Welcome! Log In Create A New Profile


Multipurpose Plug-n-Spin Hand-Crank with replaceable gear mechanism

Posted by Kartturi 
Multipurpose Plug-n-Spin Hand-Crank with replaceable gear mechanism
June 27, 2009 10:57AM
If one can realistically reprap a hand-crank with a simple gear mechanism
like this:

(See more photos given as FP_*.jpg attachments at the bottom of my
previous posting [forums.reprap.org] )

then one could use it, apart from a manual "food processor",
also in numerous other tools that would make life easier in
many parts of the world.
The following tools come to my mind:

- hand-powered spinning reel?
(See e.g. [en.wikipedia.org] )

- small-scale honey extractor (centrifuge)

- some variant of the butter churn
(see [www.webexhibits.org] )

- fishing reel (maybe not the best choice for tuna or barracuda fishing,
but probably good enough for small catch?
The problem seems to be that normally you need
a reasonable fast spinning rate, but when the
fish catches the bait, you suddenly need some
torque, without gears jamming.)

- even some kind of drill?

- also as a part of hand powered electric generator,
and any other light tool where a simple hand crank with
plastic gear mechanism suffices.

Because making the hand-crank & gears with RepRap would
in any case be expensive (for many of the poor people),
it would make sense to make just one or two of them,
but with some standard modular design, that would
allow them to be used in all of the above tools.
(Just plug-n-spin!)

Also, the design would be OPEN in a very concrete
sense, that one could easily replace the gears, for

a) to get different gear ratios appropriate for different tools/applications,


b) to replace the worn-out gears. (I reckon that the currently
used ABS-plastic wears out more quickly than the nylon used in the
industrially made plastic gears?)

So, if somebody likes this idea, please create a prototype,
and publish it here, before some crook patents it.


Antti Karttunen
Sorry, only registered users may post in this forum.

Click here to login