Another Friday flying machine/engineering thread

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1

Oh. My. OK, so after the Giant Robot… this next, yehr? :slight_smile:
Jon “The Nice Guy” Spriggs LPIC-1 CertifiedFrom: XRobots xrobots@gmail.com
Date: 2009/8/10
Subject: [Southackton] Re: Another Friday flying machine/engineering thread
To: SoutHACKton southackton@googlegroups.com

Related but terrifying:

Does anyone remember seeing this in the news a while ago:

http://www.metro.co.uk/weird/article.html?in_article_id=22187&in_page...http://www.theregister.co.uk/2006/10/24/giant_model_plane/http://www.wmin.ac.uk/mad/page-1524

…it was obviously a ludicrous thing to try, and if it had actually
got any lift I’ve now idea how on earth he was hoping to control it
rather than just nose diving and killing himself.

Then I was looking for jet pack info in relation to my ‘bottle rocket
jet pack’ idea, and came across this:

http://www.youtube.com/watch?v=vyb6vnX1My0

The basic spec is:

-Two 1.7ft diameter ducted fans, peaking at about 7000 rpm.
-A 2 litre two stroke engine burning 10 gallons an hour.
-Weighs 250 lbs / 112 Kg (17 stone) + the person.

Ducted fans are quite a bit more efficient than a standard propeller:
http://en.wikipedia.org/wiki/Ducted_fan

…so this got me thinking about how much lift you could get from one
or more rubber band/bungee powered ducted fans on that scale. Large
bungees wouldn’t be too hard to make from several parallel bungee
cords together, and if the construction used proper bearings etc you
could probably get up to a fair rpm.

I was thinking about something along the lines of a 5/6ft vertical
stick or tube that has the bungee stretched along its length, with
maybe a 2ft diameter ducted fan at one end. Since there’s no engine or
fuel, so they are each effectively ‘self powered’, you could keep
adding these units until you have enough of them to produce sufficient
lift… maybe four of them with the person somewhere in the lower/
middle.

I guess it wouldn’t take long for the bungee to unwind, maybe a few
seconds of flight / a short jump.

2

Surely a quadcopter version for 4-player fun!2009/8/10 Jon Spriggs jon@spriggs.org.uk

Oh. My. OK, so after the Giant Robot… this next, yehr? :slight_smile:

Jon “The Nice Guy” Spriggs LPIC-1 Certified

---------- Forwarded message ----------
From: XRobots xrobots@gmail.com
Date: 2009/8/10
Subject: [Southackton] Re: Another Friday flying machine/engineering thread
To: SoutHACKton southackton@googlegroups.com

Related but terrifying:

http://www.wired.com/gadgetlab/2009/08/chinese-farmer-builds-his-own-flying-machine/

On Aug 7, 9:45 am, XRobots xrob...@gmail.com wrote:

Does anyone remember seeing this in the news a while ago:

http://www.metro.co.uk/weird/article.html?in_article_id=22187&in_page...http://www.theregister.co.uk/2006/10/24/giant_model_plane/http://www.wmin.ac.uk/mad/page-1524

…it was obviously a ludicrous thing to try, and if it had actually
got any lift I’ve now idea how on earth he was hoping to control it
rather than just nose diving and killing himself.

Then I was looking for jet pack info in relation to my ‘bottle rocket
jet pack’ idea, and came across this:

http://www.youtube.com/watch?v=vyb6vnX1My0

The basic spec is:

-Two 1.7ft diameter ducted fans, peaking at about 7000 rpm.
-A 2 litre two stroke engine burning 10 gallons an hour.
-Weighs 250 lbs / 112 Kg (17 stone) + the person.

Ducted fans are quite a bit more efficient than a standard propeller:
http://en.wikipedia.org/wiki/Ducted_fan

…so this got me thinking about how much lift you could get from one
or more rubber band/bungee powered ducted fans on that scale. Large
bungees wouldn’t be too hard to make from several parallel bungee
cords together, and if the construction used proper bearings etc you
could probably get up to a fair rpm.

I was thinking about something along the lines of a 5/6ft vertical
stick or tube that has the bungee stretched along its length, with
maybe a 2ft diameter ducted fan at one end. Since there’s no engine or
fuel, so they are each effectively ‘self powered’, you could keep
adding these units until you have enough of them to produce sufficient
lift… maybe four of them with the person somewhere in the lower/
middle.

I guess it wouldn’t take long for the bungee to unwind, maybe a few
seconds of flight / a short jump.