Ynot’s Human Powered Helicopter Attempt - Page 6

ynot · 26th January 2013, 05:41 PM

Video of the Atlas Team's 30 second, five feet flight - http://www.youtube.com/watch?v=hm8Lv...ature=youtu.be

Some more info here - http://www.aerovelo.com/2013/01/26/p...ng-very-close/

Would like to see video of the failed prize attempt flight.

Is anyone else still interested or am I just talking to myself here?

Mister Earl · 26th January 2013, 06:10 PM

*Definitely* interested. I keep thinking of ways to do it myself. Hehe. But not being an engineer, I don't have a realistic dog in this fight. My participation is theoretical. My interest in this challenge is not.

Marcus · 26th January 2013, 07:35 PM

Originally Posted by ynot

Video of the Atlas Team's 30 second, five feet flight - http://www.youtube.com/watch?v=hm8Lv...ature=youtu.be

Some more info here - http://www.aerovelo.com/2013/01/26/p...ng-very-close/

Would like to see video of the failed prize attempt flight.

Is anyone else still interested or am I just talking to myself here?

Two things strike me about this flight. First is that their design is not able to absorb the full power of their pilot, for the reasons they stated, and the second is that they are not using an optimal power plant. I wonder what someone could do with a world class climber or sprinter at the pedals coupled with a machine that could take the power.

Myriad · 26th January 2013, 08:27 PM

Originally Posted by ynot

Video of the Atlas Team's 30 second, five feet flight - http://www.youtube.com/watch?v=hm8Lv...ature=youtu.be

Some more info here - http://www.aerovelo.com/2013/01/26/p...ng-very-close/

Wow, that thing is huge. It took me a while to visually parse the photograph; things that I thought at first were parts of the building are actually parts of the vehicle, and vice versa. Interesting that they went with a giant quadrotor. That pyramid of long support trusses must have a high cost in weight and power distribution issues, so the design must have some really big upsides to be worth it.

Quote:

Is anyone else still interested or am I just talking to myself here?

Interested.

Respectfully,
Myriad

ynot · 26th January 2013, 08:33 PM

Originally Posted by Mister Earl

*Definitely* interested. I keep thinking of ways to do it myself. Hehe. But not being an engineer, I don't have a realistic dog in this fight. My participation is theoretical. My interest in this challenge is not.

Great - I'll keep rambling on then.

ynot · 26th January 2013, 08:39 PM

Originally Posted by Marcus

Two things strike me about this flight. First is that their design is not able to absorb the full power of their pilot, for the reasons they stated, and the second is that they are not using an optimal power plant. I wonder what someone could do with a world class climber or sprinter at the pedals coupled with a machine that could take the power.

Even before their prize attempt I thought it was maybe more to do with publicity for fundraising purposes rather than a serious attempt at winning. If nothing else the Atlas Team are by far the best at fundraising. I don't see 30 secs and 5 ft as being as "close" as they claim. Gamera have done better and I don't think even they can claim to be "close".

ynot · 26th January 2013, 08:43 PM

Originally Posted by Myriad

Wow, that thing is huge. It took me a while to visually parse the photograph; things that I thought at first were parts of the building are actually parts of the vehicle, and vice versa. Interesting that they went with a giant quadrotor. That pyramid of long support trusses must have a high cost in weight and power distribution issues, so the design must have some really big upsides to be worth it.

Very similar design to the more successful Gamera - http://www.agrc.umd.edu/gamera/index.html
Both are copies if the earlier (1994) Yuri - http://www.youtube.com/watch?v=caHCb...ture=endscreen

Originally Posted by Myriad

Interested.

Respectfully,
Myriad

Great.

ynot · 26th January 2013, 09:17 PM

Originally Posted by Myriad

That pyramid of long support trusses must have a high cost in weight and power distribution issues, so the design must have some really big upsides to be worth it.

The design allows all wings to be close to the ground to begin with to gain an advantage from ground effect. Trouble is that advantage all but disappears before you get to the required 3 metres height.

Marcus · 28th January 2013, 05:32 AM

ynot, I've been looking through the videos you've posted on this thread and I was wondering. Has anyone tried a really well done single prop made with advanced composites, a drive train optimized to reduce friction, and a sprinter who can put out 1500 watts for short periods of time? Or is it really just impossible without using these giant 4 prop designs?

CynicalSkeptic · 28th January 2013, 09:55 AM

Originally Posted by ynot

Great - I'll keep rambling on then.

Also interested. Have little to contribute, but I've been fascinated with the videos I've seen as well as what I've read here.

ynot · 28th January 2013, 10:50 AM

Originally Posted by Marcus

ynot, I've been looking through the videos you've posted on this thread and I was wondering. Has anyone tried a really well done single prop made with advanced composites, a drive train optimized to reduce friction, and a sprinter who can put out 1500 watts for short periods of time? Or is it really just impossible without using these giant 4 prop designs?

There have been a few but counter-rotation is always a problem with a single rotor set. To have a tail rotor that doesn’t provide lift is a waste of energy you don’t have enough of to begin with. So most use multiple counter-rotating or off-set rotor sets.

The Upturn uses one set of rotors that are self-rotated with props at the ends of the rotors so no counter-rotation is created.- http://www.ntsworks.com/New_Helicopter.html

The Da Vinci had some sort of prop (not at a tail) but it didn’t stop it from counter rotating. I think this was the first HPH to ever get off the ground (I could be wrong) - http://www.youtube.com/watch?v=vYmF7-JWCVA

I Haven’t seen any HPH attempt that uses two pilots so if nothing else my attempt would at least be original (no prize for that tho). My design uses two coaxial, counter-rotating wing-sets and the power of the pilots is applied directly to the wings so there is essentially no drive train.

ynot · 28th January 2013, 10:56 AM

Originally Posted by CynicalSkeptic

Also interested. Have little to contribute, but I've been fascinated with the videos I've seen as well as what I've read here.

