I just love the idea of the mini-chinook, it's such an underrated format. high speeds from the low frontal area and great lift from the low disc loading. the linkages are not too complex, especially if you dont worry about the auto pitch compensation. I'm loving the WIG idea too, cant wait.
Great direction change, Ben. I think tackling aircraft stuff in smaller bites is definitely the way forwards. You'll still need to understand fixed wing controls for pitch, roll, and yaw so this will be good experience. It also neatly sidesteps the concerns about getting a flying machine certified. Ground effect is a lot of fun in gliders, with airbrakes shut, because you can stay airborne for the full length of the airfield. For rotary wings, you've more or less nailed how delta3 uses aerodynamic forces to get the blade tip path plane to stay aligned to the fuselage. The hiller paddles are a little more complicated as you have to think of them as a servo control for the main blade. Effectively the swash plate flies the flybar, which acts as a gyroscope. This means that the rotor is being controlled by a gyroscope that is always seeking to keep the same plane. So the effect is that the main rotor behaves as if it had more gyroscopic inertia. So a given swash plate pitch or roll input will produce lower pitch rates and roll rates in the rotor tip path plane. Larger helicopters often still use gyro stabilisation, but it is normally done in the control system with the benefit of hydraulic servos. However, the Cabri G2 trainer has demonstrated that by simply increasing the rotor inertia you get the same effect. That is to say reduced pitch & roll rates for a given cyclic input. This also has the advantage of safer entry to autorotation, and flaring, as more kinetic energy can be stored in the rotor itself. Hope this helps...
Fantastic comment Martin 👍 thanks for the input, I had forgotten to mention the servo assistance from aerodynamic paddles. Do you think that is the main difference between Arthur young's stabiliser bar and Stanley Hiller's fly bar ? I didn't know that there is gyro stabilisation through hydraulics in larger helos. 👍 I can understand how a larger Inertia rotor would be a benefit in more ways than one. The cabri G2 seems well thought of. I was told a while ago that the reason the Robinsons don't need a stabiliser bar or fly bar was due to the height of rotor compared to the cg of the aircraft. It's much higher. I can see this creating a delayed response to cyclic inputs. The wig boat will be a new learning experience which I can't wait for. I know very little about fixed wing construction, thrust lines, planing hulls, centre of pressure changes in wig vehicles. To name just a few of the things required to understand.
@@Ben-Dixey , thanks. In larger helos it is called stability augmentation system (sas). The design was originally developed by Lockheed for the AH56 Cheyenne, but when this was cancelled Westlands picked it up for the Lynx. Lynx has a very high effective hinge offset, or rigid rotor. This produced a difficult to fly helicopter without the sas system. Nowadays sas is typical in large helicopters like the Merlin and S92 to reduce pilot workload during difficult missions. The Young and Hiller stability bars both use the gyroscopic effect of the bar to slow down the rotor pitch and roll rates for a given cyclic position. Remember how difficult that R22 was to hover? This is a combination of high pitch and roll rates for a given cyclic input, and a delay in response from pilot cyclic input to the fuselage following the teetering rotor. Both Young and Hiller systems were implemented to slow down the rotor rates and improve stability. The Hiller system is effectively an aerodynamic servo control. The Young system is just a control input mix so that the bar counteracts the cyclic input to make the rotor undercontrolled. This is required because the maximum range of longitudinal and lateral cyclic is set by the maximum speed required in the helo. You discussed 90 degree precession flapback in an earlier video. The cyclic movement has to be enough to counteract flapback, but the penalty is the potential to overcontrol the rotor. But, for my money the Cabri G2 is the neater solution of simply increasing the rotor inertia as this involves the fewest parts. By using hingeless blades then this also reduces the cyclic response delay. The blade moment also means you don't loose rotor control if you reduce positive gee. We discussed high effective hinge offset blades the other day. The effect is to increase the flapping frequency of the blade to be higher than the azimuthal sweep frequency. This means that the 90 degree lag of a teetering won't cut it, so you have to introduce delta3 angle to reduce the blade pitch lag from the swashplate. With rotor coning then there are aerodynamic reasons for delta3 too, which is why the robbie has it. Very wordy response, but I know you get the mechanical details.
Hi and thanks. Yes, ground effect vehicles are gaining in interest it seems. They look so much fun, the new project is more than underway, I've spent a lot of money and will update everyone soon. Plenty to discuss on design decisions and I think TH-cam knowledge will really help. Not a huge amount of content available on building a full scale wig vehicle.
Hi Ben, The Rotorcycle has a paddle bar, to allow for the 90 degree phase difference when controlled by a hanging stick, And not a floor cyclic stick. Also paddle bar absorbs pitch change vibrations coming back through the cyclic control stick. As someone else siad it acts as a servo.
Good stuff Ben. In newer RC helicopters, 'flybarless' has become all the rage. They still use a 90 degree hinge, but now precession and mixing are electronically controlled and programmable. If I were to attempt the build of a manned collective pitch heli, these days I'd probably follow along those lines. A ground effect flying boat sounds like a fantastic project, and I'm eager to follow along. Thanks for sharing such interesting and inspiring projects with us.
Thanks for the informed comment. 👍 Electric servos for controlling the swash plate on a full scale is something I'm considering. It would make a chinook less complicated on the control mechanisms.
Ben, glad to see you. I want to leave a note here so the algorithm takes notice. If we can figure out how to get it to you, you would be welcome to my hang glider Dacron fabric. I will never fly that one again.Shipping might be a killer, new might be cheaper.
