Dodgy Moment, Homemade Coaxial Helicopter Learning to FLY
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- Опубликовано: 29 сен 2024
- An uncomfortable moment in this video where my extended skids luckily do their job.
After a lot comments, the machine is only intended for low altitude hovering no higher than 6ft or so. In the current configuration it wouldn't be safe any higher, I could add measures to change this but no intention to do so at the moment. The machine is tethered in all tests but they are long enough not to present a danger to myself. 
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It appears that you are giving input to the pedals with your whole leg. This will result in large pilot induced inputs to your cyclic because the height of your knee will keep changing. You should be pivoting at the ankle and inputting with toes only. You heels need to be supported and stationary if they are not now.
Great observation. I will see if I can alter this, I would have to increase the ratio of pedal movement to fin deflection but I think this would be a good idea anyway. I'm moving the pedals way more than a Robinson.
Oh wow, great obs! You may have just saved this guy's life. No kidding! Cramping could occur with the set-up, too, and a charlie horse is not a good thing while flying this!
Whilst I agree it is difficult to prevent unintended pedal inputs if the heal doesn’t have a rest, rudder pedals are connected to each other in opposite sense. Any motion imparted to the foot due to the knee moving vertically will apply to both legs. As you can’t push both rudder pedals at the same time, this shouldn’t be an issue. I can see the benefit of using the knee pad to steady the right arm though, although if this is necessary to be able to fly I think you have a bigger problem to solve.
@@gillfitzpatrick7894 I am not sure the reason you have brought up both legs and counter-operating pedals. But yes, an push input from the left leg WILL impart a right pedal push on the right leg causing a cyclic input. What is the bigger problem you have mentioned?
Gotta accept the lag, especially when torque controls yaw, not ona the tail boom parasites. 👍
It's the damn RUST MINI!
Your Mother never told you that if we were meant to fly we'd be born with wings did she.
Why are you screwing with Physics - you can learn all you need to know about Flight by picking up a rock and dropping it 😂
Loved the video and have watched a few to know the work you put into the counter-rotating Anti- Ejector Seat device.
3:45 for dodgy moment
To increase safety I would consider bolting plastic balls to the end of your landing gear outriggers. This will help prevent a dig in if you a forced to land with sideways motion. Spherical toilet cistern balls might do it. Good effort so far.👍
Thanks for this, I hadn't thought of cistern balls, good idea. Light weight and cheap. Will think about how to mount them so they don't come off. Cheers
While I agree that the outrigger tips could pose a problem, I was thinking that the outriggers need not be level with the base of the copter. If the outrigger tips were raised up by 5 to 10 degrees from the base, they would be much less prone to digging in from slight angle sideways helicopter motions, but could still protect against very high angle tipovers.
That’s the exact same things I used when I was learning to fly a model heli
@@kitchencone Yeah, but having stabby things pointing up isn't a great idea
@@mikejj101 Yep same here, definitely helps to prevent dig ins, which in a model RC copter is extremely costly (certainly back when i was doing it), where as in real life could be deadly.
Wind sock evidence seems to suggest that lateral movement was probably caused by a gust BUT - perhaps not. Depending on what the TRUE root cause was for that roll . . . . your decision to land immediately MAY have saved the day. Until you are certain of the root cause, I am tentative about your thought to push it harder next time. 1000 Hours in the air in hang and paragliders - - - I've always been rewarded with a decision to get out of the air when conditions were deemed too treacherous or UNCERTAIN. The decision to "push further" was only made when conditions and attitude were as anticipated and fully understood - irrespective of how I might"feel". There's a difference between experiencing (for example) high G's for the first time and "pushing" through it - - - and pushing harder into an uncertain regime.
I have read about the situations in which you speak of and I can understand your reason for mentioning it. I guess it depends on whether I could have rescued the situation or made it a lot worse. I have had smaller instances of this where I rescued it and didn't try landing travelling sideways. I think I would have rescued the roll back to a controlled hover on this occasion had I not descended. I suppose it's about judging your own levels of competence but in a split second. This time all was ok but it was dodgy. I'm not going to fly in wind that gusty until a greater level of ability has been achieved.
Good morning. I am enjoying watching your progress. I do have a few questions/suggestions/observations for your consideration.