Thanks. I guess that this thread has had over 5,000 views should be an indication that some people are interested even if they aren’t posting.

CriticalThanking · 31st January 2013, 11:30 AM

[delurk]
Interested. I hear Lance Armstrong may be available. I didn't see anything in the rule set about doping.
[/delurk]

ynot · 31st January 2013, 12:53 PM

Originally Posted by CriticalThanking

[delurk]
Interested. I hear Lance Armstrong may be available. I didn't see anything in the rule set about doping.
[/delurk]

Sorry but the rules state . . .

"4.2.3 No drugs or stimulants shall be used by any member of the crew. An assurance must be given to the official observers at the time of the attempt that this requirement has been met."

Lance could try lying of course.

Marcus · 1st February 2013, 05:11 AM

Maybe you could get Mark Cavendish to do it. A world record with a nice vacation in New Zealand, why not.

ynot · 1st February 2013, 11:53 AM

Originally Posted by Marcus

Maybe you could get Mark Cavendish to do it. A world record with a nice vacation in New Zealand, why not.

My design uses two pilots so does Mark have a twin brother? It also uses more of a rowing action not pedalling so perhaps top rowers would be a better choice. NZ just happens to have quite a few world class rowers. Of course my design will be so effective and efficient any two reasonably light, strong and fit people will do the job (what, me deluded?)

.

ynot · 1st February 2013, 12:06 PM

I’m building my frame and transmission but every time I think I have a final design and get half way through building it I think of some improvement and have to start over. Hope this time I will get it completed but I don‘t mind delays for improvements. Although I‘m using low-tech aluminium and some bike bit’s I’m confident that the frame/transmission is going to be lighter per pilot than any other design I‘ve seen. Maybe even lighter regardless. Did I mention it will also be more effective and efficient? Oh yes I did

tsig · 1st February 2013, 12:22 PM

Originally Posted by ynot

Thanks. I guess that this thread has had over 5,000 views should be an indication that some people are interested even if they aren’t posting.

Interested just don't have much to contribute so I lurk.

tsig · 1st February 2013, 12:23 PM

Originally Posted by ynot

I’m building my frame and transmission but every time I think I have a final design and get half way through building it I think of some improvement and have to start over. Hope this time I will get it completed but I don‘t mind delays for improvements. Although I‘m using low-tech aluminium and some bike bit’s I’m confident that the frame/transmission is going to be lighter per pilot than any other design I‘ve seen. Maybe even lighter regardless. Did I mention it will also be more effective and efficient? Oh yes I did

Pics?

Please.

ynot · 1st February 2013, 12:57 PM

Design change update . . .

I’ve changed the action of the pilots from what I’ve previously explained. To begin with I had the two pilots applying their energy (push/pulls) directly against each other (pilot to pilot) to prevent counter-rotation. This would’ve required the energy of both pilots to be constantly equally and oppositely balanced. I didn’t think this would have been much of a problem to achieve but others did.

I’m now using more of a rowing action and each pilot will be pulling with their arms against a push with their legs so the opposing forces cancel each other out in a counter-rotation sense. The actions of the pilots are now independent of each other and as one is “resetting” the other is “powering” so there always a constant application of energy to the wings. As the reset stroke is much faster then the power stroke most of the time both are on the power stroke. Previously each pilot moved one wing-set each but now they both move both. The pilots aren’t on sliding seats as with rowing as this would require them to be wasting energy moving their body weight and would also create more overall imbalance. They are now both sitting upright which is possibly more ergonomic than the previous up-down configuration.

So now the overall design is - Two coaxial counter-rotating wing-sets with two pilots positioned below them. The pilots use independent rowing actions to provide the power.

ynot · 1st February 2013, 01:30 PM

Originally Posted by tsig

Pics?

Please.

Don’t really have anything built enough at this stage to provide any pics of. I’m also not completely comfortable publishing exact details of everything until it‘s all closer to being completed. Not sure if this is inventors paranoia or there is any real danger that others might borrow my ideas and use them before I do. I appreciate how open some other teams are with their information but they have been working on their attempts for years and are essentially only copying and improving the earlier attempts of others. I’m trying to be as descriptive as I can with words so that anyone with reasonable mechanical ability should be able to get the pic in their mind. Might post some schematic drawings to make general concepts clearer if I get time to draw them.

Marcus · 2nd February 2013, 05:35 AM

Originally Posted by ynot

My design uses two pilots so does Mark have a twin brother? It also uses more of a rowing action not pedalling so perhaps top rowers would be a better choice. NZ just happens to have quite a few world class rowers. Of course my design will be so effective and efficient any two reasonably light, strong and fit people will do the job (what, me deluded?)

.

My bad, I should have paid closer attention.

I'm not so sure using rowers instead of cyclists will improve the strength to weight ratio, many of the top cyclists are already running heart rates over 200 during a sprint.

I would love to see you succeed, though, I'm pulling for you.

ETA: I had assumed your design would be heavier, but I see you think it will be lighter. I guess we will have to wait for the video if you are not going to post pics.

ynot · 2nd February 2013, 12:41 PM

Originally Posted by Marcus

My bad, I should have paid closer attention.