👍 A helicopter is a massive machining task, everything has to be accurate and that takes a lot of time. Hopefully this project will come together much faster and will return more enjoyment through usage.🤞
Hi Ben, I love watching your all your adventures, I used to be a commercial helicopter pilot in Australia ( now UK ), I also had an opportunity to fly a prototype 8 seat WING IN GROUND EFFECT craft. I think the helicopter is a safer and easier beast to fly, it all gets a bit scary at speed, when all you want to do is gain some altitude, but can't. I felt as though lots of control inputs to maintain attitude a metre off the water at 60 knots. I looking forward to see what happens, Cheers
Thank you and interesting comment. I have zero experience with fixed wing or ground effect vehicles. I can understand how flying so close to the water could be a high work load for the pilot. Not something I'd considered actually. It will be interesting to experience. You see people doing all sorts of things on videos and never know until you try it what it's actually like. Hovering the helicopter was 90% stressful and 10% enjoyment but that would have improved with practise. Wonder if the same could be said for a wig boat?
Frizt, was the control challenge to maintain altitude? "In theory" lateral control should be easier, as the lower wing generates more lift. I think longitudinal long & short period oscillations fight altitude stability so you have to tell the aircraft to stay level. Literally a sustained held off landing.
At 2:15 the same experiment was done by the rotor stabilizing bar inventor (Arthur m. Young) in this youtube link (m.th-cam.com/users/results?search_query=birth+of+the+bell+helicopter+&sp=mAEA) titled "the birth of the bell helicopter part 1" exactly at 6:10. But I think that the system used in the RC model is a mixture of A. M. Young and hiller systems
Thanks 👍 yes that's where I got the idea from to observe the time lag. I forgot to mention the servo assistance that is given by the paddles. But messages by martin garrish in the comments understands it better than I do. I believe Arthur youngs stabiliser bar was heavy on the controls.
yes in deed; the the stabilizer bar makes the helicopter more stable but less responsive to control inputs. this system was the a trade mark for bell helicopter early models(the bell 47 and the famous bell huey) but abondonned in the AH-1 Cobra and replaced by tunable electronique stability augmentation systems
Bear in mind that WIG craft can be dangerous, specifically if they get some sudden upwards thrust on the nose. Many high-speed racing boats have been lost to this, so it's important to plan a countermeasure to restore horizontal flight if it happens.
Thank you, the centre of pressure change lifting the nose when coming out of ground effect. Wig vehicles have large tails to keep this under control I believe. I need to get the design right for sure. 👍
Very cool man, I wish you all the best of luck with your new project. Have you ever considered building an E-VTOL? Something like a Jetson one? Its a fairly simple concept. I am walking around with this idea of a 1or2 person E-vtol with the design of a lillium jet mixed with pantuo pantala focussing on the fly time en minimal payload. Where the big companies focus on transporting passengers and goods i want to have as much air time as possible just for the fun of it. I dont need to go fast. But there still needs to be room to correct you plane quickly. This makes it safer en easier to operate, since you can correct any forces working on the plane much easier. Also you can leave most of the mecanical engineering behind which in my opinion is always less safe to operate. Again, good luck. I will be looking forward to your videos. Best regards Jan from the Netherlands.
Hi, yes I have thought about it. The Jetson one is interesting and would be a lot of fun. Amazing diy projects channel is building something different, much more efficient than the Jetson but will only be for hovering in very low wind.
It's a consideration, the Gen 4 is a masterpiece of engineering and has the redundancy of multiple engines. Composite blades I think are a must but I wonder how it handles in any wind at all. 🤔
Hey, been watching a few of your videos, they are funny, educational and interesting to watch. Like it, subscribed. Yes spot on, blade 4003d not that it's done any 3d flying with me at the controls, well maybe once for a few milli seconds before hitting the ground. 😆
@@Ben-Dixey - likewise Ben - where my engineering per se is tainted with sarcasm etc and geared towards my beloved RC Heli's, YOU are actually doing it and I like many others, can only have the most upmost of respect for your tenacity, courage, patience and expertise. I was gutted for you after the failure of the drive shaft and really understood your pov about what to do going forward but - YOU'RE back and for that, I begin a slow respectful clap. Keep going and thanks for subscribing - I hope my little channel brings some light hearted relief. Best wishes.
orrrrr... you could go for the chinookish V-22 Osprey, just a Chinook at 90 degrees. I had considered this and make it fly by wire using Rotormast V-22 controller board. Driving the rotor controls via a proven control board for the base signal to drive amplifiers of each flight control element, whether mechanical or electronic would be interesting. The ekranoplan would be cool and worth watching too. You are super educational to watch. I think the channel name change is better than apparent random and forgettable alpha-numerics.
Thanks for the suggestion, the v-22 is another intriguing machine. Bet R&D was substantial when building that. Combining a twin engine plane and twin rotor helicopter is some project. Incredible when you think about it. My knowledge is more mechanical based but with help I'm sure I could involve electronic flight controllers. The v-22 idea if it could be tested unmanned would be the way to go.
I'm always nervous about life dependence on a mechanical system with electronic control. Only recommendation would be assume it will fail at some point then design it not to. This usually means that mechanical control is the got to solution for homebuild. Regarding planform then as Sergei Sikorsky once commented to me at a helicopter conference: keep the disk loading down. The AW609 was a commercial offshoot of the V22, but high autorotation descent rates means that 20 years after first flight it still isn't certified. A lot of the new e-vtol designs make the same mistake, so I take their certification timelines with a pinch of salt. Whatever power system you use assume that it will fail at some point then design it not too. My money is on Jaunt Air Mobility for air taxis (interesting wing & rotor compound design). That said, there are many technical advantages of side-by-side lateral symmetry as long as you can live with the increased planform width for a sensible disk loading. Overlapping the rotors will reduce rotor induced power, but we are talking about helicopters where laminar flow is just unachievable. The Chinook was Piaseki's solution to heavy lift in a small planform. There are some advantages with reduced power for an anti torque solution, and they can operate with sensible payload at high altitude. Whether you would want that long driveshaft to keep synchronisation in a homebuild design is an interesting debate. Again, design it not to fail but assume that it could.
Good points Martin on dependable mechanical linkages for control vs electronics. Interesting what Sergei Sikorsky said about disc loading a phrase I've heard a lot. Its just a shame that low disc loading comes at the price of increased hangar space. The driveshaft between the two rotors on a tandem is a worry it if breaks but synchronisation is less so because one rotor is higher than the other I believe. Perhaps multiple V belts instead of one driveshaft would be less likely to result in a catastrophic failure. I think Believe Boeing had a drive shaft failure with the development of the chinook.
