@@Ben-Dixey quick question...per plans blades are 6inch cord(154mm) what would be the consequences if I fitted blades 7inch(178mm) cord... Finding a good blade deal in China...
@@JeffChoppah I don't think it would make a lot of difference in performance, maybe more lift at a slightly lower rpm. You just need to check the blade weight difference. The plans designed blades look pretty heavy to me but you can calculate the weight from the drawings. The rotor hubs should be designed to take way in excess of the centrifugal forces but I would be checking it all for piece of mind. I can help here if you need it. The blade weight and speed will effect the coning angle which changes the teeter undersling but I doubt it be far enough out to cause any issues.
@@Ben-Dixey these conning angle calculations and effects on engine was what was worrying me...the length I can maintain as per plans but cord they have 7inch... building it as shown in plans is cumbersome and seems lots of weight in it...it would be my last option....but I don't have any other skills or resources to build a blade any other way than shown in plans.... The two sources I have in china are opting to build a blade without root features for my hub...which makes me afraid might spend cash only blades to get here and are impossible to edit the root
Thanks Peter, no vibrations of any concern, it was quite breezy up there (and I'm not talking about the downwash). Next stage is to lengthen the tethers and start testing the cyclic response, from here on things get interesting. I transported the helicopter up to a friends farm, he kindly let me use his 10 acre field, felt much safer with nothing around.
How did you get past the CAA interfering, they keep homebuilt helicopter as their control entirely????? How would you explain flying with an underslung trailer?
Thanks. 👍 in this video the spacing was longer than it is now, I have reduced it to 10% rotor diameter which is where I think it should be after reading a study on the subject. This has also been agreed with by a few knowledgeable people I've had contact with. I'm expecting the rotor thrust to increase on the next test.
Because the lower rotor is working in the downwash of the top rotor lift is decreased and so is the torque. It's balanced now and a one degree difference is what was needed.
Wow, Notice the abscence of Collective? these blades are fixed pitch, there are no normal helicopter linkages, its pull on the throttle which means its not a real helicopter than can autorotate. Contra rotating blades are far more stable but still need to change pitch if there is an engine failure. This machine cannot be flow anywhere other than ground hover without the risk of certain death from an engine failure.
I've not used a 3d printer before but I've seen people use them to make some complicated parts. Will have to get one myself one day. My only reservation is the strength of the parts it produces, in plastic anyway.
Thank you, it's quite a feeling to get off the ground for the first time, I'm sure you can remember on your first flying machine. Thanks for the inspiration.
Hi, thanks. No blue prints are available at the moment. There's one more design hurdle to overcome which is flight controllability, if this passes then I would consider selling plans. Depends on how much interest there is I suppose. I would have to consider whether it was morally right to sell plans as this helicopter is designed as a fun field vehicle which should only be used a few feet above the ground, no higher as it can't auto rotate. If I added collective pitch then it would be safer as you could then auto rotate in the event of an engine failure.
Thank you, yes fixed pitch just the rotor rpm to control altitude. Only a very short tether but it did seem to respond well to throttle inputs, certainly encouraging.
That was the first thought in my mind as well. Also I don’t see any swashplate and pitch change links. How do you intend to control direction. I can see that using engine RPM will affect overall lift in lieu of having a collective control, but you still need to be able to control forward speed and direction. I’m intrigued to know what your answer is this.
@@alanwhitfield1907 Instead of swash plates and cyclic feathering of the blades the whole mast assembly tilts on a gimbal. Its considered a mixture of tilt mast and weight shift. Have a look at the Nolan pendulum helicopter and bensen B9. The Nolan was a super machine and very well demonstrated but not much is known about how the control compares to standard swash plate control. ruclips.net/video/B21Xk6tNcBw/видео.html
do you know the power band of that motor and it's safe operating rpm? it looks like you didnt get lift till way up in rpm. Perhaps you need more Blade to get the power to the wings a little earlier.