No worries.

Originally Posted by Marcus

I'm not so sure using rowers instead of cyclists will improve the strength to weight ratio, many of the top cyclists are already running heart rates over 200 during a sprint.

The power to weight ratio of a particular person is what it is regardless of whether it’s applied to pedalling or rowing. For this particular HPH competition that only requires a straight up and down flight for 60 seconds I don’t think pedalling is the best method to use. My whole attempt is based on this belief and if I’m wrong I will fail.

Originally Posted by Marcus

I would love to see you succeed, though, I'm pulling for you.

Thanks.

Originally Posted by Marcus

ETA: I had assumed your design would be heavier, but I see you think it will be lighter.

That‘s my conclusion from what I‘ve developed so far. When I’ve completely built a design I‘m please with I will give the exact weight. Remember what I‘m talking about doesn't include the wings yet.

Originally Posted by Marcus

I guess we will have to wait for the video if you are not going to post pics.

If you were in my position would you publicly post exact and complete details of every unique, innovative, deluded idea you were spending time and money on developing? Remember I’ve only been actively at this for a few weeks and don‘t have anything I can call a final design to post pics of yet anyway. Video at 6:00

.

ynot · 2nd February 2013, 12:56 PM

Here’s a basic concept pic of an earlier design that has been improved . . .

chopperX.jpg

Marcus · 2nd February 2013, 03:58 PM

While we are waiting for the engineers to chime in, perhaps you won't mind some more amateurish questions.

This twin rotor design is more ascetically pleasing than the 4 rotor designs. You'd think that smaller blades (a few meters?) turning at a greater rpm, perhaps with adjustable pitch, would be the ticket. Yet, someone must have done the calculations and decided that those gymnasium filling machines were the best options. Have you done some computer simulations of the performance of your designs? It's not that big of a deal these days, a regular PC could do it.

ynot · 2nd February 2013, 04:32 PM

Originally Posted by Marcus

While we are waiting for the engineers to chime in, perhaps you won't mind some more amateurish questions.

This twin rotor design is more ascetically pleasing than the 4 rotor designs. You'd think that smaller blades (a few meters?) turning at a greater rpm, perhaps with adjustable pitch, would be the ticket. Yet, someone must have done the calculations and decided that those gymnasium filling machines were the best options. Have you done some computer simulations of the performance of your designs? It's not that big of a deal these days, a regular PC could do it.

For human power I think bigger and slower wings are better than small and fast. The Yuri design used by Gamera and Atlas have as much wing area as close to the ground as possible to maximise the advantage of ground effect. Trouble is this advantage all but disappears before you get to the 3 metres height required. Not sure how many wings per set my design will have but it could be as many as six. Not working on wings yet other than a collection of possible ideas. I tend do do practical building and testing rather than theoretical.

tsig · 3rd February 2013, 05:04 AM

Originally Posted by ynot

For human power I think bigger and slower wings are better than small and fast. The Yuri design used by Gamera and Atlas have as much wing area as close to the ground as possible to maximise the advantage of ground effect. Trouble is this advantage all but disappears before you get to the 3 metres height required. Not sure how many wings per set my design will have but it could be as many as six. Not working on wings yet other than a collection of possible ideas. I tend do do practical building and testing rather than theoretical.

I am wondering about the feasibility of having two pilots-motors. If one person can't generate enough force to lift themselves how can two since with two you're doubling the weight, yes you're doubling the power but since the original 'engine' could provide enough energy then why would two?

Did the multi rotor design happen solely because of ground effect or also because it's hard to build one wing that's theoretically big enough while also having enough mechanical robustness?

Good luck, we all pulling for you.

ETA: I see where the counter rotating problem might dictate at least two 'mains'.

tsig · 3rd February 2013, 05:14 AM

Originally Posted by ynot

Here’s a basic concept pic of an earlier design that has been improved . . .

Attachment 27557

I like the direct drive for it's simplicity but I wonder about the required rotor RPM matching the human output.

Marcus · 3rd February 2013, 09:30 AM

Originally Posted by tsig

I like the direct drive for it's simplicity but I wonder about the required rotor RPM matching the human output.

That's where variable pitch would come in handy.

TjW · 3rd February 2013, 09:52 AM

I think human-powered helicopters are a little too marginal to use variable pitch for impedance matching.
Ideally, you'd like for the entire rotor blade to be at the max L/D angle of attack. Any other AOA requires more power input for the same amount of lift.
I think instead you'd be better off to scale the rotor length so the load matches the power source.

Marcus · 3rd February 2013, 10:25 AM

Okay, but he better know how much combined power his athletes are going to be producing on the day.

AmishmanDan · 3rd February 2013, 10:25 AM

Originally Posted by ynot

Don’t really have anything built enough at this stage to provide any pics of. I’m also not completely comfortable publishing exact details of everything until it‘s all closer to being completed. Not sure if this is inventors paranoia or there is any real danger that others might borrow my ideas and use them before I do. I appreciate how open some other teams are with their information but they have been working on their attempts for years and are essentially only copying and improving the earlier attempts of others. I’m trying to be as descriptive as I can with words so that anyone with reasonable mechanical ability should be able to get the pic in their mind. Might post some schematic drawings to make general concepts clearer if I get time to draw them.

I know the feeling about the level of sharing details. I haven't wanted to share much until the day of public launch.

Originally Posted by ynot

I had doubts from day one that Dan would ever post any actual details of his rotors/wings. He doesn't have to of course but it seems pointless to start a thread in this section of the forum and just say he has a dream but it hasn't gone well it practice.