@@Ben-Dixey , rotors don't need to be going around in the hanger 😉. A smart fella like yourself should be able to figure a reliable way to stow the rotors when playtime is over. Hanger and apron space is the main reason that teetering rotors with brakes for fore-aft parking have dominated market. With a 3 blade system then there are neat systems to fold all three blades along the tail boom. Obviously the very real risk is that the retaining pins don't get fitted or fall out in flight. There is the idea of upscaling a quadrotor so that teetering can still provide pitch and roll moments at reduced gee with differential collective pitch. As long as the thing can safely autorotate to the ground in the highly unlikely event of a drive failure 😟. Then the rotor booms could be folded to stow the machine, and the retaining pins more solid and easier to see. Just my brainstorm...
Ground effect boats or planes are dangerous. Look at how close the wing gets to the water. If you stuff up, or get a wind gust, you are fish food. Fully articulated is the best, and it is not very complicated, that is what I chose after a lot of research and comparison. Look at the MD500 system, or the AS350. Both are quite simple and low maintenance. Designing such a system for a small helicopter is easier. When you spread the load over multiple blades it also becomes easier in my opinion. My design is 6 blades. If you have no intention on flying fast or high, go for a rigid system such as that on a BO105 as its simpler again. The Robinsons were designed to be as cheap as possible, from a mass production with a target market of the low income it must be kept very simple. For one off homemade not so much. The stability alone of a fully articulated rotor outweighs a teetering hinge. I looked at making a model, and a simple helicopter and slowly climb the ladder, but it ends up being more expensive and complicated and time consuming making several versions than just tackling a design that is a little more complex. I enjoy your humour and videos, best of luck Ben.
Hi John, thanks for the comment, the wing tips of a wig boat coming into contact with the water is a concern but can be protected against. James Greenberger added small sponsons to the trailing edge and I believe has tested the feature. The wig boat idea seems less dangerous than a homemade helicopter but until you experience it I suppose it's difficult to draw conclusions. One of the biggest concerns I had with mine was that driveshaft right behind me, a different design getting that feature further away or incased would have been safer. Lack of any rotor overrun was another potentially dangerous feature. Your helicopter sounds like it will be safer than mine in those respects but fully articulated rotors can experience ground resonance as you will know, which can result in the total destruction of the helicopter. Getting this right is going to be critical to safety and that's before you have even left the ground. It's difficult to quantify how dangerous something actually is, it comes down to opinion most of the time. I think homemade helicopters can be safe if designed correctly but there will always be risk. The bo105 is an awesome rotor head How goes the development on your mini MD500 ?
@@Ben-Dixey I dont see the point in something that doesn't fly, and is less practical than a boat. The sponsons may help, but still. I thought for your heli the best option would be having the engine tilt with the rotors, so no need for a flexible driveshaft. a mechanical or electronic governor could have fixed the engine overrun concern. As for ground resonance, it is a concern and have not overlooked it. Having more rotors that are lighter means they require less movement in lead lag. They are less susceptible to creating an imbalance, although not impossible. Most of the resonance issues is with 3 heavy rotors. It is untested so far and complicated, but there are many factors that induce resonance, mass, rpm, drag, the range of movement that occurs and that is permitted. For test flight I will remove the lead lag dampers on rotors so that there is no chance of an imbalance occurring. For testing and hovering this will be acceptable, it is only in forward flight that lead lag is really required. I will have dampers on the landing gear, plus I intend to have a wheel dolly or larger skids under the landing gear for first flight so that it can move freely side to side. I do intend to make pontoons/floats also, so could even use the lagoons on the farm as a shock absorber. My project is slowly going. Working on transmission and doing oil testing. Stuck on what dash to use, so many options, You can spend 5-20-k on a screen alone, I want to choose the right one. I procrastinate and then a new model or product comes out, far out. I still have a lot to do, still have to make a pressure suit for high altitude and hope that it doesn't pop, lol. its all fun, thats the main thing.
Sounds good to me and that is the main point, having fun. You can't get much more excitement than designing, building and testing a homebuilt helicopter. The point of the ground effect boat is primarily to have fun and low to the ground is where I think the most fun can be had. My helicopter was only intended for hovering but a achieving just that isn't easy. I suspect it's a good idea to test yours without the dampers as long as the wind is calm. A head wind will give the same scenario as forward flight. How do you go about balancing multi bladed rotors ? Not something I've considered.
@@Ben-Dixey From my understanding, at least here in Australia is a ground effect boat only requires a boat licence, so cost is saved there. All flight tests will be conducted in the early hours of the morning. 2-4am is usually very calm. I have thought of that. Dampers are to reduce the stresses applied to the rotors to prevent fatigue damage, and this is an occurrence at higher speed. For short term, it is not an issue. As for balancing, it is not all that different from a rigid or semi rigid. The overall weight and centre of balance must be the same. For tracking balance, the rotors have a trim tab fixed to the blade so you can make them all rotate on the same axis by bending it slightly up or down. I have not made my rotors yet, but intend to make a few more for stress testing. I have designed the rotor head to accommodate small cameras that will be able to overwatch each rotor on a screen in the cockpit for tracking and movement. I keep thinking of ways to add complexity. We have so much technology and products available to the average person now, it makes possibilities so much easier. Off topic now, but little cameras I think are great, you can have them pointing in all directions, in the engine compartment, looking beneath, watching the tail boom. One of my concerns is pulling hard rearward on the cyclic and having the rotor hit the tail. By having cameras I can see how close it gets. After I am confident with a hover, I was thinking of making a mock up cockpit and using radio control and fpv for more adventurous testing. I do worry, I will be over excited and try and fly fast too quickly. I figure Ill just chase kangaroos around for the first few hundred hours. Anyway, enough from me.
th-cam.com/video/gyLwK7Akx2I/w-d-xo.html give some thort to par thrust for initial lift at low ground speed .. im putting the big motor cycle engine at the cg and a long propshaft to a cv joint and thrust bearing steering knuckle to tilt the prop up a tad at takeoff . and yes my cv boots r holding up at 2000 rpm on a test bed .. motorbike sprocket to driveshaft adaptor from kit cars .. takeoff in 2nd .. shift to 3rd for cruise . .. jeeeez what a wanker i am
Thanks 👍 Par thrust is a smart addition I think, I don't know if there are any drawbacks to it other than the more complicated drive systems. What stage are you at with your build ?
