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#21
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Propeller or jet to push an in-line skater?
I'm trolling?
LOL! Bye now... |
#22
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Propeller or jet to push an in-line skater?
usenet jac.users.panix.com (John Clear) wrote:
John Doe jdoe usenetlove.invalid wrote: How far-fetched is the idea, to use a propeller or jet engine (radio controlled type?) to push an in-line skater? How does aircraft takeoff thrust compare to using a conventional motor and wheel to push oneself along the ground? What sort of incline would be achievable at say a skater weight of about 160 pounds? I think the rolling resistance can be assumed to be zero or maybe the same as a small aircraft. Years ago (maybe late 1990s) one of those 'whacky invention' type TV shows featured a guy with jet engines mounted on the tails of his skis. No need for a chair lift, he'd just ski uphill. Inline skating is like a combination of different sports, including skiing. One unique difference is that in-line skating requires man-made terrain. So it has been done, just make sure your life insurance is paid up. If you wear lots of protective gear and consider the risks, safety should not be a concern. On TV, you see skaters and cyclists who do not wear protective gear, apparently many people enjoy seeing the accidents, but I just change the channel. Carelessly riding a large displacement motorcycle years ago makes anything I do now days pale in comparison. This Still researching the issue, but by the lack of detailed comment, I get the impression that propeller power is nowhere near efficient as conventional motor and wheel on the ground propulsion. That is the question. -- John -- John Clear - jac panix.com http://www.clear-prop.org/ |
#23
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Propeller or jet to push an in-line skater?
cavelamb cavelamb earthlink.net wrote:
I'm trolling? Or just babbling. LOL! "There is someone in my head but it's not me... la la la" Safety depends on how a device is used. And then there is the fact that an unbuilt device poses no safety risk whatsoever. A thoughtful person might consider the possibility of others reading without being cautious, but how is that a concern when you are talking about building something. -- Bye now... |
#24
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Propeller or jet to push an in-line skater?
Just babbling...
Look up gyroscopic precession - torque induced. Might also consider tip speeds, and what happens when props contact things... Oh, and just on a hunch, I've removed Free.usenet group. John Doe wrote: cavelamb cavelamb earthlink.net wrote: I'm trolling? Or just babbling. LOL! "There is someone in my head but it's not me... la la la" Safety depends on how a device is used. And then there is the fact that an unbuilt device poses no safety risk whatsoever. A thoughtful person might consider the possibility of others reading without being cautious, but how is that a concern when you are talking about building something. -- Richard Lamb |
#25
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Propeller or jet to push an in-line skater?
cavelamb cavelamb earthlink.net wrote:
Just babbling... Look up gyroscopic precession - torque induced. Might also consider tip speeds, and what happens when props contact things... So put a cage around it. That is what the example from Australia does. But seriously. A sixth grader could figure out that one. -- Oh, and just on a hunch, I've removed Free.usenet group. John Doe wrote: cavelamb cavelamb earthlink.net wrote: I'm trolling? Or just babbling. LOL! "There is someone in my head but it's not me... la la la" Safety depends on how a device is used. And then there is the fact that an unbuilt device poses no safety risk whatsoever. A thoughtful person might consider the possibility of others reading without being cautious, but how is that a concern when you are talking about building something. -- Richard Lamb Path: news.astraweb.com!border5.newsrouter.astraweb.com! news.glorb.com!news2.glorb.com!Xl.tags.giganews.co m!border1.nntp.dca.giganews.com!nntp.giganews.com! local2.nntp.dca.giganews.com!nntp.earthlink.com!ne ws.earthlink.com.POSTED!not-for-mail NNTP-Posting-Date: Thu, 22 Jul 2010 