In this video the engine is running at around 5500rpm and it's standard maximum is 6500rpm. Because I've made the exhaust expansion chambers I'm not sure what the power is now or the band. Since this video I've done more testing and added much more weight, but it's now fully capable of free flight. I just need to learn how to control it.
Have you changed the jetting on the carb's? Expansion chambers very often demand quite a lot more fuel and I'd hate to see you seize it or hole a piston.
Thanks for the comment and it's something I'm worried about, I haven't altered the Jetting and like you say I need to find out what the air fuel mixture is like. Need to do some research and perhaps install some exhaust gas temperature sensors.
Wow best possible secure way to approach a rotor and other lift tests . Hover test with line attached . Your safety concerns are very up to date even tiny spinning test we all must put crash helmet and seat belts on , remember the demice of 28 old febrication mechanic called Munna in Maharashtra ,India few months ago ? Piece of tail rotor after stripping off from assembly hit the top rotor Making big twist to body in oppiste direction and then hit his head ,he wasn't neither wearing helmet nor seat belts .have you watched that unfortunate video ? The rotors your helicopter were rotating with out vibrations and we can see even lifting off was okay to ... success is there . Great job brother 👍 congratulations .
Thank you, yes after watching the tragic munna helicopter test I immediately added the safety belts which would have likely saved Munna. He was still very unlucky but it showed us what can happen.
@@rajeevshagun7409 I'm not sure what rpm he was running the tail rotor at but it should be around 500-600 ft/sec tip speed. This would put the tail rotor at around 2700 rpm with a 4ft diameter rotor. What others have done is speed up the tail rotor to double the rpm to test it, but you can work out the load on the rotor hubs and calculate the strength of material needed. You want a nice big factor of safety for rotor hubs.
@@Ben-Dixey ideally he should had 6 times more RPM then main rotors RPM , earlier in garage it seemed okay but this fatal test , it seemed running 10-12 times more then RPM of main rotors .
@@Ben-Dixey oh nevermind that's a boat engine. I figured since it was 2 stroke it'd be a bike engine. I suppose the switching gears would making flying really difficult wouldn't it
Thanks for the comment. Would like a 4 stroke or Diesel engine. The obvious would be a rotax or Hirth aircraft engine, air cooled would be ideal. Something to look at in the future for sure.
Maybe make the chambers out of 0.6 mil steel. Aluminum can not resist the temperatures and vibration and will always crack unless you make it so thick that there will be no weight advantage. You don't want to experience a crack when actually flying, the power drop will be significant . Look into hydroforming for your exhausts, it simplifies the design and the amount off welds needed, so lesser potential points of failure. Make your calculations with the chambers to prevent the engine to become to peaky, volume and length are your friends here to keep a torque and not only max HP. The tailpipe and mufflers don't need to be at the end of the pipe, think of them as overpressure valves and mount them were its convenient. Leaving your brass balls at home might help you lifting off😁.
Thanks for this. I think you're right about using 0.6mm steel over aluminium the vibration issue I'm sure will cause cracking at some point in Ali. The exhaust gas temperature I think I calculated to be around 350degC well below the melting point. Hydroforming would definitely be worth trying next time as long as it comes out half decent I would be happy. The exhaust tuning side of things I used the calculations from the AU mechanic on RUclips, brilliant set of videos going through it all, i used the figures for broad power rather than peak power and the pipe dimension were altered accordingly, the tuned length is quite long. You mention the muffler doesn't have to be on the end of the pipe, could you expand on that ? Cheers
@@Ben-Dixey You can have the tailpipe (or stinger ) welded somewhere in the midsection of the chamber without any negative effects on the engines characteristics. In the 80's I used to race with a Yamaha TZ750 and my set of pipes for rainy weather or circuits with many short corners were like this. Because I could make the pipes longer it helped me with gaining bottom power, lowering the powerband by approx. 300 revs. , making the bike less twitchy to drive, but losing top speed. I am not sure if expansion chambers are the way to go, because they will narrow your powerband, forcing you to check revs constantly . When a two stroke gets "off the pipe", the power loss is substantial and before the engine is revved up enough to profit from the pipe, some time will have passed. You don't have a gearbox and clutch to compensate for these things, just altitude. Not something you want to happen on the wrong moment, real live is not a cartoon. Look at the rotax aircraft engines, they don't have expansion chambers and deliver power over a wide powerband. Might be worthwhile to have a chat with someone in the know or try to find some information about what pipes they use (aftermarket catalogues anyone?). Engine manufacturers have bigger wallets then you ( I suppose) and have already figured these things out in the past.