@@Ben-Dixey iv done a full size mockup in cheap plywood that becomes paturns for a stitch and glue boat with wings and worked out all the machanical drive train stuff on a test bench ,, thats done . thin marine ply and epoxy next oh joy . im a steel boat man . and epoxy tries my patience oh .. the canard is pitch control btw and having the engine inside is less drag . and lower cg ..i love james wings nice and simple easey to extend
also built a 3meter r c model to test P A R thrust .and fully flying canard . its very effective .. jumps off the water . . water is very sticky and draggy and hard when hit at speed and much bumpeyer than an air strip
Underslung rotor systems are inherently dangerous. R-22's crash regularly from negative g's. Many a video of people dying from the tail boom being chopped off mid flight. I would not even ride in one myself, but pick your poison carefully. 3 blades at the least. 2 blade rotors are not a fun ride at speed. Notice the cyclic of any video when in a Robinson. The shaking is abysmal. The stresses of those system take their toll overall pretty quickly. Rotor inertia in a Robinson is terrible. JetRangers are better but look at the mass of those blades. The ride in a JetRanger is awful at speed.
Are you speaking from experience or just parroting what you've heard in comments? All of my flight hours are in Robinsons, and your comment is extremely disingenuous. Firstly, low-G pushover IS a dangerous condition for any 2 blade rotor system, but Robinson's don't crash "regularly" because of this. In fact, mast bumping makes up a small percentage of Robinson accidents. A vast majority of Robinson accidents are due to power management (or lack thereof) and striking obstructions like power lines. For how many Robbies are airborne, mast bumping is extremely rare. Furthermore, it is a condition that can (and does) happen in other 2 bladed rotor systems, there's just more Robbies in the air than all the other 2 bladed birds combined, so you see it more often. Also, the cyclic on Robinsons does not vibrate violently, at least not on a properly balanced one. You may be confusing deliberate inputs with vibration, as the R22 requires a lot of cyclic input at a hover, particularly in windy conditions, because of how "twitchy" the bird is. Hovering a R22 is a very engaging process. The R44, on the other hand, has zero vibration and rarely requires more input than some pressure on the cyclic unless you're doing something rowdy like wrangling cattle. I dunno man. Your comment just reeks of someone who has never sat in a Robinson and is just talking out of their ass after watching the R44 Cadet crash that happened in Texas last year.
@@Maverickib As you have never flown anything but Robbies I can assure you that you are biased. 50 hours of factory certified training was required by the FAA and insurers when they were killing people pretty regularly at the beginning. Why? Bad design that was certified by idiots at the FAA. That rotor system was developed from autogyro systems. Boosted hydraulics are always smoother, but another failure point. Load up an R-22 at max gross on a hot day and do me a hovering auto from 10 feet. Inertia in that rotor system is abysmal. How many full touchdown autos have you done? I did over a 100 in my initial training. I used to teach full touchdown autos. H300's and JetRangers. I've had 5 engine failures, 1 from hover. Never bent a helicopter or damaged one in 4000 hours of flying. If you gave me a Robbie I wouldn't do anything with it but hope to sell it. The cyclic setup is comical just in itself. Obviously you're a bit butthurt over my comment, but I stand by my 45 years experience. Good luck with your choice, but I'm not a fan of Robbies. They became popular because they are simple and cheap to make. The only commercial operators are training, cow scaring and sightseeing for a reason. Cheap. Nobody is going to hire you with just Robbie experience except Robbie operators. Try getting HEMS or Commercial ride with that as your resume. Not going to happen. 100 hours of Astar or 407 time would be a better bet. The Military owns zero Robbies in the USA. Cheap and twitchy. When starting an R-22 they look like a mule crapping sandspurs they shake so bad. Not good for any drive components lifespan, and if I was uninformed would probably not know the difference. Cheap way out and didn't conflict with standing patented systems. My advice would be fly something with more than 2 blades and see the difference for yourself. Fly safe.
I just love the idea of the mini-chinook, it's such an underrated format. high speeds from the low frontal area and great lift from the low disc loading. the linkages are not too complex, especially if you dont worry about the auto pitch compensation. I'm loving the WIG idea too, cant wait.
Thank you. 🙂 the auto pitch you mention is that the mixing of collective into the swash plates ?
Looking forward to hearing more. Best of luck!
Thank you 👍😊
I didn't think you'd quit. Looking forward to the next leg of your adventure.
😊👍
Great direction change, Ben. I think tackling aircraft stuff in smaller bites is definitely the way forwards. You'll still need to understand fixed wing controls for pitch, roll, and yaw so this will be good experience. It also neatly sidesteps the concerns about getting a flying machine certified. Ground effect is a lot of fun in gliders, with airbrakes shut, because you can stay airborne for the full length of the airfield.
For rotary wings, you've more or less nailed how delta3 uses aerodynamic forces to get the blade tip path plane to stay aligned to the fuselage. The hiller paddles are a little more complicated as you have to think of them as a servo control for the main blade. Effectively the swash plate flies the flybar, which acts as a gyroscope. This means that the rotor is being controlled by a gyroscope that is always seeking to keep the same plane. So the effect is that the main rotor behaves as if it had more gyroscopic inertia. So a given swash plate pitch or roll input will produce lower pitch rates and roll rates in the rotor tip path plane.