1 MARK THE LIMIT/RADIUS OF YOUR TETHER. Painted circle or tufts of surveyors tape on pins. Movable and re-usable. There is a danger of reaching the end of your tether and causing you to fight against it in a recovery. I have seen a number of videos with a tethered helo that would have safely flown away get destroyed due to being tethered. 2 CAN YOU ADJUST THE SENSITIVITY OF YOUR CONTROL STICK? I know there is only so much space between your knees. But a small amount of stick input seems to upset your helo. 3 WIND SHELTER. I under stand the logic of hiding behind the tree and fence line, however the wind turbulence behind the wind break may be more harm than benefit. You may really be better off in an open field with straight and consist wind patterns. I know good days to fly are few but if 5 mph is your safe limit then obey that until your skills improve. 4 CAN THE HELO REMAIN STEADY WITHOUT INPUT. Is the mast head in balance? Are you constantly having to provide correction to the helo? Is there any vibration? Have or can you pitch track your rotor(s)? 5 DO YOU HAVE THE SKILLS TO FLY A HELO? I know that as I have aged (60) I do not do things as well as when I was younger. It is one thing to learn a new skill and strive to do something new. Is it worth dying for? Professionals crash helo's on a regular basis. I watch Dan Gryder Probable Cause on RUclips. In the USA we are loosing one General Aviation aircraft a day this year. He has a great channel. Lots to learn. STAY SAFE. Regards Dudley
Thanks for the input. The marked circle would be an excellent idea, it's easy to loose track of how far you have moved. The tether going tight would be disastrous. Given the choice I would ditch it but I can't do that. The tethers are 100ft long so I would have to go half way across the field for them to get tight but certainly good to mark where that is. I did reduce the sensitivity slightly of the controls previously but my thoughts are now that it needs to be more sensitive, more like the R22 I had a lesson in. The cyclic on that was twice as sensitive to mine I would say. I think less travel on the cyclic would mean faster corrections making it easier to keep up but I could be wrong, it's difficult to say what is for the best.
@@Ben-Dixey Thank you for the reply. My observation on the control input is limited to what you post in your videos. The R22 sensitivity may be a function/need of the rotor system. Stay Safe. My helo experience is very limited, but I recall the pilots did not have to have input to the controls at power just before flight/lift off. IE the rotor seemed to be balanced.
hello mate, may I suggest pointing your nose into the wind, increases the wind-cocking effect and stabilizes an IGE hover. Please also extend the front and rear skids, or extend the bent up ends to avoid a dynamic rollover. Also, would pay to maybe get one or 2 hours in a Robinson r22 to learn the basics of helicopter control as it is the most unstable helicopter out there. aside from that decent hovering, have seen worse in real helicopters in people with 10hours
Hi and thanks for input, great thoughts. Interesting to know that the R22 is the most unstable bird out there. In the previous video I did some training in an R22 it was a great experience and plan to do more.
Good morning from Washington state USA, you get better keep up Good control.👍👍🙏🙏
I think the natural instinct to bring it down is the correct action for a novice pilot in a homemade helicopter. Anyway good to see everything is fine and ready to proceed without any issues. Congratulations on your achievement so far.
Man watching this there are only two outcomes. You fly successfully or you get hurt bad. There is no in between.
I would recommend a heavy cable or chain directly under the C of G to calm pitch and roll down a bit, similar to an early Lama R.C. umbilical chord model.
I have never seen a more terrifying title for a video. You have earned a subscriber. Please don't die building this machine!!!!
I’m not going to pretend to know anything about the intricacies of a machine like this, but be careful.
I'm starting the build of a Hexacopter manned drone and, even though our projects are completely different, I'm getting a lot of inspiration from you. Congratulations!
Sounds Interesting, are you going electric ? I would like a manned drone.
@@Ben-Dixey Yes, electric. I'm still thinking about making a channel on youtube or not, but if you are interested I would be glad to share the progress with you.
@@flaviovianna4889 Make a channel on YT! I’d love to watch your progress! If you’re inventing new tech though, I could see why you’d want to keep it private.
lols I help develop the best racing drone software available and fly racing drones and.. NO THANK YOU... unless you like human sushi 🤔
@@flaviovianna4889 Yes I would be interested for sure. btdixey@hotmail.com or YT channel would be great
Good job! It looks so stable compared to earlier videos. I like how you take everything into account and have safety first. Looking forward to the next video. As Scott Manley always says: fly safe!
That was a bit scary. I can only imagine how you were feeling at that time. Really enjoying the video and seeing your progress, safety always.
Thank you. Yes it wasn't nice and was a wake up call to what can happen but I think next time I won't reduce the power, that was my mistake.
Not a real Helicopter pilot however I fly RC Helicopters, when hovering close to the ground you have ground effects. In Ground Effect (IGE) is a condition where the downwash of air from the main rotor is able to react with a hard surface (the ground), and give a useful reaction to the helicopter in the form of more lift force available with less engine power required. When I first started learning I had a dude tell me get higher up away from the ground effects and it's much easer for hovering.
Thanks and yes I have felt the difference in stability higher up, when I'm feeling confident I will increase altitude but haven't been any higher than 3 ft to date. It takes some nerve to go higher and it will gradually increase as confidence does. It's the old catch 22 you need to go higher to make it easier to learn but you need a higher level of skill to advance to higher altitudes . Dual instruction is the easiest and safest way
@@Ben-Dixey Once you've gained the confidence everything will fall in place, you will fly higher and start going places. I fly a Cessna 172 IRL and it took me about a year till it all fell into place. I look forward to more videos.
When you said "The grass is shorter now..." I thought it was going to a SUPER dodgy moment where the helicopter mows the lawn
😆 no thankfully not that dodgy.
Bell 47 has the radiator immediately behind the cab, between the cab and the engine. There is no airflow induced by the rotors there. There is a shroud which forces the fan driven air through the radiator, it cannot escape out the sides. I would start with that, minor alteration and virtually no weight gain. Was the Robinson time hovering of assistance? Love your friends reaction.