20:34:56 -0500 Date: Thu, 22 Jul 2010 20:34:31 -0500 From: cavelamb cavelamb earthlink.net User-Agent: Thunderbird 2.0.0.24 (Windows/20100228) MIME-Version: 1.0 Newsgroups: rec.aviation.military,rec.aviation.homebuilt Subject: Propeller or jet to push an in-line skater? References: 4c479785$0$4752$c3e8da3 news.astraweb.com l6OdnXpB6OmOPNrRnZ2dnUVZ_q2dnZ2d giganews.com o_r_fairbairn-E87157.23144421072010 70-3-168-216.pools.spcsdns.net 4c47bb7a$0$8726$c3e8da3 news.astraweb.com _qednaqEVc1sIdrRnZ2dnUVZ_tCdnZ2d earthlink.com obadnZyJBemBXdrRnZ2dnUVZ_jidnZ2d giganews.com 4c47c204$0$9831$c3e8da3 news.astraweb.com 4c4827f6$0$14497$afc38c87 news.optusnet.com.au Xns9DBD59E431D62jyaniklocalnetcom 216.168.3.44 12d84862-6957-4c46-9aee-2701863013ba l14g2000yql.googlegroups.com 4c48a6f2$0$21146$c3e8da3 news.astraweb.com esWdnY4-doRSXtXRnZ2dnUVZ_rednZ2d earthlink.com 4c48c8c8$0$4841$c3e8da3 news.astraweb.com RO6dneSupL7bR9XRnZ2dnUVZ_qWonZ2d earthlink.com 4c48e2a9$0$13681$c3e8da3 news.astraweb.com In-Reply-To: 4c48e2a9$0$13681$c3e8da3 news.astraweb.com Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Message-ID: mbWdnQJBntBdbNXRnZ2dnUVZ_qqdnZ2d earthlink.com Lines: 33 X-Usenet-Provider: http://www.giganews.com NNTP-Posting-Host: 96.18.15.71 X-Trace: sv3-iB4JN3Jj2clFicjdEW43M2GqnwrgluDZzeh7TKimEKWSX1rkoX b4m1cuFff+bPURU1fGQVw8ziJw6vs!H5gHOwW6degAlz9dQHbD sDn8A0OioAP4zqlbu5a3xvFhcBP9fGcd6V13H+d9sUBFFHTu5W THw01j!LocqCfJQ7nGxv5ySMcqyajf6eOmwDOc= X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.40 |
#26
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Propeller or jet to push an in-line skater?
John Doe wrote:
cavelamb cavelamb earthlink.net wrote: Just babbling... Look up gyroscopic precession - torque induced. Might also consider tip speeds, and what happens when props contact things... So put a cage around it. That is what the example from Australia does. But seriously. A sixth grader could figure out that one. And the precession? -- Richard Lamb |
#27
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Propeller or jet to push an in-line skater?
cavelamb cavelamb earthlink.net wrote:
John Doe wrote: cavelamb cavelamb earthlink.net wrote: Just babbling... Look up gyroscopic precession - torque induced. Might also consider tip speeds, and what happens when props contact things... So put a cage around it. That is what the example from Australia does. But seriously. A sixth grader could figure out that one. And the precession? There are dozens of paragliding videos on YouTube using a backpack propeller. Let me know if you see any evidence of that. |
#28
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Propeller or jet to push an in-line skater?
"John Doe" wrote in message ... usenet jac.users.panix.com (John Clear) wrote: John Doe jdoe usenetlove.invalid wrote: How far-fetched is the idea, to use a propeller or jet engine (radio controlled type?) to push an in-line skater? How does aircraft takeoff thrust compare to using a conventional motor and wheel to push oneself along the ground? What sort of incline would be achievable at say a skater weight of about 160 pounds? I think the rolling resistance can be assumed to be zero or maybe the same as a small aircraft. Years ago (maybe late 1990s) one of those 'whacky invention' type TV shows featured a guy with jet engines mounted on the tails of his skis. No need for a chair lift, he'd just ski uphill. Inline skating is like a combination of different sports, including skiing. One unique difference is that in-line skating requires man-made terrain. So it has been done, just make sure your life insurance is paid up. If you wear lots of protective gear and consider the risks, safety should not be a concern. On TV, you see skaters and cyclists who do not wear protective gear, apparently many people enjoy seeing the accidents, but I just change the channel. Carelessly riding a large displacement motorcycle years ago makes anything I do now days pale in comparison. This Still researching the issue, but by the lack of detailed comment, I get the impression that propeller power is nowhere near efficient as conventional motor and wheel on the ground propulsion. That is the question. -- No that is the answer. Keith |
#29
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Propeller or jet to push an in-line skater?