Larger helicopters often still use gyro stabilisation, but it is normally done in the control system with the benefit of hydraulic servos. However, the Cabri G2 trainer has demonstrated that by simply increasing the rotor inertia you get the same effect. That is to say reduced pitch & roll rates for a given cyclic input. This also has the advantage of safer entry to autorotation, and flaring, as more kinetic energy can be stored in the rotor itself.
Hope this helps...
Fantastic comment Martin 👍 thanks for the input, I had forgotten to mention the servo assistance from aerodynamic paddles. Do you think that is the main difference between Arthur young's stabiliser bar and Stanley Hiller's fly bar ? I didn't know that there is gyro stabilisation through hydraulics in larger helos. 👍
I can understand how a larger Inertia rotor would be a benefit in more ways than one. The cabri G2 seems well thought of.
I was told a while ago that the reason the Robinsons don't need a stabiliser bar or fly bar was due to the height of rotor compared to the cg of the aircraft. It's much higher. I can see this creating a delayed response to cyclic inputs.
The wig boat will be a new learning experience which I can't wait for. I know very little about fixed wing construction, thrust lines, planing hulls, centre of pressure changes in wig vehicles. To name just a few of the things required to understand.
@@Ben-Dixey , thanks. In larger helos it is called stability augmentation system (sas). The design was originally developed by Lockheed for the AH56 Cheyenne, but when this was cancelled Westlands picked it up for the Lynx. Lynx has a very high effective hinge offset, or rigid rotor. This produced a difficult to fly helicopter without the sas system. Nowadays sas is typical in large helicopters like the Merlin and S92 to reduce pilot workload during difficult missions.
The Young and Hiller stability bars both use the gyroscopic effect of the bar to slow down the rotor pitch and roll rates for a given cyclic position. Remember how difficult that R22 was to hover? This is a combination of high pitch and roll rates for a given cyclic input, and a delay in response from pilot cyclic input to the fuselage following the teetering rotor. Both Young and Hiller systems were implemented to slow down the rotor rates and improve stability. The Hiller system is effectively an aerodynamic servo control. The Young system is just a control input mix so that the bar counteracts the cyclic input to make the rotor undercontrolled. This is required because the maximum range of longitudinal and lateral cyclic is set by the maximum speed required in the helo. You discussed 90 degree precession flapback in an earlier video. The cyclic movement has to be enough to counteract flapback, but the penalty is the potential to overcontrol the rotor.
But, for my money the Cabri G2 is the neater solution of simply increasing the rotor inertia as this involves the fewest parts. By using hingeless blades then this also reduces the cyclic response delay. The blade moment also means you don't loose rotor control if you reduce positive gee. We discussed high effective hinge offset blades the other day. The effect is to increase the flapping frequency of the blade to be higher than the azimuthal sweep frequency. This means that the 90 degree lag of a teetering won't cut it, so you have to introduce delta3 angle to reduce the blade pitch lag from the swashplate. With rotor coning then there are aerodynamic reasons for delta3 too, which is why the robbie has it.
Very wordy response, but I know you get the mechanical details.
Awesome to see your great explanation on the head tilt thing. The ground affect idea is something I have been thinking about a lot 👍
Hi and thanks. Yes, ground effect vehicles are gaining in interest it seems. They look so much fun, the new project is more than underway, I've spent a lot of money and will update everyone soon. Plenty to discuss on design decisions and I think TH-cam knowledge will really help. Not a huge amount of content available on building a full scale wig vehicle.
Thanks for the mention mate. I can't wait to see progress on your new project. Wing in ground effect is extremely fun
Thanks James, hope you didn't mind me using a few short clips of yours. If it's as fun as it looks I can't wait!
Hi Ben, The Rotorcycle has a paddle bar, to allow for the 90 degree phase difference when controlled by a hanging stick, And not a floor cyclic stick. Also paddle bar absorbs pitch change vibrations coming back through the cyclic control stick. As someone else siad it acts as a servo.
Hi Peter, I'll have a look at the rotorcycle controls and try and understand it.
Good stuff Ben. In newer RC helicopters, 'flybarless' has become all the rage. They still use a 90 degree hinge, but now precession and mixing are electronically controlled and programmable. If I were to attempt the build of a manned collective pitch heli, these days I'd probably follow along those lines.
A ground effect flying boat sounds like a fantastic project, and I'm eager to follow along. Thanks for sharing such interesting and inspiring projects with us.
Thanks for the informed comment. 👍
Electric servos for controlling the swash plate on a full scale is something I'm considering. It would make a chinook less complicated on the control mechanisms.
Ben, glad to see you. I want to leave a note here so the algorithm takes notice. If we can figure out how to get it to you, you would be welcome to my hang glider Dacron fabric. I will never fly that one again.Shipping might be a killer, new might be cheaper.
Thanks very much David, that's a very kind offer, I'll bare it in mind, when the time comes 😊👍
im glad that you have put the fling wing aside .
Great Vid Ben! Very interesting. Love your optimism and willingness to learn😎🙌
Thank you. I love trying to learn how things work. If they taught this stuff at school I would have done a huge amount better.
Really looking forward to the WIG project, far less labour intensive than the heli if nothing else!
👍 A helicopter is a massive machining task, everything has to be accurate and that takes a lot of time. Hopefully this project will come together much faster and will return more enjoyment through usage.🤞
The Flybar also acts as a servo for the cyclic.
👍
YAY for the new project Ben!!! Can't wait for build and testing vids. Great to see you back!! 😀😀😀😀👍👍👍👍
😊 thanks a lot 👍
Hi Ben, I love watching your all your adventures, I used to be a commercial helicopter pilot in Australia ( now UK ), I also had an opportunity to fly a prototype 8 seat WING IN GROUND EFFECT craft. I think the helicopter is a safer and easier beast to fly, it all gets a bit scary at speed, when all you want to do is gain some altitude, but can't. I felt as though lots of control inputs to maintain attitude a metre off the water at 60 knots. I looking forward to see what happens, Cheers
Thank you and interesting comment. I have zero experience with fixed wing or ground effect vehicles. I can understand how flying so close to the water could be a high work load for the pilot. Not something I'd considered actually. It will be interesting to experience. You see people doing all sorts of things on videos and never know until you try it what it's actually like. Hovering the helicopter was 90% stressful and 10% enjoyment but that would have improved with practise. Wonder if the same could be said for a wig boat?