Good plan, thank you 👍 as you say the shroud is virtually free cooling improvement and easy to install.
The R22 did help in a similar way flying at home does but with 20minutes hovering in the R22 that is more like two days flying at home because I can only do 1 minute 20 at a time. I might do 10 runs in a day if I'm lucky. What was really great was to reacquaint myself with the sensitivity of the 22 and compare it with the coaxial. As a result I'm going to make some of the controls more sensitive. The instructor was also great pointing out things I can Improve on. Him telling me I was behind the helicopter and needed to speed up the corrections was super, it's not something I wound figure out for myself very quickly.
Part 8: From one professional mechanical engineer to another... you could [still] shave 6 months off your product development cycle time by using an electric motor. For shorter tests - you won't even need a battery. Overall though, excellent work!!! Great videos!!! (just envision... no more metallurgy, "should I use a new steel alloy", HP vs. power responsiveness rabbit holes, bearings, cooling pumps, vibrations, lubrication, fuel management, rpm/torque control concerns and about 50-100 more things) Electric motors are 99% mechanical engineering anyway - only those pesky, invisible things like electrons and magnetic fields are EE, Lol. Huge congrats on overall work!
Hi, and thanks for the comment. As you say it would have been so much easier with electric motors, I could have had two motors spinning in opposite directions which would have simplified the rotor reversing add into that yaw control via differential rotor speed. ( no tail vanes required ). plus all the things you mentioned. It did of course cross my mind in the beginning, there were two things stopping me cost and flight time. The electric setup was way too much money for someone who didn't know if they could even build a helicopter that could fly. It's something I would seriously consider for the future but it's still very expensive, I suspect in time the cost will come down or there will be other second hand vehicles you could buy and utilize the components.
@@Ben-Dixey Hi, and great to hear back from you. The rationale of flight time is right on. However, I didn't realize that electric motors and peripherals were more costly? I may try to contact a coaxial builder, there's are a couple in southwest Ohio, near me. There were a couple of fixed wing guys from this area, but that was a hundred years ago or so. Not sure if the family is still into it.
@@stevieathome4942 Yes, I priced up the battery's at the time which came to £10k. I'm sure they are much cheaper now and better performing for there weight. Pascal Chretien built an electric version quite a while ago. seemed to work well.
Very interesting form for a randomised suicide machine!
Most impressive. 10/10.
Isn't that called the compliment sandwich ?
Collective is about mass. It can be changed very quickly, but the whole head can’t move that quick. It’s like live axel vs independent suspension. Equally, I thought it flew very well :o) it’s going to be jumpy when the whol thing is so light.
I expected the same, I thought the movement of the mast would be hard and slow and I might even need hydraulics. However it's incredibly light in flight, almost as light and responsive as a Robinson. Not quite the same but very similar. Not what I expected at all.
Geezer really made a little copter, hats off to you sir!
From the look of your field and where you are situated, it is possible you are in a turbulent area with that wind direction.
Not sure what terrain causes turbulent air, we are around the top of rolling hillside with a sea view. I'd say it was generally turbulent air at a guess.
Love what you've done with the skids. Smart to go that large when testing (or even later). I would probably consider making the curved tips a bit bigger: you're not far from getting a tip stuck in the ground in this video.
Thanks. I've just added plastic balls to the bent up ends and have just tried it. Think I'm happier with more clearance. I could bend up the ends a bit more anyway, it wouldn't hurt.
@@Ben-Dixey If you look at it like a machine made to skid, then I would say that a long progressive curve would be ideal (reduced friction) much like the shape of modern skis (rocker), which is also more or less what a lot of helicopters are equipped with. Even better would be to cover the bottom with PTFE or polyethylene but that's pushing a bit :) Amazing effort anyway.
Hovering is critical, but 1) having in mind what you intend to do prior to going airborn is important, and 2) you'll find greater confidence and characteristics once in forward flight.
How would you Rig an Ejector Seat on that?
In the early wars, they timed the gun shot to miss the propeller so can we see your intended design for your Ejector Seat please? I'm Kidding ok - the aircraft design looks doable but with big sail of 2 blades that wind is going to be there and you can't bring them closer together due to touching like the Roberson.
4:10 that could be causing deformation or work hardening and if it's that bad probably with normal use
You are adding to your learning by trying to fly while in the ground effect. Get out of the ground effect and you will actually be able to learn to fly.
👍 It's catch 22, but yes I'm aware of the situation.
It would be easier to fly if you were sitting more upright than lying down like this.
Hovering in the gound effect is much harder, looks good tho, respect
The wide skids are flexing, but have worked correctly when required. Congratulations on going back up!
Yes thankfully they worked well, no way I could have even got this far without them. In time I will gradually reduce the length but certainly not yet. 👌
DO YOU HAVE A PILOTS LICENCE? NOT LIKING THE CONCEPT OF LEARNING TO FLY NEAR POWER LINES.
No I don't have a licence. The helicopter doesn't have the performance at the current blade pitch to go higher than around 3ft. You would also have to be flying above the hedge. No worries at the moment but when higher altitudes are achieved I will move further into the field away from the lines.
that looks like a helluva great way to get to the line of way too sketchy and way too fun, what an cool way to spend your time and effort, love it!