On 23/07/2010 09:01, Keith Willshaw wrote:
"John Doe" wrote in message ... usenet jac.users.panix.com (John Clear) wrote: John Doe jdoe usenetlove.invalid wrote: How far-fetched is the idea, to use a propeller or jet engine (radio controlled type?) to push an in-line skater? How does aircraft takeoff thrust compare to using a conventional motor and wheel to push oneself along the ground? What sort of incline would be achievable at say a skater weight of about 160 pounds? I think the rolling resistance can be assumed to be zero or maybe the same as a small aircraft. Years ago (maybe late 1990s) one of those 'whacky invention' type TV shows featured a guy with jet engines mounted on the tails of his skis. No need for a chair lift, he'd just ski uphill. Inline skating is like a combination of different sports, including skiing. One unique difference is that in-line skating requires man-made terrain. So it has been done, just make sure your life insurance is paid up. If you wear lots of protective gear and consider the risks, safety should not be a concern. On TV, you see skaters and cyclists who do not wear protective gear, apparently many people enjoy seeing the accidents, but I just change the channel. Carelessly riding a large displacement motorcycle years ago makes anything I do now days pale in comparison. This Still researching the issue, but by the lack of detailed comment, I get the impression that propeller power is nowhere near efficient as conventional motor and wheel on the ground propulsion. That is the question. -- No that is the answer. Keith Jet / Propellor / rubber band. It doesnt mallet what the power supply is. Work out where the center of thrust/pull is - Probably if on a skater approx 1.2metres up. When the skater hit a bump to large for the front to quickly rise over, the skater kisses the ground. Think water skiing - It is a challenge to get up o the skiis, and then the second you relax, and let the ski dig it, you are in the water |
#30
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Propeller or jet to push an in-line skater?
Giles Ayling giles tvp.ltd.uk wrote:
Keith Willshaw wrote: "John Doe" wrote in message .... I get the impression that propeller power is nowhere near efficient as conventional motor and wheel on the ground propulsion. That is the question. No that is the answer. Jet / Propellor / rubber band. It doesnt mallet what the power supply is. Are you using speech recognition? Or were you drunk? Just curious. Work out where the center of thrust/pull is - Probably if on a skater approx 1.2metres up. When the skater hit a bump to large for the front to quickly rise over, the skater kisses the ground. Skating is extremely flexible. One way to cope is to step over the obstacle. Another way is by keeping your weight on your rear wheels. And yet another way to cope with larger obstacles is called "scissoring". And of course you can do stuff in combination. If none of the above works, when you hit a bump that radically slows one skate, you can quickly put all of your weight on the other skate and simultaneously steer inwards with that good skate to maintain your balance. You learn to do that stuff without thinking. But, coincidentally, large unexpected obstacles is exactly why I made big front wheel skates, a 140 mm front wheel with 80 mm trailing wheels. Love them and use them for rough street skating regularly. http://www.flickr.com/photos/27532210@N04/3056505603/ http://www.flickr.com/photos/27532210 N04/3056505603/ By the way... If anyone here (young enough to run or at least to remember doing fun things) has never heard of "powered paragliding", check it out! It is (lighter than) ultra light powered flight. Amazing stuff IMO. Dozens of videos on YouTube. -- Think water skiing - It is a challenge to get up o the skiis, and then the second you relax, and let the ski dig it, you are in the water |
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