Probably best if he doesn’t post details because I don’t think he could take the honest feedback he would get. He would call it something different.

ynot · 3rd February 2013, 11:52 AM

Originally Posted by tsig

I am wondering about the feasibility of having two pilots-motors. If one person can't generate enough force to lift themselves how can two since with two you're doubling the weight, yes you're doubling the power but since the original 'engine' could provide enough energy then why would two?

Did the multi rotor design happen solely because of ground effect or also because it's hard to build one wing that's theoretically big enough while also having enough mechanical robustness?

Good luck, we all pulling for you.

ETA: I see where the counter rotating problem might dictate at least two 'mains'.

I’m assuming with this design that each pilot could independently power and fly with one of the wing-sets. In other words as if it were two separate choppers. If one pilot could get of the ground with one wing-set then two pilots should be able to with two wing-sets. As both pilots share the weight of the fame it should be slightly better than as if it were two separate choppers. If I‘m wrong it won‘t fly.

tsig · 3rd February 2013, 11:53 AM

Originally Posted by TjW

I think human-powered helicopters are a little too marginal to use variable pitch for impedance matching.
Ideally, you'd like for the entire rotor blade to be at the max L/D angle of attack. Any other AOA requires more power input for the same amount of lift.
I think instead you'd be better off to scale the rotor length so the load matches the power source.

Would you vary the angle of attack along the blade since the tip if the blade moves much faster than the base?

tsig · 3rd February 2013, 12:02 PM

Originally Posted by ynot

I’m assuming with this design that each pilot could independently power and fly with one of the wing-sets. In other words as if it were two separate choppers. If one pilot could get of the ground with one wing-set then two pilots should be able to with two wing-sets. As both pilots share the weight of the fame it should be slightly better than as if it were two separate choppers. If I‘m wrong it won‘t fly.

If one pilot can do the job doesn't two pilots just double your trouble?

ynot · 3rd February 2013, 12:02 PM

Originally Posted by tsig

I like the direct drive for it's simplicity but I wonder about the required rotor RPM matching the human output.

The current main contenders have a wing speed of around 1 revolution per 5-6 seconds. I’m planning on having larger wing areas (more like plane wings) that may give enough lift at an even slower speed. How many RPS you need also obviously depends on how long the wings are. Given the direct transfer of the human power from all limbs for most of the time with this method I think more lift will be able to be generated per pilot than other designs.

TjW · 3rd February 2013, 12:04 PM

It might work that way. But I suspect that the pilot will be the least-optimized part of the helicopter, and that keeping the percentage of non-optimal parts to a minimum is the better strategy.

ynot · 3rd February 2013, 12:09 PM

Originally Posted by tsig

If one pilot can do the job doesn't two pilots just double your trouble?

Two pilots save some weight by sharing the same frame and they provide a human "differential” to provide direct drive counter-rotation (no gears, pulleys, chains, etc). It’s also easier to balance two pilots than one for this direct drive system.

ynot · 3rd February 2013, 12:10 PM

Originally Posted by TjW

I think human-powered helicopters are a little too marginal to use variable pitch for impedance matching.
Ideally, you'd like for the entire rotor blade to be at the max L/D angle of attack. Any other AOA requires more power input for the same amount of lift.
I think instead you'd be better off to scale the rotor length so the load matches the power source.

I agree.

ynot · 3rd February 2013, 12:12 PM

Originally Posted by tsig

Would you vary the angle of attack along the blade since the tip if the blade moves much faster than the base?

Don't know what I will do until I get the the wings stage. Then I will do the simplest thing that works.

26th January 2013, 05:41 PM	#201
ynot Illuminator Join Date: Jan 2006 Location: New Zealand Posts: 4,654	Video of the Atlas Team's 30 second, five feet flight - http://www.youtube.com/watch?v=hm8Lv...ature=youtu.be Some more info here - http://www.aerovelo.com/2013/01/26/p...ng-very-close/ Would like to see video of the failed prize attempt flight. Is anyone else still interested or am I just talking to myself here?
	__________________ Rumours of a god’s existence have been greatly exaggerated. My post are all (IMO) unless stated otherwise. Last edited by ynot; 26th January 2013 at 05:43 PM.

26th January 2013, 08:27 PM	#204
Myriad Hyperthetical Moderator Join Date: Nov 2006 Posts: 8,203	Originally Posted by ynot Video of the Atlas Team's 30 second, five feet flight - http://www.youtube.com/watch?v=hm8Lv...ature=youtu.be Some more info here - http://www.aerovelo.com/2013/01/26/p...ng-very-close/ Wow, that thing is huge. It took me a while to visually parse the photograph; things that I thought at first were parts of the building are actually parts of the vehicle, and vice versa. Interesting that they went with a giant quadrotor. That pyramid of long support trusses must have a high cost in weight and power distribution issues, so the design must have some really big upsides to be worth it. Quote: Is anyone else still interested or am I just talking to myself here? Interested. Respectfully, Myriad
	__________________ The cosmos is a vast Loom, with time the warp and space the weft. We are all fruit of the Loom, unaware.

26th January 2013, 08:33 PM	#205
ynot Illuminator Join Date: Jan 2006 Location: New Zealand Posts: 4,654	Originally Posted by Mister Earl Definitely interested. I keep thinking of ways to do it myself. Hehe. But not being an engineer, I don't have a realistic dog in this fight. My participation is theoretical. My interest in this challenge is not. Great - I'll keep rambling on then.
	__________________ Rumours of a god’s existence have been greatly exaggerated. My post are all (IMO) unless stated otherwise.