Absolutely well done!!! It's great to see a true helicopter without all the highly complex swash plate systems. Looking farward to your next flight!!
OMG... reminds me of learning to fly RC helis back in the 80's... same wide landing gear, same tentative hovering. Only I wasn't in it!
😉 It's surprising the similarities between RC and full scale. but yes being in it is definitely different.
@@Ben-Dixey Yes... I hopped into a Schweitzer 269 and was flying it completely within 10 minutes. I could even hover in ground effect. The instructor wasn't fooled... "You fly RC, don't you?" :) TOO expensive for fun flight, though.
You are obviously one of those rare naturally gifted people who can just do it. I fly RC and didn't pick up flying the real thing anything like you describe, it''s taken a long time but I have no doubt the RC experience helped. As you know the cyclic movements are very similar but recognizing the aircraft attitude looking out the window is something different. On the plus side controls on the full scale are never reversed.
Good luck hope you don't get hurt looks like your getting there.
Glad you've progressed this far 🙂 I would suggest bending the cyclic back about 10 degrees, so your hand and arm can be more relaxed. For the best control, you should be able to control the cyclic by your thumb and index finger - ONLY. Gentle movements are best. If you 'think' about moving in a specific direction, your hand will automatically move, slightly, in that direction. Currently, you're still 'over-controlling' the craft. Gentle inputs are required. Again, Great Work! 🙂
Thanks for you're input. 👍👌
I'm going to subscribe to see how you progress.
Your rotor mast is bending too… be careful.
Amazing! Just wondering if the slight flexing in the area of the assembly above the cabin is expected, or if the mounting may not quite be rigid enough? Could add a bit of unpredictability to the behaviour of the craft?
Thanks. When you say flexing, are you aware the rotors tilt on hinges? It's not like other helicopters in how it's controlled.
Much improved flying!
It almost seems like you don't have enough power or it's just too heavy have you tested to see how much lifting Force the helicopter is capable of at full throttle/pitch?
Yeah I think as far as gauging your fan efficiency versus horsepower laws versus lift a simple way to connect a force gauge to the ground and try to take off at maximum power would be a great simple way to verify changes
Hi, i haven't tried full throttle on the new blade pitch setting yet so don't know how high it can now climb. I don't know what pitch setting is going to give the most lift either but I'm expecting 7 degrees will be somewhere close. Currently bottom rotor is 6.5 and top rotor is 5.5 degrees. Take off weight is around 250kg and the expected mtow is around 300kg, comparing other coaxial's.
Yes is could be done and it would be nice to know some figures.
Well done so far! Don't kill yourself please! :3
What could possibly go wrong 🥺
I always find it interesting that heli pilots have to learn to do the most difficult and scary thing first. Hover in ground effect, which is by far the least stable condition.
Generally forward flight in any rotorcraft is easier, more stable, and uses less power, but yes you gotta stop, or at least slow to land. Do keep in mind that if you learn to "hover" with a constant headwind, you're not really learning to hover. You're just flying forward at the wind speed.
Makes perfect sense to me, in the next video I experience this constant head wind stabilising effect. I would like to try it in a wind tunnel.
There are many things you shouldn't make at home. Insulin, explosives, guns, your own parachute, and HELICOPTERS!! Jeeze.
Whether you should or shouldn't depends entirely on the person. If it was a new invention you wouldn't be saying that. What if this leads to something new?
So I'm thinking about a possible side effect of directly pushing the rotors off angle, versus using cyclic.
With cyclic, aerodynamic forces change the rotor angle immediately without a counter-force on the aircraft body. The rotors fly themselves into their new orientation, and the body only reacts to the change in thrust angle.
But you're directly pushing the rotors off angle, and while they may counter each other's precession, you still have inertia to overcome so as you push them off angle one way there is an immediate counter-force applied to the aircraft.
e.g. In order to quickly tilt the rotors to the right, there must be a reactive force on the body, tilting it a little to the left.
But what happens when you stop pushing on the rotor and hold the stick in its new position? Gravity will pull the aircraft body back straight down and unless you counter that on the stick, it'll cause the rotor to tilt a little more to the right, which is then followed by more tilt to the right as the thrust line starts pulling on the top of the aircraft, so a little commanded right, becomes a little more right, and then a little more right, which is a bit of a positive feedback loop.
Let's go back to the cyclic heli for a sec.
If you're level, and you quickly tilt the rotor to the right, the body initially stays vertical, then as the thrust angle changes, and starts to pull the the top of the aircraft right, it'll cause the aircraft body to lean a little bit right, but then gravity will try to pull it down straight again (causing a little left rotation), and if you hold the stick still, that will cause the rotor angle
to also return back a little left, which is a negative feedback condition.
I suspect the difference is subtle, but most noticeable while trying to hover in turbulent conditions.
My hypothesis is that you may need to think about giving a command and then taking it back a little bit (moreso even than you would with a normal cyclic heli).
