 or 50 mph,
Per cubic Foot of
Contact Area...
Will your Horizontal Stabiliser and Elevator be
Large enough and given a
Sufficiently long
Moment-Arm,
As to be able to debate the point, when it comes to
Argueing with a Wave which is smacking the
Bow into a Pitch-up ;
And your Elevator is attempting to keep the Nose down
To avoid
Overpitching, climbing out of
Ground Effect, then
Stalling..., & either
Diving or
Spinning back down...?
The majority of the Ground Effect Vehicles, of which I'm aware at least, seem to have a
Hull with a wetted Length that's rather longer than the
Wingspan...
I've assumed the noticable long thin hull was both to reduce Hydrodynamic Drag, and for better damping of
Pitch oscillation when
Waterborne...(?).
It'll be an interesting project.
Stay safe.
;-p
Ciao !
Thanks for the very intelligent comment. I don't know the answer to the question of pitch oscillation of a short hull and problems with the extra lift being generated by sudden increases in the angle of attack.
Where I'm planning to operate is a large estuary. As this craft will only be operating in very light winds the water will be calm and little chop is expected.
The estuary gets choppier the further out to see you go so testing can be done progressively, I think.
The elevator area I've copied from two other wing in ground effect craft.
James Greenberger and Kester Haynes. Here is kester in choppy water bouncing off the waves trying to get airborne. His floats are longer than my Rib so you have a point.
th-cam.com/video/Fj2XR17qg3Q/w-d-xo.htmlsi=maJwVESQoEfkbsRt
I'm in regular contact with James and kester so will ask them about the shorter hull. 👍
Thanks for the info on the Rotax.
@@Ben-Dixey
Thanks,
No worries...
Cool, as long as you're onto the Hull-Length issue and are keeping an eye on the Pitch thing.
Smooth Water will help a lot, too.
I wasn't expecting the link to go to Bear Grylls' Channel..., I usually think of him Rock-Climbing in the Jungle looking for a Snake, to eat it Raw (!).
Kester Haynes certainly was bouncing around from Crest to Crest before becoming airborne, but with those Floats their length did seem to damp the pitching..., apparently because to lift their noses the sterns have to be submerged, and being hollow (or foam-filled ?) even the trailing Edges are buoyant..., a long way back.
I'm trying to figure out whether it will be a real issue or an imaginary one, and if real - whether a small Float (maybe a 2 or 3 litre Plastic Coke-Bottle, base-forward for streamlining..., fixed under the Tail ; would help with damping any Tail-down moment ,- or whether the added Hydrodynamic Drag when the Float gets wet would hinder acceleration, right when any such extra Drag would be most unhelpful ?).
I reckon you'll have more data when you've had it on the Water..., it might not be any problem at all...; but it can't hurt to think about it in advance..., in case it causes hassles.
Keep on keeping on.
Stay safe.
;-p
Ciao!
@@WarblesOnALot Point taken, Kester's floats are 4m long, my Rib is 3.5m long so there is a difference. It will be interesting to find out. As with the helicopter I will report my findings.
I sort of have loose plans to build aluminium catamaran floats in the future, will see how things develop.
If you Google kester Haynes k42 aqua plane you will find his website where there is a video of the first flight.
Back then he didn't have the aircraft floats instead he used a Zapcat rib.
It's an exciting video as he didn't have a pilots licence back then.
@@Ben-Dixey
Cool !
I suspect the long Catamaran made of Aircraft type Floats might be a good way to go.
I'm a bit of an Internet Luddite, actually, never had a Computer, my daughter created my Channel & bookmarked it onto my prepaid Mobile Phone...; and I keep it Cookie & Virus free by not following Links away from YT, nor "surfing the Net" - rather, I merely "play on YT".
So I'll take your word about his first flight.
I live atop the Great Dividing Range, and there's no big flat Water within about a hundred miles, otherwise I would be very tempted to have a go at building something like the German Trimaran GEV which I saw on TV as a kid...; and up here it's the full Levitation Thing and climbing up high enough to be able to cope with Engine Failure by Gliding to a Clearing - or stay on the Ground, kind of thing.
Anyway, stay safe.
;-p
Ciao !
Watching Aquaplane K42 videos I have some ideas to improve longitudinal control, Ben. Are you using a forum to bounce ideas around?
I would like to hear any ideas you have Martin. I haven't posted on any forum. Are you a part of any forums that you think would be particularly suited ?
@@Ben-Dixey , not a forum but I was involved in an aerobatic electric aircraft project at Cranfield that didn't go anywhere at the time (we were all busy). Biggest problem with operating in ground effect is the longitudinal transient response time. You can see it in the K42 videos: pilot (Kester one assumes) puts in an input to climb, elevator causes the fuselage to change angle, then the wing eventually climbs. So there is a lag in the response that increases pilot workload.
