h a l f b a k e r y
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jump up high and far and slowly glide back down
[edited twice see at end] I just realized the most important
part is missing from
my idea. There is no spring. It's a propeller or quadcopter on
your back, that rather than picking you up and holding you it
only helps you jump high and then land slowly.
Attached to your harness on your back,
some of the upward
energy is given by your jump, with the rest coming from a
yank on the rope/rod extending down from the propeller
which is now airborn a meter above you.
Like a spring it springs into action sending your jump high up
then you slowly come back to the ground for your next hop.
The upward elevation action is only for half a second and
is used to slow you down as you ease back to the ground.
[2nd edit] A better way to do this:
A small LTA Ram-air parafoil (see Parachute on Wikipedia)
that when you jump pulls you up quickly by shortening the
rope. Then lets you down slowly back to the ground. It
should be smaller than a parachute so that if it's windy it
doesn't pull you away.
From Star Wars [notexactly, Jun 20 2019]
Another thing I learned
The Nazis weren't developing jetpacks after all [notexactly, Jun 20 2019]
Even less ambitious approach ...
[normzone, Jul 03 2019]
||A pogo stick with a giant sycamore seed on top?
||How do you re-compress the jumping spring in preparation for the next ascent?
||I suppose you could have some kind of leg-actuated device like a rowing machine, so you could pump up the spring as you are gliding. Then as you touch the ground you can jump again and the spring will release its energy for your next ascent.
||I think this could work very well. The wing folding geometry needs to be very carefully worked out so that the folded wings provide minimum drag on the way up, but snap out to support your glide on the way down.
||If the wings fail, then the yet-to-be-compressed spring should be able to absorb impact forces from an uncontrolled descent.
||No spring in this idea. I realize I wasn't clear about how this
works. I meant only SIMILAR to a spring's action. I thought the
fact that the idea is in the HELICOPTER category was self
explenatory. Please see the newly edited idea.
||Anyway, looking at this idea a second time I have a better way
of accomplishing this. see second edit at the end of the idea.
||Re <link>, the Argus pulsejet - or any other pulsejet - is a very poor fit in the jetpack application as it has a very low specific impulse (hence the steam catapult launch for the V1). But the Germans did have the Walter peroxide rocket technology as used in the Me163, and the Bell jetpack uses peroxide in its fuel system.
||Yes, but the attraction of a pulse-jet as a backpack is that it
enables you to watch someone with a pulse-jet as a backpack.