Very Interesting comment and I'm going to have to think about what's been said. There is one bit of information I would like to add, I believe aerodynamic forces help to tilt the rotor by cyclic angle of attack changes. The same as a gyrocopter where moving the cyclic is very easy. The difference with my coaxial is the top rotor being so far away from the hinge. This means some force will be needed to move the rotor laterally which causes the airframe to tilt as you mentioned. I can feel the cyclic stick wanting to return to centre after an input which I think confirms that some weight shift is indeed going on.
the top section of your coax-heli is so damn "wobbly".....when you hit the grass and do skid sidewards = kind of scary to me..... = whow..... ! ! // second: I am happy that you are no foul and you do judge your actuell skills very well / thanks for sharing the video
Later in the video I show that the whole rotor mast tilts on hinges for control, it's not like any other helicopter you would have seen.
These are rather hefty pilot induced oscillations. You aren't making it easy for yourself. You are starting out trying to learn one of the most difficult maneuvers, the hover. Most of us who fly were building up proficiency on fixed wings, prior to rotary conversion. And it was bloody difficult getting the hang of the hover.
Try a different approach. Get your rig on a huge, level field. Get your rig moving straight ahead, while dragging your skids gently along the surface. Build up confidence and speed. At a point, the ground effect will gently lift you off the ground. Which is the sketchy point in this strategy, because now you'll have to quickly learn how to set down safely. Better to take some lessons with an instructor now you've established your helo works just fine. 😉
-That will give you time to redesign your rotorheads. They aren't safe at all. When you get flying, the slightest mast bump will eject your rotor blades. Don't keep those widow makers!
Appreciate your input, it has been suggested once before about sliding along the grass to produce some stability Increasing translational lift. I will give it some thought. Bare in mind that the total stick time with a helicopter is probably less than 2hrs and I feel the extended poles are safe to continue in winds less than 15mph As you say I haven't any fixed wing experience behind me which would be of benefit. I might do some more R22 training, I'm not apposed to that.
The mast bumping I do have teeter stops to prevent the blade straps coming into contact with the mast. I didn't think you could get mast bumping unless the rotor is unloaded or taking off from an incline and I think you would need cyclic blade feathering, remember I'm tilting the mast where as most helicopters tilt the rotor and the mast stays still. Please correct me if I'm wrong.
You spoke of anti-torque pedals, but since an advantage of coaxial is that the torque from one set of rotors counters the torque produced by the second set of rotors, do you, really, need anti-torque? Seems that in your case your heli has a rudder not anti-torque.
Absolutely right yes, my pedals aren't anti torque and should be called rudder or yaw controls. 👍
@@Ben-Dixey Yaw control... that covers it all. :-)
I litteraly had dreams as a child of building a helicopter from a scrapyard and feeling so free whilst piloting it. Still looks unreal :)
Looked like it is very sensitive to stick inputs and difficult to smoothly change or hold position. Would a dampening system help there? Like a 2, 3, or 4 way set of model shocks or other small and light dampener? There are probably better ways but my suggestion seemed simple and cheap to try if it helps or not.
On a side note I really want to learn para-motoring but finding anyone in my area that isn't booked out to 2024+ seems impossible.
Hi. A few people have suggested this, I personally think that the control needs to relatively free and undamped. However some helicopters have cyclic friction, whether it's used in hovering I don't know.
Shame about the paramotoring, seems similar with heli lessons, they are still trying to catch up from covid, meanwhile instructors have left the business of teaching.
I don't know for how long you're flying helicopters. But i think your inputs are just too much. My FI always told me to input the smallest amount of controls when hovering. Moving the stick too much causes unbalanced hovering.
Yes it's been hard trying not to over control.
You need to adjust your seat/pedals so that your leg is higher,,,,,,, or shorten the stick,,,,,, you want a resting point of your right arm on your right leg,,,,, most flying done with wrist movement
👍 I'm going to shorten the stick. It's too long anyway. I'm also going to increase the sensitivity of the yaw pedals so that leg movement is reduced.
This is the fist video of yours I've seen an this could be something you've already tried, but have you considered putting actual dampers on the pitch/roll stick and/or what it connects to on the head? I kind of also wonder how much slop there is in the control stick and if that's a problem. Dampers with a spring return might take the load off of you having to manually hold it steady. I know all of that adds weight but it shouldn't add much complexity or cost.
Hi. Yes dampers have been suggested I'm not convinced they are the right thing to add. There is a tiny bit of play in the controls which I would like to get rid of. The problem is the pilot at the moment, just need more practise and more flight time would help that. I might increase the sensitivity of the cyclic as I'm having to move it much more than an R22 but not sure on that at the moment
Learning to fly RC helicopters in the early 90's cost me a whole lot of money because wrecked em almost every single time they came off the ground so watching you do that while sitting in the actual egg beater with seamingly no protection terrifies me to no end. You are so much braver than I, that's for sure.
You seem level headed though so I'm sure you'll figure it out and be flying that thing around like a Ferrari in little time.
One suggestion though if I may? Some round balls at the end of your trainers so that the risk of them digging in and rolling over would be reduced.
Just looking at purchasing some balls. The ends of the tubes are bent up though.
US Army Helicopter aviator says... "Study dynamic rollover".