Understood, I remember seeing somewhere about the tail pipe being inserted into the baffle cone and it not affecting power. I think I didn't do this as I needed the tail pipe to do a 180 for muffler fitting purposes. The 2 stroke aircraft engines as you say don't have expansion chambers and I'm sure they designed them for reliability over peak power. I have the dimensions of a 50hp Hirth aircraft engine exhaust and was going to copy it. Then I started researching expansion chambers and decided I wanted the best chance of lifting off rather than reliability. After the prototype machine has been proven to fly under control I might well revisit the exhaust and try the copied Hirth design. The helicopter in its current format is only going to be flown at a few feet and no higher for other safety reasons than the engine reliability issues. I've done 3 more videos since this one and performance wise the exhausts are working for me. I tried a generic eBay exhaust and the helicopter wouldn't lift off the ground so something is working. Any ideas what Hp gain it's likely to have from adding expansion chambers on a 60hp outboard power head ?
@@Ben-Dixey Given that a normal outboard exhaust is just some collection area that vents under the waterline, I can only assume that it doesn't get worse. Beware that expansion chambers can have some very expensive side effects on cylinder heads and pistons(don't ask me how I know😭), so keep an eye on your jetting, you don't want the engine run to lean. Better keep mixture on the richer side to help cooling your pistons. How many degrees is the exhaust port timing? Small tip: To prevent cracking of the exhausts it is best when mounted with springs at the cylinder side and rubber silent blocks further down the line.
@@dutchsailor6620Someone else warned me about running lean with the expansion chambers. I've been checking the spark plugs against a chart comparing lean to rich and they look ok to me but I haven't gone any more scientific than that. The exhaust port timing is 168.5 degrees. I've got the expansion chambers mounted on springs but there is approximately 6" of rigid tube from the manifold before the springs. I had an issue with a rubber mounting bracket broken from the vibration, I added another mounting point further back and it hasn't broken again. How have you checked the mixture before ? gas analyzer?
Even minor damage to moving mechanical parts caused by stress and strain on the parts. It leads you to death. Rigorous engineering testing is required. Hope you don't take off.
How much do you know already ? A helicopter is one of the hardest things to make in my opinion. I've had a lot of engineering experience before attempting a project like this.
@@Ben-Dixey i want learn a part of main rotor how to make rotor can move forward,backword and beside simultaneously. second part is tail rotor whici how to fit go beside and fit with main rotor? just that my question
@@Muss_._ my helicopter is different to most other helicopters in how it's controlled. my helicopter does not have a tail rotor as it does not need one. The main rotor tilts in the direction you want to go. This is different from a single rotor helicopter and that is controlled with a swash plate which alters the blades pitch several times each rotation for control. A single rotor helicopter needs a tail rotor a coaxial helicopter does not.
The video demonstrates the helicopter can actually fly, it's tethered to the Trialer for safety but lifted off a couple inches. This was a massive achievement after five years of designing, building and testing. The videos after show it hovering up to three feet now.
@@Ben-Dixey Your doubt is WRONG! I did watch the whole thing!! Stop thinking you know what I did or didn’t do. That’s the problem with social media, people jump in and think they’re in tune with a subject matter and have absolutely NO FUCKING idea what a person meant with a comment! Mind your own goddamn business!!