Frizt, was the control challenge to maintain altitude? "In theory" lateral control should be easier, as the lower wing generates more lift. I think longitudinal long & short period oscillations fight altitude stability so you have to tell the aircraft to stay level. Literally a sustained held off landing.
@@martingarrish4082 exactly ,a sustained held off landing.
Fantastic - I'm looking forward to it.
Always interesting stuff - good luck with your next project
Nice.. Can't wait.
Can't wait Ben 😁 compulsive viewing for me mate 😁😁🤘🤘🤘
Thank you 😊
Yes WIG, Always wanted to make one
You could make one in your sleep Julian.
At 2:15 the same experiment was done by the rotor stabilizing bar inventor (Arthur m. Young) in this youtube link (m.th-cam.com/users/results?search_query=birth+of+the+bell+helicopter+&sp=mAEA) titled "the birth of the bell helicopter part 1" exactly at 6:10. But I think that the system used in the RC model is a mixture of A. M. Young and hiller systems
Thanks 👍 yes that's where I got the idea from to observe the time lag. I forgot to mention the servo assistance that is given by the paddles. But messages by martin garrish in the comments understands it better than I do. I believe Arthur youngs stabiliser bar was heavy on the controls.
yes in deed; the the stabilizer bar makes the helicopter more stable but less responsive to control inputs. this system was the a trade mark for bell helicopter early models(the bell 47 and the famous bell huey) but abondonned in the AH-1 Cobra and replaced by tunable electronique stability augmentation systems
@@abrahamjushua9491 thanks for the info. 👍👍
Yes!! Can't wait 👍🏴
Thanks for the support 👍
I have no idea on how gyroscope precision works on coaxial, but with a tail boom fuselage an aerodynamic precision's is more sensitive
Bear in mind that WIG craft can be dangerous, specifically if they get some sudden upwards thrust on the nose. Many high-speed racing boats have been lost to this, so it's important to plan a countermeasure to restore horizontal flight if it happens.
Thank you, the centre of pressure change lifting the nose when coming out of ground effect. Wig vehicles have large tails to keep this under control I believe. I need to get the design right for sure. 👍
Very cool man, I wish you all the best of luck with your new project.
Have you ever considered building an E-VTOL? Something like a Jetson one?
Its a fairly simple concept. I am walking around with this idea of a 1or2 person E-vtol with the design of a lillium jet mixed with pantuo pantala focussing on the fly time en minimal payload. Where the big companies focus on transporting passengers and goods i want to have as much air time as possible just for the fun of it. I dont need to go fast. But there still needs to be room to correct you plane quickly. This makes it safer en easier to operate, since you can correct any forces working on the plane much easier.
Also you can leave most of the mecanical engineering behind which in my opinion is always less safe to operate.
Again, good luck. I will be looking forward to your videos.
Best regards
Jan from the Netherlands.
Hi, yes I have thought about it. The Jetson one is interesting and would be a lot of fun. Amazing diy projects channel is building something different, much more efficient than the Jetson but will only be for hovering in very low wind.
Fair enough move ,
new name of channel is pretty cool too.
Thanks brother
Cheers for the continued support. 👍 appreciate it.
@@Ben-Dixey it's all our pleasure, cheers for your continued work and reporting us so interestingly.
Those Wig craft, you've got to have a calm sea, or a lake.
What about something like the genH4?
It's a consideration, the Gen 4 is a masterpiece of engineering and has the redundancy of multiple engines.
Composite blades I think are a must but I wonder how it handles in any wind at all. 🤔
Good work 😊
Thanks Richard! Is this the Richard I went to college with ?
@btd1982 Sure is mate!
You were the smart one, I was the dumb one. 😆
@@Ben-Dixey Now you're being daft. Not that I've done any engineering for a long time, but if you need a hand.....🙂
Thanks Richard, I'll bare it in mind. 👍😊 stop by sometime!
awesome! Good to see you back Ben! I'll guess the heli. e-flite Blade 4003d ;-)
Hey, been watching a few of your videos, they are funny, educational and interesting to watch. Like it, subscribed. Yes spot on, blade 4003d not that it's done any 3d flying with me at the controls, well maybe once for a few milli seconds before hitting the ground. 😆
@@Ben-Dixey - likewise Ben - where my engineering per se is tainted with sarcasm etc and geared towards my beloved RC Heli's, YOU are actually doing it and I like many others, can only have the most upmost of respect for your tenacity, courage, patience and expertise. I was gutted for you after the failure of the drive shaft and really understood your pov about what to do going forward but - YOU'RE back and for that, I begin a slow respectful clap. Keep going and thanks for subscribing - I hope my little channel brings some light hearted relief. Best wishes.
Thanks for the very kind comments! 😊👍
I love WIGE 👍
That's good, I hope the new project is of similar interest. New video coming very soon on the WIGE project, I've spent a lot of money already. Ha !
orrrrr... you could go for the chinookish V-22 Osprey, just a Chinook at 90 degrees. I had considered this and make it fly by wire using Rotormast V-22 controller board. Driving the rotor controls via a proven control board for the base signal to drive amplifiers of each flight control element, whether mechanical or electronic would be interesting. The ekranoplan would be cool and worth watching too. You are super educational to watch. I think the channel name change is better than apparent random and forgettable alpha-numerics.
Thanks for the suggestion, the v-22 is another intriguing machine. Bet R&D was substantial when building that. Combining a twin engine plane and twin rotor helicopter is some project. Incredible when you think about it. My knowledge is more mechanical based but with help I'm sure I could involve electronic flight controllers. The v-22 idea if it could be tested unmanned would be the way to go.
I'm always nervous about life dependence on a mechanical system with electronic control. Only recommendation would be assume it will fail at some point then design it not to. This usually means that mechanical control is the got to solution for homebuild.