Those long outriggers scare me.
So far they have prevented a few dynamic roll overs. I think as long as they can't dig in they are the safe. Dual instruction is even safer though.
If you face the wind sock? Maybe you could have more info on what’s happening?
I think that would be a good idea. 👍
You should you using fingertips on stick, and literally moving your toes for adjustments.
👍 can't disagree
Loss of position is not loss of control.
I'm not a helicopter pilot, but I worked for Mike Hynes, Brantly Helicopter, as a machinist, and all the pictures and movies of B2 test show Frank Erickson filing chained to the ground. There was no question about Frank's ability to fly helicopters. He had been doing this as long as anyone. The wind or whirlwind in Frederick, Oklahoma, could wad up a B2 in seconds.
Hovering that close to the ground is dangerous. No one has fast enough reflexes to counteract errors and accidents that happen that fast. Tie your rig down on short chains so your skids don't dig in, and stick your rotors & head in the dirt. At least bend the ends of the skids up and put aluminum balls on the ends of them.
I don't think the actions of a rigidly mounted helicopter rotor with conventional cyclic and collective controls apply to rigid counter-rotating blades on a tilting shaft.
Good Luck!
Hi, Good to hear from someone who made Brantly parts, I don't know a lot about them apart from the ice cream cone shaped fuselage. After a bit of research it seems a well respected and made machine. Great sound from watching some YT videos. I like the three bladed design, high inertia rotor system for good autorotation and smoother ride.
I agree about the dangers of hovering close to the ground hence the reason for the long poles which do have the ends bent up to prevent them digging in. Balls on the end I'm open to.
I started off with short tethers to ground anchors and they were needed in the beginning. After gradually extending their length they were starting to be a hazard and preventing the process of learning to hover. I still have them now but they are 100ft long and serve no purpose other than allowing me to show the videos. The 5m long poles have been great at gradually allowing me to gain altitude in safety and learn the skill of hovering. I guess now I'm getting to higher altitudes (3ft) things have the potential for rougher harder landings if things get out of control. The rough landing in the clip has been the worst over the last 6 months testing and it's also been the windiest conditions I have dared test in. Back to calm conditions for me now.
With wind you WILL get turbulence from the hedge and the trees even if you dont think they that close!!!
👍 I'm beginning to realise this, interesting stuff.
If you have a tilting mass it will be less responsive for larger helicopters. For your small heli it is manageable but when it comes to something with more carrying capacilty and something that needs to be more responsive then tilting the mass of something that may be more that a tonne in weight may be problematic. This may also be a problem on smaller helis as a heli isn't the most stable aircraft.
I can see the logic. I did expect mine to be much less responsive than an R22 for example and I was surprised by how responsive mine was. I still think the R22 is more sensitive on the cyclic, the cyclic control ratios are different between the two machines and I feel mine should be altered to make control inputs smaller. I personally think a larger rotor would react fast enough to be controlled as it's the aerodynamics that provides most of the power to tilt the disc not the pilot.
I think the most dodgiest of dodgy flying things is a helicopter. Building one yourself must be the dodgiest of dodgies.
So far there has been no suggestion of click bait in the title. Hopefully the video was described appropriately. 😉
Cool video.... You issue with the wind induced stability/control issues is the fact that you are flying in rotor! Why would you fly directly behind and so close to the tall hedges and trees upwind of you? No wonder the windsock is shifting through 90 degrees like a mad man.. Go fly in the same wind speed in a big open area and i garantee you have a better time of it
Thanks for the advice and I agree it would be good to find somewhere open and away from obstructions. Not impossible just inconvenient. The realisation that hedges and trees ect cause turbulent air is new to me but it's good to experience the effect. Calm days would be my preference in the field in use but I have briefly experienced the stability increase with a smooth breeze.
If that was a truly a cold start to full power in a short period of time as it appeared, I'd say you're looking at engine problems in the near future.
No, I warm up the engine on the first run, then the water temp is 40-50degrees before each test run.
I would be cautious reading too much into what the windsock is doing when the air is churning over obstacles in anything but a light breeze.
Ok 👍
Вы молодец у вас получилось. не думали поставить электронный гироскоп для удержания горизонта.
Thanks, I wanted to learn the skill of piloting but electric flight controls could be an interesting future addition.
Need more rotational speed from the blades but the motor is over revving.
An increased final drive ratio on those blades might help.
The engine is at 5500rpm , operational range of the engine is 5500-6500rpm. I can add more pitch to the blades for more lift.
oh... interesting design.
i wonder if there are also intermeshnig rotor home made helicopters
Yep.
ruclips.net/video/9TUbR5Zogv8/видео.htmlsi=qL2K0Qiow95U87Gr
Dick is an engineering genius
One thought, maybe alter your seating position to either a more up position, or a more lay down position. An inevitable hard landing could easily shatter your spine... At the very least add as large a foam/styrofoam block between the seat and ground/skids.
Something to think about 👍
I wonder whether the flight is unstable in large part due to complete lack of computer assistance?
You wonder correct. 🙂
Flying is really something else
A shorter stick would help a lot. Kinda sucks flying in ground effect too..