What you wants is a flapevatoron system. This is a mixing of control inputs to flap, aileron, and elevator. For longitudinal speed stability you need to put mass centre slightly ahead of main wing so that horizontal tailplane is having to counteract. It is referred to as longitudinal dihedral in the text books. If you connect flap to elevator then you get the desired longitudinal control and speed stability but without the response lag. You also have to mix aileron and flaps, hence flapevatoron system. Only issue is need to put a trim system in to counteract the control force, but this is done all of the time in aircraft.
Your project is the perfect showcase to demonstrate the viability of this system...
Interesting, so the ailerons would flap down to increase the lift of the wing during the up elevator ?
Regarding the location of mass I believe this needs to be located between the 25% chord and 40% chord of the wing. I think in ground effect the centre of pressure starts at 40% and moves forward as height increases. Somewhere between the two would be the compromise ?
@@Ben-Dixey , yeah that's the mechanism. Flaperons are already used on high performance gliders, so nothing new there. The new bit is combining flap and elevator. You tune the flap to elevator ratio so that the main_wing and horizontal_stabiliser always produces zero moment about the mass centre, so only a lift force. Then it's a question of optimising for least drag over the flight speed range, and ensuring docile trailing edge (and flap) stall characteristics.
For a simple wing the centre of lift will typically be between 25% and 40% chord, depending on camber and AoA. For an aircraft in flight you want the mass centre to be a little forward of the main wing so that as the aircraft speeds up there is a pitch up tendency, and as the aircraft slows down there is a pitch down tendency. This reduces pilot workload, but there is a trivial trim drag penalty from the elevator pushing down against main wing. In practice the elevator is affected by downwash from main wing which will reduce trim drag. (The argument for Canards is that they avoid this trim drag, but you get the canard tip vortices affecting main wing which normally makes drag worse.)
For an aircraft that is designed to fly continuously in a fully held off landing then speed stability will be less of an issue. However you want the aircraft to reject gusts, so to my mind having mass centre ahead of wing still sounds like a wise idea. I can use that speadsheet to generate some charts when you have an idea about masses and wing planform. Whole point of the exercise is to reduce pilot workload, hence fatigue, hence mistakes.
But, I would definitely bounce this stuff off Kester Haynes as theory guided by experiment is always the best solution. His experience might be different from my short duration extended glider landings down airfields. It may be that he recommends putting mass centre on wing centre of pressure, in which case the flapevatoron system would be all flap and no elevator...
Great help Martin. I'm so glad you are willing to chip in with ideas and thoughts. I'm writing it all down so that I can eventually make informed design decisions. It helps when I've got two flying examples and two people willing to share the details with me. I can compare the theory with actual data.
I'll speak with Kester about your flapevateron idea and find out where his centre of mass is located. 👍
🎉🎉can’t wait 👍
😊👍
beware that self-sinking feature,,,, unless you find the aftermarket submarine option
😉👍
how much do u want for the rotax ??
Need to keep it at the moment I'm afraid, will let you know if I decide to sell it.
awwww dad!!!!!!! :)
👍
The blue head 582 is the most powerful 582 Rotax built. When you say fly are you talking about in ground effects or to actually fly? If actually flying is the idea the you will need to change the prop. P factor will be way to much with an airboat prop. Look up flying hovercraft. I built a house here on a creek we flew at in ground effects for years. No need for ailerons just basic tail and most use blue head 582's. Any way good luck.
Hi, thanks for the info. Yes I want to fly in ground effect only. I'm doing some training in a fixed wing microlight and it's fun but low to the ground I think is where I'd rather be. The prop is from the Polaris fib and I do have the flex wing. When I'm finished having fun in ground effect I might get it back up together as the fib configuration.
What machine did you fly in ground effect ?
The first one I built was a Scat 2 Hovercraft 10ft long I converted to a Hirth 625cc 65hp Fan cooled it's what you need on your helicopter with 2.6 reduction with 9 blade ducted fan. I put 2 aluminum cross tubes on it with 5 bows on each side with rip stop fabric just on top. Added the elevator on the DF shroud so I just had 3 controls throttle , elevator and rudder. After that found a Neoteric with larger 9 blade fan duct 300hp Kawasaki with super charger off Jetski. Set it up the exact same way but was so much nicer. Could seat 4 and fly 3-4ft off the water at about half throttle. I built a house in the country 30 years ago with my wife two daughters on 100 acres looks like a state park with a really nice creek running through it right to the Mississippi river 10 miles down stream. I've loved designing and building rotorcraft, hovercraft, airboats since I was little. Just about to finish a machine that works like a autogyro buts electric with several fail safes built in. Will fly like a air ATV around the farm. Plan to start posting next week. I'll video some pics of machines I've built over the years. I worked with NASA on the Mar rover project that flew on Mars. I designed and build what Langley ask for but they didn't choose the machine ended up going with another companies design in the end.
Wow! 😳 yes please put up some videos on your channel. Would love to see what you speak of have subscribed to your channel. 👍
ChecK out the link below for Jabiru info, Be careful not too over cook the cylinder heads !!!!!!!!!
www.lightaircraftassociation.co.uk/engineering/TADs/E03%20JABIRU.pdf
Thanks for that Julian, much appreciated. 👍