Regarding planform then as Sergei Sikorsky once commented to me at a helicopter conference: keep the disk loading down. The AW609 was a commercial offshoot of the V22, but high autorotation descent rates means that 20 years after first flight it still isn't certified. A lot of the new e-vtol designs make the same mistake, so I take their certification timelines with a pinch of salt. Whatever power system you use assume that it will fail at some point then design it not too. My money is on Jaunt Air Mobility for air taxis (interesting wing & rotor compound design).
That said, there are many technical advantages of side-by-side lateral symmetry as long as you can live with the increased planform width for a sensible disk loading. Overlapping the rotors will reduce rotor induced power, but we are talking about helicopters where laminar flow is just unachievable. The Chinook was Piaseki's solution to heavy lift in a small planform. There are some advantages with reduced power for an anti torque solution, and they can operate with sensible payload at high altitude. Whether you would want that long driveshaft to keep synchronisation in a homebuild design is an interesting debate. Again, design it not to fail but assume that it could.
Good points Martin on dependable mechanical linkages for control vs electronics. Interesting what Sergei Sikorsky said about disc loading a phrase I've heard a lot. Its just a shame that low disc loading comes at the price of increased hangar space.
The driveshaft between the two rotors on a tandem is a worry it if breaks but synchronisation is less so because one rotor is higher than the other I believe.
Perhaps multiple V belts instead of one driveshaft would be less likely to result in a catastrophic failure.
I think Believe Boeing had a drive shaft failure with the development of the chinook.
@@Ben-Dixey , rotors don't need to be going around in the hanger 😉. A smart fella like yourself should be able to figure a reliable way to stow the rotors when playtime is over. Hanger and apron space is the main reason that teetering rotors with brakes for fore-aft parking have dominated market. With a 3 blade system then there are neat systems to fold all three blades along the tail boom. Obviously the very real risk is that the retaining pins don't get fitted or fall out in flight.
There is the idea of upscaling a quadrotor so that teetering can still provide pitch and roll moments at reduced gee with differential collective pitch. As long as the thing can safely autorotate to the ground in the highly unlikely event of a drive failure 😟. Then the rotor booms could be folded to stow the machine, and the retaining pins more solid and easier to see.
Just my brainstorm...
Ground effect boats or planes are dangerous. Look at how close the wing gets to the water. If you stuff up, or get a wind gust, you are fish food. Fully articulated is the best, and it is not very complicated, that is what I chose after a lot of research and comparison. Look at the MD500 system, or the AS350. Both are quite simple and low maintenance. Designing such a system for a small helicopter is easier. When you spread the load over multiple blades it also becomes easier in my opinion. My design is 6 blades. If you have no intention on flying fast or high, go for a rigid system such as that on a BO105 as its simpler again. The Robinsons were designed to be as cheap as possible, from a mass production with a target market of the low income it must be kept very simple. For one off homemade not so much. The stability alone of a fully articulated rotor outweighs a teetering hinge. I looked at making a model, and a simple helicopter and slowly climb the ladder, but it ends up being more expensive and complicated and time consuming making several versions than just tackling a design that is a little more complex.
I enjoy your humour and videos, best of luck Ben.
Hi John, thanks for the comment, the wing tips of a wig boat coming into contact with the water is a concern but can be protected against. James Greenberger added small sponsons to the trailing edge and I believe has tested the feature. The wig boat idea seems less dangerous than a homemade helicopter but until you experience it I suppose it's difficult to draw conclusions. One of the biggest concerns I had with mine was that driveshaft right behind me, a different design getting that feature further away or incased would have been safer. Lack of any rotor overrun was another potentially dangerous feature. Your helicopter sounds like it will be safer than mine in those respects but fully articulated rotors can experience ground resonance as you will know, which can result in the total destruction of the helicopter. Getting this right is going to be critical to safety and that's before you have even left the ground.
It's difficult to quantify how dangerous something actually is, it comes down to opinion most of the time. I think homemade helicopters can be safe if designed correctly but there will always be risk.
The bo105 is an awesome rotor head
How goes the development on your mini MD500 ?
@@Ben-Dixey I dont see the point in something that doesn't fly, and is less practical than a boat. The sponsons may help, but still. I thought for your heli the best option would be having the engine tilt with the rotors, so no need for a flexible driveshaft. a mechanical or electronic governor could have fixed the engine overrun concern. As for ground resonance, it is a concern and have not overlooked it. Having more rotors that are lighter means they require less movement in lead lag. They are less susceptible to creating an imbalance, although not impossible. Most of the resonance issues is with 3 heavy rotors. It is untested so far and complicated, but there are many factors that induce resonance, mass, rpm, drag, the range of movement that occurs and that is permitted. For test flight I will remove the lead lag dampers on rotors so that there is no chance of an imbalance occurring. For testing and hovering this will be acceptable, it is only in forward flight that lead lag is really required. I will have dampers on the landing gear, plus I intend to have a wheel dolly or larger skids under the landing gear for first flight so that it can move freely side to side. I do intend to make pontoons/floats also, so could even use the lagoons on the farm as a shock absorber.
My project is slowly going. Working on transmission and doing oil testing. Stuck on what dash to use, so many options, You can spend 5-20-k on a screen alone, I want to choose the right one. I procrastinate and then a new model or product comes out, far out. I still have a lot to do, still have to make a pressure suit for high altitude and hope that it doesn't pop, lol. its all fun, thats the main thing.
Sounds good to me and that is the main point, having fun. You can't get much more excitement than designing, building and testing a homebuilt helicopter. The point of the ground effect boat is primarily to have fun and low to the ground is where I think the most fun can be had. My helicopter was only intended for hovering but a achieving just that isn't easy.
I suspect it's a good idea to test yours without the dampers as long as the wind is calm. A head wind will give the same scenario as forward flight.
How do you go about balancing multi bladed rotors ? Not something I've considered.
@@Ben-Dixey From my understanding, at least here in Australia is a ground effect boat only requires a boat licence, so cost is saved there.