Wow. You have some issues! Why is your negative comment on my video not my business ? You think you have a right to say whatever you like without question ? I would never write a comment like that on someone's video. Usually people lash out unprovoked because of problems in their own life.
If you watched the whole clip, 7 minutes and 3 seconds. But let’s not forget the time, and mental capacity you had to put into being able to string the 3 words and an emoji together to respond, that must have taken you at least another 7 minutes. So total time lost for your viewing and ‘contribution’ circa 14 minutes and 3 seconds. Now, how long did it take you to read the replies? Another 7 minutes? Maybe more? Let’s round it up to 10 minutes… so, we have 7 minutes 3 seconds, plus 7 minutes, plus another 10 minutes, do you need a calculator…? I make 24 minutes and 3 seconds of your time ‘wasted’. So really, the time you spent interjecting your thoughts at the start in response to the video, if you had just simply clicked off the video, or even clicked dislike and gone on your merry way, that would have saved you at least 17 minutes!! I think there’s a lesson in there for all of us…! Have a great day!
@@quadtraxxx Amazing! You learned some math and a little bit of English. Actually I think your parents got robbed sending you to school! Now that was wasted time!!
Beautiful. This has been a dream of mine since childhood. Well done. Can't wait to see more. Stay safe.
Thanks for the kind words, it's nice to get some answers to some questions. More to come. 👍
Upload your flying video,
Good on you Ben. In engineering you never learn less. I bet you're well pleased. Keep up the great work.
Thank you, 👍 yes I'm very pleased how it's all gone. Quite a summer of testing and learning about helicopters.
Beautiful feeling and results... especially for an own design, that's on another level...those design plans needs to hit the market soonest😄
Thanks Jeff, you will too experience the thrill, it's quite something. You have come along way in a short time and I can see you will get there. 👍
@@Ben-Dixey quick question...per plans blades are 6inch cord(154mm) what would be the consequences if I fitted blades 7inch(178mm) cord...
Finding a good blade deal in China...
@@JeffChoppah I don't think it would make a lot of difference in performance, maybe more lift at a slightly lower rpm. You just need to check the blade weight difference. The plans designed blades look pretty heavy to me but you can calculate the weight from the drawings. The rotor hubs should be designed to take way in excess of the centrifugal forces but I would be checking it all for piece of mind. I can help here if you need it. The blade weight and speed will effect the coning angle which changes the teeter undersling but I doubt it be far enough out to cause any issues.
@@Ben-Dixey these conning angle calculations and effects on engine was what was worrying me...the length I can maintain as per plans but cord they have 7inch... building it as shown in plans is cumbersome and seems lots of weight in it...it would be my last option....but I don't have any other skills or resources to build a blade any other way than shown in plans....
The two sources I have in china are opting to build a blade without root features for my hub...which makes me afraid might spend cash only blades to get here and are impossible to edit the root
@@JeffChoppah what type blades are they ? Extruded aluminium or composite ? Do you know the weight /ft ?
Ah well done Ben it sounds quite healthy the rotors run true looks really compact, no unruly vibrations,it that field part of your acreage ?
Thanks Peter, no vibrations of any concern, it was quite breezy up there (and I'm not talking about the downwash). Next stage is to lengthen the tethers and start testing the cyclic response, from here on things get interesting. I transported the helicopter up to a friends farm, he kindly let me use his 10 acre field, felt much safer with nothing around.
Can you shorten the shaft between the rotor blades? Cool project
Yes I did, dropped it to 10% rotor diameter. 👍
Brilliant. I'm slightly triggered though that you increase collective by pushing instead of pulling.
I'm really looking forward for free flight vids
Yes I'll change this to conventional 👍
Cool, does the difference in pitch ensure they both have the same AOA so torque is equalised across both discs?
Yes I believe that is correct, the downward flow of air onto the bottom rotor reduces its angle of attack.
Very good, looking forward to the next step, will you try longer tethers?