I think you're right I plan to reduce the stick length. 👍 ground effect isn't helping
Just curious about how much this cost, an xe helicopter is about 46k so how much have you saved
Hi, I've spent £6k building this so far. luckily I bought all the aluminium before the price went silly. To do it again now may cost £10k. This machine will never have the capability of the xe so can't really be compared. A cheaper alternative would be to find an old mini 500, that could be used just for hovering like mine is Intended. For me it was as much about the building as learning to hover, with that experience being valued. To be able to fly properly in the uk the cheapest available option would be a used Rotorway. I don't really have much aspiration to get a pilot license or fly above a few feet, it was just about having fun in a field.
Morning has less wind as we know
I thought that they say that counter rotating helis are easier to fly than single rotor with tail rotor??? I just assumed a novice would have a real easy time to hover and fly it.
Yes I thought the same and I believe it is easier but nowhere near as easy as I thought it was going to be. The hardest control is the cyclic stick and that's no easier than any other helicopter. The other controls are easier than conventional helicopters. I don't have to react to changes in torque and I don't have to maintain engine power. I think the fact that it's small and light weight makes it's more difficult.
You need to look at the end of the paddock and relax on the joystick……zen out and hovering will become second nature for you after some practice.
Thank you 👍
Anyone here remember and get vibes from «Larry Can Fly» from this video ?
I remember watching a couple of them.
Minutes instead of seconds, awesome. You do realise that hovering at one foot is a lot harder than hovering at five feet.
I've been told that and have experienced the difference between 6^ and 3ft I can imagine 5 feet is even better. Going 5ft high takes some nerve at this stage which is why it hasn't been attempted. Assuming that is it has the performance to go that high that is.
bro help yourself and smash some electronics with an easy stabilization software to that
It's possible to add a flight controller but it wouldn't help to achieve my goal of being able to hover a helicopter. Part of the project was to learn the skill, apparently it's as easy as riding a bike once learnt.
ground effect flying always looks like just that , sat on the top of a bubble trying to stay on top
👍
Couldnt you slap on a HOTAS joystick on there just for the cool
I could.
When at a hover, where are you looking? If look farther out, it will help you to not over react and therefore over control.
I'm looking out ahead mostly but I do have the odd occasion where I revert back to looking at the ground. It's much better looking out to the horizon.
Agree that it would have been best to keep it airborne certainly until you’d stopped the lateral drift. This experience will give you the confidence to keep it up. This was almost a rollover crash, but luckily your bars saved the day. After all that’s what they’re for.
I guess panicked pilots do the wrong things. I won't be letting off the throttle next time. Perhaps it can be likened to drifting in a front wheel drive car, the back steps out and if you let off the throttle things get way worse. Keep it pinned and you will be fine, it's just keeping your nerve.
Good build, What degree did you set your fixed pitch blades 4 or 6 degree?
Thanks, the top rotor is set at 5.5 degrees and the bottom rotor is set at 6.5 degrees.
To verify that cooling efficiency is actually the limiting factor here, i guess you can quickly rig a gravity fed water sprinkler on the radiator in order to add a good measure of evaporative cooling to the system. I reckon for a couple minutes of flight time a simple water bottle ziptied to the frame plus a few plastic tubes should simulate a bigger radiator/fan and cooling efficiency should go way up.
Interesting idea, I hadn't thought of that, I don't see why it wouldn't work. I suppose it's like adding some cold water to system?
@btd1982 yeah, should have a similar effect, without having a external system feeding in cold water. It's commonly used to dramatically increase intercooler heat exchanger efficiency, even quick and dirty setups should have a measurable effect ruclips.net/video/ZtUfgA_mtDA/видео.html
@@Ben-Dixey evap cooling works great, highly used on intercoolers.
Great to see you are making positive progress, it wont be too long before you are hovering without thinking about it.
Your power plant will ultimately hold you back in its present form. Take care and thank you for posting
A belt driven helicopter? Hope you have your affairs in order.
Rotorway and mosquito use a belt too.
you are trying to hover in ground effect... down wash you wont learn with that
It's catch 22 but three feet high is definitely better than 6" high. I intend to advance to higher levels asap it just takes some nerve.
Wow the head looks fragile and can snap anytime in half didn't mean to discourage you
Hi The head tilts on hinges for control, it's not like any other helicopter.
Brilliant, just brilliant
What does CFM mean? (Hooray acronyms save time)🤔
Sorry. Cubic feet/minute. Radiator fans output are usually measured in this unit.
How can people put so much trust into an old DIY piston engine?
I trust it enough for a few feet. No more than that and I wouldn't trust a new engine as much as an old one. For the same reason if you buy a new R22 you will find a Lycoming 0-320 engine developed in the 1950s.
well you are still making progress mate 😀 keep at it. when you put it down after the oopsey moment i did notice the mast and the square, is it a gearbox? appearing to articulate and wobble compared to the air frame. Could that be adding some 'deadband' mushyness to to pitch and roll? Coul
pled pendulms etc. just a thought.🙂 Al edit: I see you comment on this, some sort of damping perhaps to slow the double pendulum interfering with control inputs.