All flight tests will be conducted in the early hours of the morning. 2-4am is usually very calm. I have thought of that. Dampers are to reduce the stresses applied to the rotors to prevent fatigue damage, and this is an occurrence at higher speed. For short term, it is not an issue.
As for balancing, it is not all that different from a rigid or semi rigid. The overall weight and centre of balance must be the same. For tracking balance, the rotors have a trim tab fixed to the blade so you can make them all rotate on the same axis by bending it slightly up or down. I have not made my rotors yet, but intend to make a few more for stress testing. I have designed the rotor head to accommodate small cameras that will be able to overwatch each rotor on a screen in the cockpit for tracking and movement. I keep thinking of ways to add complexity. We have so much technology and products available to the average person now, it makes possibilities so much easier. Off topic now, but little cameras I think are great, you can have them pointing in all directions, in the engine compartment, looking beneath, watching the tail boom. One of my concerns is pulling hard rearward on the cyclic and having the rotor hit the tail. By having cameras I can see how close it gets. After I am confident with a hover, I was thinking of making a mock up cockpit and using radio control and fpv for more adventurous testing. I do worry, I will be over excited and try and fly fast too quickly. I figure Ill just chase kangaroos around for the first few hundred hours.
Anyway, enough from me.
th-cam.com/video/gyLwK7Akx2I/w-d-xo.html
give some thort to par thrust for initial lift at low ground speed .. im putting the big motor cycle engine at the cg and a long propshaft to a cv joint and thrust bearing steering knuckle to tilt the prop up a tad at takeoff . and yes my cv boots r holding up at 2000 rpm on a test bed .. motorbike sprocket to driveshaft adaptor from kit cars .. takeoff in 2nd .. shift to 3rd for cruise . .. jeeeez what a wanker i am
Thanks 👍 Par thrust is a smart addition I think, I don't know if there are any drawbacks to it other than the more complicated drive systems. What stage are you at with your build ?
@@Ben-Dixey iv done a full size mockup in cheap plywood that becomes paturns for a stitch and glue boat with wings
and worked out all the machanical drive train stuff on a test bench ,, thats done . thin marine ply and epoxy next oh joy . im a steel boat man . and epoxy tries my patience oh .. the canard is pitch control btw and having the engine inside is less drag . and lower cg ..i love james wings nice and simple easey to extend
also built a 3meter r c model to test P A R thrust .and fully flying canard . its very effective .. jumps off the water . . water is very sticky and draggy and hard when hit at speed and much bumpeyer than an air strip
Underslung rotor systems are inherently dangerous. R-22's crash regularly from negative g's. Many a video of people dying from the tail boom being chopped off mid flight. I would not even ride in one myself, but pick your poison carefully. 3 blades at the least. 2 blade rotors are not a fun ride at speed. Notice the cyclic of any video when in a Robinson. The shaking is abysmal. The stresses of those system take their toll overall pretty quickly. Rotor inertia in a Robinson is terrible. JetRangers are better but look at the mass of those blades. The ride in a JetRanger is awful at speed.
Are you speaking from experience or just parroting what you've heard in comments?
All of my flight hours are in Robinsons, and your comment is extremely disingenuous. Firstly, low-G pushover IS a dangerous condition for any 2 blade rotor system, but Robinson's don't crash "regularly" because of this. In fact, mast bumping makes up a small percentage of Robinson accidents. A vast majority of Robinson accidents are due to power management (or lack thereof) and striking obstructions like power lines. For how many Robbies are airborne, mast bumping is extremely rare. Furthermore, it is a condition that can (and does) happen in other 2 bladed rotor systems, there's just more Robbies in the air than all the other 2 bladed birds combined, so you see it more often.
Also, the cyclic on Robinsons does not vibrate violently, at least not on a properly balanced one. You may be confusing deliberate inputs with vibration, as the R22 requires a lot of cyclic input at a hover, particularly in windy conditions, because of how "twitchy" the bird is. Hovering a R22 is a very engaging process. The R44, on the other hand, has zero vibration and rarely requires more input than some pressure on the cyclic unless you're doing something rowdy like wrangling cattle.
I dunno man. Your comment just reeks of someone who has never sat in a Robinson and is just talking out of their ass after watching the R44 Cadet crash that happened in Texas last year.
@@Maverickib As you have never flown anything but Robbies I can assure you that you are biased. 50 hours of factory certified training was required by the FAA and insurers when they were killing people pretty regularly at the beginning. Why? Bad design that was certified by idiots at the FAA.
That rotor system was developed from autogyro systems. Boosted hydraulics are always smoother, but another failure point. Load up an R-22 at max gross on a hot day and do me a hovering auto from 10 feet. Inertia in that rotor system is abysmal.
How many full touchdown autos have you done? I did over a 100 in my initial training. I used to teach full touchdown autos. H300's and JetRangers. I've had 5 engine failures, 1 from hover. Never bent a helicopter or damaged one in 4000 hours of flying.
If you gave me a Robbie I wouldn't do anything with it but hope to sell it. The cyclic setup is comical just in itself. Obviously you're a bit butthurt over my comment, but I stand by my 45 years experience.
Good luck with your choice, but I'm not a fan of Robbies. They became popular because they are simple and cheap to make. The only commercial operators are training, cow scaring and sightseeing for a reason. Cheap.
Nobody is going to hire you with just Robbie experience except Robbie operators. Try getting HEMS or Commercial ride with that as your resume. Not going to happen. 100 hours of Astar or 407 time would be a better bet.
The Military owns zero Robbies in the USA. Cheap and twitchy. When starting an R-22 they look like a mule crapping sandspurs they shake so bad. Not good for any drive components lifespan, and if I was uninformed would probably not know the difference. Cheap way out and didn't conflict with standing patented systems.
My advice would be fly something with more than 2 blades and see the difference for yourself.
Fly safe.
its pretty simple get it right or die
Sir you dont no necharial
Sorry sir , think think think and only think
What are you trying to say ?