Yes, longer tethers next and start playing with cyclic control. Still a lot to do but from now on things get interesting.
A piece of brain the inventor has is awesome love from India sir,just add a blade in the propeller 3:3 you can get more power in same rpm...
Hi and thanks. Things have progressed since this video.
ruclips.net/video/XLKrlMDiht4/видео.html
How did you get past the CAA interfering, they keep homebuilt helicopter as their control entirely????? How would you explain flying with an underslung trailer?
During the hovering the machine is tethered at all times. Ground anchors and cables. I think tethered is ok but I might be wrong.
@@Ben-Dixey I was joking about the trailer at a ton weight.
Sorry yes. 😆 my friend suggested there must be easier ways to move the trailer around.
Excellent build ! How did you arrive to the spacing between the rotors ?
Thanks. 👍 in this video the spacing was longer than it is now, I have reduced it to 10% rotor diameter which is where I think it should be after reading a study on the subject. This has also been agreed with by a few knowledgeable people I've had contact with. I'm expecting the rotor thrust to increase on the next test.
Nicely done. Why different pitches in the two rotors? That will surely result in unwanted yaw.
Because the lower rotor is working in the downwash of the top rotor lift is decreased and so is the torque. It's balanced now and a one degree difference is what was needed.
Wow, Notice the abscence of Collective? these blades are fixed pitch, there are no normal helicopter linkages, its pull on the throttle which means its not a real helicopter than can autorotate. Contra rotating blades are far more stable but still need to change pitch if there is an engine failure.
This machine cannot be flow anywhere other than ground hover without the risk of certain death from an engine failure.
I thought contra rototating blades would be more stable. They definitely aren't, no more stable than an R22.
Yes only a couple feet.
This is great. I’m planning on making my own and I already have some ideas!
👍 full scale or model ?
@@Ben-Dixey full scale
I’m getting a 3d printer soon which can be used for precision parts
I've not used a 3d printer before but I've seen people use them to make some complicated parts. Will have to get one myself one day. My only reservation is the strength of the parts it produces, in plastic anyway.
@@Ben-Dixey I’m planning on it being electronically powered but I don’t know if that wil work
Congratulation's on your beautiful machine and may you have many safe successful flights ahead.
Thank you for sharing. We hope to see you in full flight soon. Good luck!!
a pusher prop on the back would make that thing awesome.
Sir plz change the sparkplug with iridium tip sparkplug and use engine adhesive in engine oil to reduce vibration,wear and tear too
Congratulations, -what a mile stone!
Well done!
Thank you, it's quite a feeling to get off the ground for the first time, I'm sure you can remember on your first flying machine. Thanks for the inspiration.
Bloody great, can't wait to see you flying👍🇬🇧
I love ur design, what are u asking for ur blueprints? I'd like to build one sir
Hi, thanks. No blue prints are available at the moment. There's one more design hurdle to overcome which is flight controllability, if this passes then I would consider selling plans. Depends on how much interest there is I suppose. I would have to consider whether it was morally right to sell plans as this helicopter is designed as a fun field vehicle which should only be used a few feet above the ground, no higher as it can't auto rotate. If I added collective pitch then it would be safer as you could then auto rotate in the event of an engine failure.
congrats , been following for 4 months or so , incredible work !
Thanks Rob 👍
What a great video, is it fixed pitch? I did not see you operate any collective levers.
Thank you, yes fixed pitch just the rotor rpm to control altitude. Only a very short tether but it did seem to respond well to throttle inputs, certainly encouraging.
That was the first thought in my mind as well. Also I don’t see any swashplate and pitch change links. How do you intend to control direction. I can see that using engine RPM will affect overall lift in lieu of having a collective control, but you still need to be able to control forward speed and direction. I’m intrigued to know what your answer is this.