26th January 2013, 08:39 PM	#206
ynot Illuminator Join Date: Jan 2006 Location: New Zealand Posts: 4,654	Originally Posted by Marcus Two things strike me about this flight. First is that their design is not able to absorb the full power of their pilot, for the reasons they stated, and the second is that they are not using an optimal power plant. I wonder what someone could do with a world class climber or sprinter at the pedals coupled with a machine that could take the power. Even before their prize attempt I thought it was maybe more to do with publicity for fundraising purposes rather than a serious attempt at winning. If nothing else the Atlas Team are by far the best at fundraising. I don't see 30 secs and 5 ft as being as "close" as they claim. Gamera have done better and I don't think even they can claim to be "close".
	__________________ Rumours of a god’s existence have been greatly exaggerated. My post are all (IMO) unless stated otherwise.

26th January 2013, 08:43 PM	#207
ynot Illuminator Join Date: Jan 2006 Location: New Zealand Posts: 4,654	Originally Posted by Myriad Wow, that thing is huge. It took me a while to visually parse the photograph; things that I thought at first were parts of the building are actually parts of the vehicle, and vice versa. Interesting that they went with a giant quadrotor. That pyramid of long support trusses must have a high cost in weight and power distribution issues, so the design must have some really big upsides to be worth it. Very similar design to the more successful Gamera - http://www.agrc.umd.edu/gamera/index.html Both are copies if the earlier (1994) Yuri - http://www.youtube.com/watch?v=caHCb...ture=endscreen Originally Posted by Myriad Interested. Respectfully, Myriad Great.
	__________________ Rumours of a god’s existence have been greatly exaggerated. My post are all (IMO) unless stated otherwise.

26th January 2013, 06:10 PM	#202
Mister Earl Master Poster Join Date: Nov 2007 Posts: 2,138	Definitely interested. I keep thinking of ways to do it myself. Hehe. But not being an engineer, I don't have a realistic dog in this fight. My participation is theoretical. My interest in this challenge is not.

26th January 2013, 07:35 PM	#203
Marcus Graduate Poster Join Date: Feb 2007 Location: Austin Posts: 1,841	Originally Posted by ynot Video of the Atlas Team's 30 second, five feet flight - http://www.youtube.com/watch?v=hm8Lv...ature=youtu.be Some more info here - http://www.aerovelo.com/2013/01/26/p...ng-very-close/ Would like to see video of the failed prize attempt flight. Is anyone else still interested or am I just talking to myself here? Two things strike me about this flight. First is that their design is not able to absorb the full power of their pilot, for the reasons they stated, and the second is that they are not using an optimal power plant. I wonder what someone could do with a world class climber or sprinter at the pedals coupled with a machine that could take the power.

26th January 2013, 09:17 PM	#208
ynot Illuminator Join Date: Jan 2006 Location: New Zealand Posts: 4,654	Originally Posted by Myriad That pyramid of long support trusses must have a high cost in weight and power distribution issues, so the design must have some really big upsides to be worth it. The design allows all wings to be close to the ground to begin with to gain an advantage from ground effect. Trouble is that advantage all but disappears before you get to the required 3 metres height.
	__________________ Rumours of a god’s existence have been greatly exaggerated. My post are all (IMO) unless stated otherwise.

28th January 2013, 05:32 AM	#209
Marcus Graduate Poster Join Date: Feb 2007 Location: Austin Posts: 1,841	ynot, I've been looking through the videos you've posted on this thread and I was wondering. Has anyone tried a really well done single prop made with advanced composites, a drive train optimized to reduce friction, and a sprinter who can put out 1500 watts for short periods of time? Or is it really just impossible without using these giant 4 prop designs?

28th January 2013, 09:55 AM	#210
CynicalSkeptic Graduate Poster Join Date: Oct 2006 Location: state of denial Posts: 1,367	Originally Posted by ynot Great - I'll keep rambling on then. Also interested. Have little to contribute, but I've been fascinated with the videos I've seen as well as what I've read here.

28th January 2013, 10:50 AM	#211
ynot Illuminator Join Date: Jan 2006 Location: New Zealand Posts: 4,654	Originally Posted by Marcus ynot, I've been looking through the videos you've posted on this thread and I was wondering. Has anyone tried a really well done single prop made with advanced composites, a drive train optimized to reduce friction, and a sprinter who can put out 1500 watts for short periods of time? Or is it really just impossible without using these giant 4 prop designs? There have been a few but counter-rotation is always a problem with a single rotor set. To have a tail rotor that doesn’t provide lift is a waste of energy you don’t have enough of to begin with. So most use multiple counter-rotating or off-set rotor sets. The Upturn uses one set of rotors that are self-rotated with props at the ends of the rotors so no counter-rotation is created.- http://www.ntsworks.com/New_Helicopter.html The Da Vinci had some sort of prop (not at a tail) but it didn’t stop it from counter rotating. I think this was the first HPH to ever get off the ground (I could be wrong) - http://www.youtube.com/watch?v=vYmF7-JWCVA I Haven’t seen any HPH attempt that uses two pilots so if nothing else my attempt would at least be original (no prize for that tho). My design uses two coaxial, counter-rotating wing-sets and the power of the pilots is applied directly to the wings so there is essentially no drive train.
	__________________ Rumours of a god’s existence have been greatly exaggerated. My post are all (IMO) unless stated otherwise. Last edited by ynot; 28th January 2013 at 10:56 AM.