Possibly a damper could be added which only took affect in the event of a rough landing. It would have to be fairly free moving otherwise. The R22 has a cyclic friction adjustment to make the control harder to move. I don't think it's necessary but I guess it comes down to pilot preference.
@@Ben-Dixey Well i'm sitting here comfy and 'experting' 😄. Your project BTD, so go where you think you need to eh 😉. Keep up the good work, baby steps n that, you'll get there...
Great save! I think the PIO’s prior to you reducing power put you in that situation. If you had increased the revs, it may have got worse. Hard to say. The shorter grass helped the extended poles slide and not dig in. In regards to the overheating, can you give us some numbers please, we may be able to identify a solution. Does the engine CHT match the temperature of the radiator? Is it the EGT that is more concerning? I’m wondering if an increase in jet size may help. The old rule with 2 strokes is if they ran hot in climb you enlarged the jet to assist with the cooling and to prevent seizure. With your engine under full load you are in the same situation. I look forward to the next video. By the way, the further you are from trees reduces turbulence. Being closer to the windsock may have given you more stable air to fly in.
Thanks Kim, fully willing to accept I caused the roll angle it just seemed to catch be by surprise. The CHT is the temperature on the onboard gauge but I don't have a radiator temperature gauge fitted. I think it would be a good idea to fit one.
I measured the rad temp just after the test with the fan and pump still running. Top of rad 78degrees bottom 72degrees.
I think increasing the jet size could be a good move, but by how much ? Suppose I could take it out by 0.1mm at a time and look at the plugs/test flight duration. I haven't measured any exhaust gas temps. Thanks for the tip on trees causing turbulence didn't know they caused that.
I looked at the general temperatures on a water cooled 2 stroke and I am wondering if your engine has a stuck thermostat. If your CHT is reading high and the radiator around 80-85 degrees either the pump is not doing its job with water flow or there is a impingement in the engine. Can I suggest a couple of things. A water temperature gauge as discussed for the radiator, a dual EGT if you are running two carburettors and for tuning use a Colourtune kit. It is a spark plug with a glass window with accessories so that you can observe the flame colour at all stages of rev range. If you run lean it is obviously white, rich yellow and blue perfect mixture. The kit is inexpensive and so easy to adapt to any engine. I never look at the plug after shutting down the engine as it does not give you any clarity through the complete range, only flat out. I’ve owned a Colourtune for over 30 years and it still never lets me down. My aircraft, boat and vehicles attest to it with reliability and minimal service required. Hope that helps.
@@kimkeam2094 great advice, I have got a colour tune, I've not actually used it on a 2 stroke before, will give it a try and see.
I also agree with mounting the other temp sensors. 👍👍 I took the thermostat out, I know it will need to be reinstalled at a later date.
@@Ben-Dixey As a suggestion put gauges on everything. Monitor everything, Log everything.
At this point you aren't worried about performance. As long as it can get airborne in ground effect and once you get the data you can take them off.
Is the grass shorter because it came into contact with your rotors? 🙂
😉
Our Science channel that yaw part made my blood skip... Man always thought as per other channels it's a matter of build and test but your path is a prove it's not a walk in the park....do you get any sort of permits to do these tests btw?!.
Hi Jeff. Yes I would say teaching yourself to fly a helicopter is as hard as building one. Long poles are a necessity and if the machine didn't have the power to lift the extra 8kg in weight then it would be a no go. We built these machines for a challenge and to learn, this is where the projects don't disappoint. There is a grey area where as long as the helicopter is tethered I think it's ok to test, that's why in all my videos it's tethered but the tethers are long enough not to interfere. Hope you are still making progress 👍
Hi Ben great vid, that last question.....why don't they build helis with the fully tilting head, if someone could answer that ???
Because it would not work. Merely tilting the head relative the fuselage causes a momentary change in the CG but cannot provide a continuous thrust vector. A swashplate causes continuous variation in the pitch of each blade individually and can therefore provide thrust in an arbitrary direction. It is for this reason that, sadly, unless he does a major modification to the rotor head this helicopter will never be able to fly continuously in a direction. It'll only be able to hover (and even then it'll be precarious ) ruclips.net/video/Pu48f7s5Ru8/видео.html
A tilting head rotor system has limits on speed due to drag and inefficient rotor aerodynamics. As a side effect, you are the suspended load and the rotor system is moving around your mass. As the rotor blade makes a revolution, the swash plate on a normal swash plate controlled rotor varies in relation to the forward speed. With no swash plate the blades cannot change pitch and reacts as a drone helicopter blade in forward flight. The cabin pitch down angles would be scary if you had enough power, but drag from the fuselage and rotor blade angles in the airflow would increase the power requirements as well. Racing drones can fly like that, with their huge power to weight ratios. A helicopter that size, it's not possible. Add a swash plate to the system and then the possibilities increase. A lot of people have tried a lot of things. They failed... millions of dollars were spent refining what works. Helicopters are complex for a reason. :D
Grease the underside of your curves of your extended skid tips. Seriously.
Not the flat part, just the curved-up parts.
Good idea 👍👍
Good idea 👍👍