@@alanwhitfield1907 Instead of swash plates and cyclic feathering of the blades the whole mast assembly tilts on a gimbal. Its considered a mixture of tilt mast and weight shift. Have a look at the Nolan pendulum helicopter and bensen B9. The Nolan was a super machine and very well demonstrated but not much is known about how the control compares to standard swash plate control.
ruclips.net/video/B21Xk6tNcBw/видео.html
do you know the power band of that motor and it's safe operating rpm? it looks like you didnt get lift till way up in rpm. Perhaps you need more Blade to get the power to the wings a little earlier.
In this video the engine is running at around 5500rpm and it's standard maximum is 6500rpm. Because I've made the exhaust expansion chambers I'm not sure what the power is now or the band. Since this video I've done more testing and added much more weight, but it's now fully capable of free flight. I just need to learn how to control it.
Have you changed the jetting on the carb's? Expansion chambers very often demand quite a lot more fuel and I'd hate to see you seize it or hole a piston.
Thanks for the comment and it's something I'm worried about, I haven't altered the Jetting and like you say I need to find out what the air fuel mixture is like. Need to do some research and perhaps install some exhaust gas temperature sensors.
Wow best possible secure way to approach a rotor and other lift tests . Hover test with line attached .
Your safety concerns are very up to date even tiny spinning test we all must put crash helmet and seat belts on , remember the demice of 28 old febrication mechanic called Munna in Maharashtra ,India few months ago ?
Piece of tail rotor after stripping off from assembly hit the top rotor Making big twist to body in oppiste direction and then hit his head ,he wasn't neither wearing helmet nor seat belts .have you watched that unfortunate video ?
The rotors your helicopter were rotating with out vibrations and we can see even lifting off was okay to ... success is there .
Great job brother 👍 congratulations .
Thank you, yes after watching the tragic munna helicopter test I immediately added the safety belts which would have likely saved Munna. He was still very unlucky but it showed us what can happen.
@@Ben-Dixey did you feel any thing strange regarding RPM of tail rotors of Munna helicopter ?
@@rajeevshagun7409 I'm not sure what rpm he was running the tail rotor at but it should be around 500-600 ft/sec tip speed. This would put the tail rotor at around 2700 rpm with a 4ft diameter rotor. What others have done is speed up the tail rotor to double the rpm to test it, but you can work out the load on the rotor hubs and calculate the strength of material needed. You want a nice big factor of safety for rotor hubs.
@@Ben-Dixey ideally he should had 6 times more RPM then main rotors RPM , earlier in garage it seemed okay but this fatal test , it seemed running 10-12 times more then RPM of main rotors .
what kind of engine did you base it on?
It's a 60hp Johnson outboard engine. 2cylinder 2 stroke, the tuned exhausts might have increased the power above 60 though.
@@Ben-Dixey dude. So it's a manual trans??? How did you connect the propellers to the drive train
@@Ben-Dixey oh nevermind that's a boat engine. I figured since it was 2 stroke it'd be a bike engine. I suppose the switching gears would making flying really difficult wouldn't it
That's it, one gear and one speed, I've seen some homebuilt helicopters that have used a multi gear transmission but it's pointless additional weight.
Very nice work! I would just move away from the outboard powerplant and get something more reliable. Other than that great work!
Thanks for the comment. Would like a 4 stroke or Diesel engine. The obvious would be a rotax or Hirth aircraft engine, air cooled would be ideal. Something to look at in the future for sure.
Hello
How many horsepower is the engine?
Hi, 60hp but I have modified the exhausts so it could have more. I can't say exactly until the engine is put on a dyno.
Maybe make the chambers out of 0.6 mil steel. Aluminum can not resist the temperatures and vibration and will always crack unless you make it so thick that there will be no weight advantage. You don't want to experience a crack when actually flying, the power drop will be significant . Look into hydroforming for your exhausts, it simplifies the design and the amount off welds needed, so lesser potential points of failure. Make your calculations with the chambers to prevent the engine to become to peaky, volume and length are your friends here to keep a torque and not only max HP. The tailpipe and mufflers don't need to be at the end of the pipe, think of them as overpressure valves and mount them were its convenient. Leaving your brass balls at home might help you lifting off😁.