28th January 2013, 10:56 AM	#212
ynot Illuminator Join Date: Jan 2006 Location: New Zealand Posts: 4,654	Originally Posted by CynicalSkeptic Also interested. Have little to contribute, but I've been fascinated with the videos I've seen as well as what I've read here. Thanks. I guess that this thread has had over 5,000 views should be an indication that some people are interested even if they aren’t posting.
	__________________ Rumours of a god’s existence have been greatly exaggerated. My post are all (IMO) unless stated otherwise. Last edited by ynot; 28th January 2013 at 10:59 AM.

31st January 2013, 11:30 AM	#213
CriticalThanking Designated Hitter Join Date: Jan 2006 Location: In the queue to Williamsport Posts: 2,159	[delurk] Interested. I hear Lance Armstrong may be available. I didn't see anything in the rule set about doping. [/delurk]
	__________________ T-Mobile customer service sucks. Happiness should not be a zero sum game. Did I mention T-Mobile customer service sucks?

31st January 2013, 12:53 PM	#214
ynot Illuminator Join Date: Jan 2006 Location: New Zealand Posts: 4,654	Originally Posted by CriticalThanking [delurk] Interested. I hear Lance Armstrong may be available. I didn't see anything in the rule set about doping. [/delurk] Sorry but the rules state . . . "4.2.3 No drugs or stimulants shall be used by any member of the crew. An assurance must be given to the official observers at the time of the attempt that this requirement has been met." Lance could try lying of course.
	__________________ Rumours of a god’s existence have been greatly exaggerated. My post are all (IMO) unless stated otherwise. Last edited by ynot; 31st January 2013 at 12:54 PM.

1st February 2013, 05:11 AM	#215
Marcus Graduate Poster Join Date: Feb 2007 Location: Austin Posts: 1,841	Maybe you could get Mark Cavendish to do it. A world record with a nice vacation in New Zealand, why not.

1st February 2013, 11:53 AM	#216
ynot Illuminator Join Date: Jan 2006 Location: New Zealand Posts: 4,654	Originally Posted by Marcus Maybe you could get Mark Cavendish to do it. A world record with a nice vacation in New Zealand, why not. My design uses two pilots so does Mark have a twin brother? It also uses more of a rowing action not pedalling so perhaps top rowers would be a better choice. NZ just happens to have quite a few world class rowers. Of course my design will be so effective and efficient any two reasonably light, strong and fit people will do the job (what, me deluded?) .
	__________________ Rumours of a god’s existence have been greatly exaggerated. My post are all (IMO) unless stated otherwise.

1st February 2013, 12:06 PM	#217
ynot Illuminator Join Date: Jan 2006 Location: New Zealand Posts: 4,654	I’m building my frame and transmission but every time I think I have a final design and get half way through building it I think of some improvement and have to start over. Hope this time I will get it completed but I don‘t mind delays for improvements. Although I‘m using low-tech aluminium and some bike bit’s I’m confident that the frame/transmission is going to be lighter per pilot than any other design I‘ve seen. Maybe even lighter regardless. Did I mention it will also be more effective and efficient? Oh yes I did
	__________________ Rumours of a god’s existence have been greatly exaggerated. My post are all (IMO) unless stated otherwise. Last edited by ynot; 1st February 2013 at 12:10 PM.

1st February 2013, 12:22 PM	#218
tsig a carbon based life-form Join Date: Nov 2005 Posts: 26,783	Originally Posted by ynot Thanks. I guess that this thread has had over 5,000 views should be an indication that some people are interested even if they aren’t posting. Interested just don't have much to contribute so I lurk.

1st February 2013, 12:23 PM	#219
tsig a carbon based life-form Join Date: Nov 2005 Posts: 26,783	Originally Posted by ynot I’m building my frame and transmission but every time I think I have a final design and get half way through building it I think of some improvement and have to start over. Hope this time I will get it completed but I don‘t mind delays for improvements. Although I‘m using low-tech aluminium and some bike bit’s I’m confident that the frame/transmission is going to be lighter per pilot than any other design I‘ve seen. Maybe even lighter regardless. Did I mention it will also be more effective and efficient? Oh yes I did Pics? Please.

1st February 2013, 12:57 PM	#220
ynot Illuminator Join Date: Jan 2006 Location: New Zealand Posts: 4,654	Design change update . . . I’ve changed the action of the pilots from what I’ve previously explained. To begin with I had the two pilots applying their energy (push/pulls) directly against each other (pilot to pilot) to prevent counter-rotation. This would’ve required the energy of both pilots to be constantly equally and oppositely balanced. I didn’t think this would have been much of a problem to achieve but others did. I’m now using more of a rowing action and each pilot will be pulling with their arms against a push with their legs so the opposing forces cancel each other out in a counter-rotation sense. The actions of the pilots are now independent of each other and as one is “resetting” the other is “powering” so there always a constant application of energy to the wings. As the reset stroke is much faster then the power stroke most of the time both are on the power stroke. Previously each pilot moved one wing-set each but now they both move both. The pilots aren’t on sliding seats as with rowing as this would require them to be wasting energy moving their body weight and would also create more overall imbalance. They are now both sitting upright which is possibly more ergonomic than the previous up-down configuration. So now the overall design is - Two coaxial counter-rotating wing-sets with two pilots positioned below them. The pilots use independent rowing actions to provide the power.
	__________________ Rumours of a god’s existence have been greatly exaggerated. My post are all (IMO) unless stated otherwise. Last edited by ynot; 1st February 2013 at 01:05 PM.