Thanks for this. I think you're right about using 0.6mm steel over aluminium the vibration issue I'm sure will cause cracking at some point in Ali. The exhaust gas temperature I think I calculated to be around 350degC well below the melting point.
Hydroforming would definitely be worth trying next time as long as it comes out half decent I would be happy.
The exhaust tuning side of things I used the calculations from the AU mechanic on RUclips, brilliant set of videos going through it all, i used the figures for broad power rather than peak power and the pipe dimension were altered accordingly, the tuned length is quite long.
You mention the muffler doesn't have to be on the end of the pipe, could you expand on that ? Cheers
@@Ben-Dixey You can have the tailpipe (or stinger ) welded somewhere in the midsection of the chamber without any negative effects on the engines characteristics. In the 80's I used to race with a Yamaha TZ750 and my set of pipes for rainy weather or circuits with many short corners were like this. Because I could make the pipes longer it helped me with gaining bottom power, lowering the powerband by approx. 300 revs. , making the bike less twitchy to drive, but losing top speed. I am not sure if expansion chambers are the way to go, because they will narrow your powerband, forcing you to check revs constantly . When a two stroke gets "off the pipe", the power loss is substantial and before the engine is revved up enough to profit from the pipe, some time will have passed. You don't have a gearbox and clutch to compensate for these things, just altitude. Not something you want to happen on the wrong moment, real live is not a cartoon. Look at the rotax aircraft engines, they don't have expansion chambers and deliver power over a wide powerband. Might be worthwhile to have a chat with someone in the know or try to find some information about what pipes they use (aftermarket catalogues anyone?). Engine manufacturers have bigger wallets then you ( I suppose) and have already figured these things out in the past.
Understood, I remember seeing somewhere about the tail pipe being inserted into the baffle cone and it not affecting power. I think I didn't do this as I needed the tail pipe to do a 180 for muffler fitting purposes.
The 2 stroke aircraft engines as you say don't have expansion chambers and I'm sure they designed them for reliability over peak power. I have the dimensions of a 50hp Hirth aircraft engine exhaust and was going to copy it. Then I started researching expansion chambers and decided I wanted the best chance of lifting off rather than reliability. After the prototype machine has been proven to fly under control I might well revisit the exhaust and try the copied Hirth design. The helicopter in its current format is only going to be flown at a few feet and no higher for other safety reasons than the engine reliability issues. I've done 3 more videos since this one and performance wise the exhausts are working for me. I tried a generic eBay exhaust and the helicopter wouldn't lift off the ground so something is working. Any ideas what Hp gain it's likely to have from adding expansion chambers on a 60hp outboard power head ?
@@Ben-Dixey Given that a normal outboard exhaust is just some collection area that vents under the waterline, I can only assume that it doesn't get worse. Beware that expansion chambers can have some very expensive side effects on cylinder heads and pistons(don't ask me how I know😭), so keep an eye on your jetting, you don't want the engine run to lean. Better keep mixture on the richer side to help cooling your pistons. How many degrees is the exhaust port timing? Small tip: To prevent cracking of the exhausts it is best when mounted with springs at the cylinder side and rubber silent blocks further down the line.
@@dutchsailor6620Someone else warned me about running lean with the expansion chambers. I've been checking the spark plugs against a chart comparing lean to rich and they look ok to me but I haven't gone any more scientific than that.
The exhaust port timing is 168.5 degrees.
I've got the expansion chambers mounted on springs but there is approximately 6" of rigid tube from the manifold before the springs. I had an issue with a rubber mounting bracket broken from the vibration, I added another mounting point further back and it hasn't broken again. How have you checked the mixture before ? gas analyzer?
Incredible work!
Bravo!
Kobe!!!!
Hi, what is diameter of your two rotor?
Hi 4.3m
Okay, thankyou,
По началу меня смутило, что ты сделал выхлопную из алюминиевого сплава :)
Yes, I chose aluminium for weight reasons and don't know if it was the right decision. The vibration cracking welds could be a problem.
How do the coaxial rotors work?
That's a big question but the point is to equalise the torque on the airframe so you don't need a tail rotor.
@@Ben-Dixey true,
Blade needs one more feet in length
Many more videos since this one demonstrating flight but yes more lift would result from longer blades.
Even minor damage to moving mechanical parts caused by stress and strain on the parts. It leads you to death. Rigorous engineering testing is required. Hope you don't take off.
There are loads more videos after this one.
not that it isnt awesome already it is amazing
Thank you 👍
Yaaaaaaa. 😀👍✋🙏
👍👍👍👍
can u teach me how to make this helicopter?
How much do you know already ? A helicopter is one of the hardest things to make in my opinion. I've had a lot of engineering experience before attempting a project like this.
@@Ben-Dixey i want learn a part of main rotor how to make rotor can move forward,backword and beside simultaneously.
second part is tail rotor whici how to fit go beside and fit with main rotor? just that my question
@@Muss_._ my helicopter is different to most other helicopters in how it's controlled. my helicopter does not have a tail rotor as it does not need one. The main rotor tilts in the direction you want to go. This is different from a single rotor helicopter and that is controlled with a swash plate which alters the blades pitch several times each rotation for control. A single rotor helicopter needs a tail rotor a coaxial helicopter does not.
@@Ben-Dixey ouh... i was find many platform for learn anyknowledge but still not yet
👏👏👍👍🚁🚁🚁
I don't understand what was the purpose of the video that nothing useful was seen, a man sitting without doing anything
The video demonstrates the helicopter can actually fly, it's tethered to the Trialer for safety but lifted off a couple inches. This was a massive achievement after five years of designing, building and testing. The videos after show it hovering up to three feet now.
u need a min of 85 hp
May I ask where you got that figure from ?
🤣🤣😪😭😭👺
Why not just buy plans? As this item you have created is a complete danger to you and anyone around you
You can't buy plans for a coaxial. Where is the challenge in building from plans ?
Wasted 7 minutes.😡
I'm not sure what you were expecting ? I also very much doubt you watched the whole video otherwise you would have understood it.
@@Ben-Dixey Your doubt is WRONG! I did watch the whole thing!! Stop thinking you know what I did or didn’t do. That’s the problem with social media, people jump in and think they’re in tune with a subject matter and have absolutely NO FUCKING idea what a person meant with a comment! Mind your own goddamn business!!
Wow. You have some issues! Why is your negative comment on my video not my business ? You think you have a right to say whatever you like without question ? I would never write a comment like that on someone's video. Usually people lash out unprovoked because of problems in their own life.
If you watched the whole clip, 7 minutes and 3 seconds. But let’s not forget the time, and mental capacity you had to put into being able to string the 3 words and an emoji together to respond, that must have taken you at least another 7 minutes. So total time lost for your viewing and ‘contribution’ circa 14 minutes and 3 seconds. Now, how long did it take you to read the replies? Another 7 minutes? Maybe more? Let’s round it up to 10 minutes… so, we have 7 minutes 3 seconds, plus 7 minutes, plus another 10 minutes, do you need a calculator…? I make 24 minutes and 3 seconds of your time ‘wasted’. So really, the time you spent interjecting your thoughts at the start in response to the video, if you had just simply clicked off the video, or even clicked dislike and gone on your merry way, that would have saved you at least 17 minutes!! I think there’s a lesson in there for all of us…! Have a great day!
@@quadtraxxx Amazing! You learned some math and a little bit of English. Actually I think your parents got robbed sending you to school! Now that was wasted time!!
Awesome!! Very well done!! And people said it wouldn’t work… 😉👍
Thank you, it was a great day today. Definitely on a high.