1st February 2013, 01:30 PM	#221
ynot Illuminator Join Date: Jan 2006 Location: New Zealand Posts: 4,654	Originally Posted by tsig Pics? Please. Don’t really have anything built enough at this stage to provide any pics of. I’m also not completely comfortable publishing exact details of everything until it‘s all closer to being completed. Not sure if this is inventors paranoia or there is any real danger that others might borrow my ideas and use them before I do. I appreciate how open some other teams are with their information but they have been working on their attempts for years and are essentially only copying and improving the earlier attempts of others. I’m trying to be as descriptive as I can with words so that anyone with reasonable mechanical ability should be able to get the pic in their mind. Might post some schematic drawings to make general concepts clearer if I get time to draw them.
	__________________ Rumours of a god’s existence have been greatly exaggerated. My post are all (IMO) unless stated otherwise. Last edited by ynot; 1st February 2013 at 01:45 PM.

2nd February 2013, 05:35 AM	#222
Marcus Graduate Poster Join Date: Feb 2007 Location: Austin Posts: 1,841	Originally Posted by ynot My design uses two pilots so does Mark have a twin brother? It also uses more of a rowing action not pedalling so perhaps top rowers would be a better choice. NZ just happens to have quite a few world class rowers. Of course my design will be so effective and efficient any two reasonably light, strong and fit people will do the job (what, me deluded?) . My bad, I should have paid closer attention. I'm not so sure using rowers instead of cyclists will improve the strength to weight ratio, many of the top cyclists are already running heart rates over 200 during a sprint. I would love to see you succeed, though, I'm pulling for you. ETA: I had assumed your design would be heavier, but I see you think it will be lighter. I guess we will have to wait for the video if you are not going to post pics.
	Last edited by Marcus; 2nd February 2013 at 05:41 AM.

2nd February 2013, 12:41 PM	#223
ynot Illuminator Join Date: Jan 2006 Location: New Zealand Posts: 4,654	Originally Posted by Marcus My bad, I should have paid closer attention. No worries. Originally Posted by Marcus I'm not so sure using rowers instead of cyclists will improve the strength to weight ratio, many of the top cyclists are already running heart rates over 200 during a sprint. The power to weight ratio of a particular person is what it is regardless of whether it’s applied to pedalling or rowing. For this particular HPH competition that only requires a straight up and down flight for 60 seconds I don’t think pedalling is the best method to use. My whole attempt is based on this belief and if I’m wrong I will fail. Originally Posted by Marcus I would love to see you succeed, though, I'm pulling for you. Thanks. Originally Posted by Marcus ETA: I had assumed your design would be heavier, but I see you think it will be lighter. That‘s my conclusion from what I‘ve developed so far. When I’ve completely built a design I‘m please with I will give the exact weight. Remember what I‘m talking about doesn't include the wings yet. Originally Posted by Marcus I guess we will have to wait for the video if you are not going to post pics. If you were in my position would you publicly post exact and complete details of every unique, innovative, deluded idea you were spending time and money on developing? Remember I’ve only been actively at this for a few weeks and don‘t have anything I can call a final design to post pics of yet anyway. Video at 6:00 .
	__________________ Rumours of a god’s existence have been greatly exaggerated. My post are all (IMO) unless stated otherwise. Last edited by ynot; 2nd February 2013 at 12:53 PM.

2nd February 2013, 12:56 PM	#224
ynot Illuminator Join Date: Jan 2006 Location: New Zealand Posts: 4,654	Here’s a basic concept pic of an earlier design that has been improved . . . chopperX.jpg
	__________________ Rumours of a god’s existence have been greatly exaggerated. My post are all (IMO) unless stated otherwise.

2nd February 2013, 03:58 PM	#225
Marcus Graduate Poster Join Date: Feb 2007 Location: Austin Posts: 1,841	While we are waiting for the engineers to chime in, perhaps you won't mind some more amateurish questions. This twin rotor design is more ascetically pleasing than the 4 rotor designs. You'd think that smaller blades (a few meters?) turning at a greater rpm, perhaps with adjustable pitch, would be the ticket. Yet, someone must have done the calculations and decided that those gymnasium filling machines were the best options. Have you done some computer simulations of the performance of your designs? It's not that big of a deal these days, a regular PC could do it.

2nd February 2013, 04:32 PM	#226
ynot Illuminator Join Date: Jan 2006 Location: New Zealand Posts: 4,654	Originally Posted by Marcus While we are waiting for the engineers to chime in, perhaps you won't mind some more amateurish questions. This twin rotor design is more ascetically pleasing than the 4 rotor designs. You'd think that smaller blades (a few meters?) turning at a greater rpm, perhaps with adjustable pitch, would be the ticket. Yet, someone must have done the calculations and decided that those gymnasium filling machines were the best options. Have you done some computer simulations of the performance of your designs? It's not that big of a deal these days, a regular PC could do it. For human power I think bigger and slower wings are better than small and fast. The Yuri design used by Gamera and Atlas have as much wing area as close to the ground as possible to maximise the advantage of ground effect. Trouble is this advantage all but disappears before you get to the 3 metres height required. Not sure how many wings per set my design will have but it could be as many as six. Not working on wings yet other than a collection of possible ideas. I tend do do practical building and testing rather than theoretical.
	__________________ Rumours of a god’s existence have been greatly exaggerated. My post are all (IMO) unless stated otherwise. Last edited by ynot; 2nd February 2013 at 04:37 PM.

3rd February 2013, 05:04 AM	#227
tsig a carbon based life-form Join Date: Nov 2005 Posts: 26,783	Originally Posted by ynot For human power I think bigger and slower wings are better than small and fast. The Yuri design used by Gamera and Atlas have as much wing area as close to the ground as possible to maximise the advantage of ground effect. Trouble is this advantage all but disappears before you get to the 3 metres height required. Not sure how many wings per set my design will have but it could be as many as six. Not working on wings yet other than a collection of possible ideas. I tend do do practical building and testing rather than theoretical. I am wondering about the feasibility of having two pilots-motors. If one person can't generate enough force to lift themselves how can two since with two you're doubling the weight, yes you're doubling the power but since the original 'engine' could provide enough energy then why would two? Did the multi rotor design happen solely because of ground effect or also because it's hard to build one wing that's theoretically big enough while also having enough mechanical robustness? Good luck, we all pulling for you. ETA: I see where the counter rotating problem might dictate at least two 'mains'.
	Last edited by tsig; 3rd February 2013 at 05:07 AM.

3rd February 2013, 05:14 AM	#228
tsig a carbon based life-form Join Date: Nov 2005 Posts: 26,783	Originally Posted by ynot Here’s a basic concept pic of an earlier design that has been improved . . . Attachment 27557 I like the direct drive for it's simplicity but I wonder about the required rotor RPM matching the human output.

3rd February 2013, 09:30 AM	#229
Marcus Graduate Poster Join Date: Feb 2007 Location: Austin Posts: 1,841	Originally Posted by tsig I like the direct drive for it's simplicity but I wonder about the required rotor RPM matching the human output. That's where variable pitch would come in handy.

3rd February 2013, 09:52 AM	#230
TjW Philosopher Join Date: Mar 2005 Location: up in the air Posts: 9,999	I think human-powered helicopters are a little too marginal to use variable pitch for impedance matching. Ideally, you'd like for the entire rotor blade to be at the max L/D angle of attack. Any other AOA requires more power input for the same amount of lift. I think instead you'd be better off to scale the rotor length so the load matches the power source.
	__________________ TjW People like TjW -- Kelly

3rd February 2013, 10:25 AM	#231
Marcus Graduate Poster Join Date: Feb 2007 Location: Austin Posts: 1,841	Okay, but he better know how much combined power his athletes are going to be producing on the day.
	Last edited by Marcus; 3rd February 2013 at 10:27 AM.

3rd February 2013, 10:25 AM	#232
AmishmanDan Scholar Join Date: Dec 2012 Posts: 64	Originally Posted by ynot Don’t really have anything built enough at this stage to provide any pics of. I’m also not completely comfortable publishing exact details of everything until it‘s all closer to being completed. Not sure if this is inventors paranoia or there is any real danger that others might borrow my ideas and use them before I do. I appreciate how open some other teams are with their information but they have been working on their attempts for years and are essentially only copying and improving the earlier attempts of others. I’m trying to be as descriptive as I can with words so that anyone with reasonable mechanical ability should be able to get the pic in their mind. Might post some schematic drawings to make general concepts clearer if I get time to draw them. I know the feeling about the level of sharing details. I haven't wanted to share much until the day of public launch. Originally Posted by ynot I had doubts from day one that Dan would ever post any actual details of his rotors/wings. He doesn't have to of course but it seems pointless to start a thread in this section of the forum and just say he has a dream but it hasn't gone well it practice. Probably best if he doesn’t post details because I don’t think he could take the honest feedback he would get. He would call it something different.
AmishmanDan Scholar Join Date: Dec 2012 Posts: 64

3rd February 2013, 11:52 AM	#233
ynot Illuminator Join Date: Jan 2006 Location: New Zealand Posts: 4,654	Originally Posted by tsig I am wondering about the feasibility of having two pilots-motors. If one person can't generate enough force to lift themselves how can two since with two you're doubling the weight, yes you're doubling the power but since the original 'engine' could provide enough energy then why would two? Did the multi rotor design happen solely because of ground effect or also because it's hard to build one wing that's theoretically big enough while also having enough mechanical robustness? Good luck, we all pulling for you. ETA: I see where the counter rotating problem might dictate at least two 'mains'. I’m assuming with this design that each pilot could independently power and fly with one of the wing-sets. In other words as if it were two separate choppers. If one pilot could get of the ground with one wing-set then two pilots should be able to with two wing-sets. As both pilots share the weight of the fame it should be slightly better than as if it were two separate choppers. If I‘m wrong it won‘t fly.
	__________________ Rumours of a god’s existence have been greatly exaggerated. My post are all (IMO) unless stated otherwise.

3rd February 2013, 11:53 AM	#234
tsig a carbon based life-form Join Date: Nov 2005 Posts: 26,783	Originally Posted by TjW I think human-powered helicopters are a little too marginal to use variable pitch for impedance matching. Ideally, you'd like for the entire rotor blade to be at the max L/D angle of attack. Any other AOA requires more power input for the same amount of lift. I think instead you'd be better off to scale the rotor length so the load matches the power source. Would you vary the angle of attack along the blade since the tip if the blade moves much faster than the base?

3rd February 2013, 12:02 PM	#235
tsig a carbon based life-form Join Date: Nov 2005 Posts: 26,783	Originally Posted by ynot I’m assuming with this design that each pilot could independently power and fly with one of the wing-sets. In other words as if it were two separate choppers. If one pilot could get of the ground with one wing-set then two pilots should be able to with two wing-sets. As both pilots share the weight of the fame it should be slightly better than as if it were two separate choppers. If I‘m wrong it won‘t fly. If one pilot can do the job doesn't two pilots just double your trouble?