Acendedor de Churrascada, Electricidade mais barata, um Modelo de Hovercraft, uma Sanfona em Papel, e mais rodas Dentadas

Alô, Brasil! 

Uma notícia, cortesia do nosso Amigo Inventor, José Abrahão, cá vai uma Engenhoca para chamar as atenções, para as vossas Chrrascadas ao ar livre...

À Engenhocas! MUÁHÁHÁHÁ!

Também dará para afugentar Onças, mas não tenho a certeza... 
Agora que penso nisso, todos os Cineastas e Cenógrafos de Fim-de-semana, mais as Escolas de Samba, Festas Tradicionais, etc. poderão usar isto como adereço, nas suas Obras de Arte ao vivo, com as devidas e indispensáveis Medidas de Segurança.

Moose/Bear Repellent aka FLAME THROWER

PDRWLSN

The idea for this project was born from trying to get our campfires started with kindling and wood so wet we couldn't get them to burn with dry paper. Sure charcoal lighter would work but where's the fun in that?

Please don't be misled by the term Moose/Bear Repellent, I only used it to create more interest. It probably wouldn't deter a bear that was intent on inflicting harm. If anyone wishes to visit Alaska to enjoy the great outdoors, I would recommend some sort of bear deterrent. Be advised a big ol' can of pepper spray isn't always effective, they have even been seen licking it from the ground. Making plenty of noise or an occasional blast on a portable air horn while you're hiking will keep surprise encounters to a minimum. As for the moose, beware, they usually aren't afraid of anything and would love a chance to bully you for your snacks, or for no reason at all.  
  
http://www.instructables.com/id/MooseBear-Repellent-aka-FLAME-THROWER/

Electricidade a partir da Diferença de Salinidade nos Estuários dos Rios, pode estar mais perto de ser uma realidade práctica, com este avanço no seu até agora fraco rendimento:

Nanotubes boost potential of salinity power as a renewable energy source

Darren Quick

In November 2009, Norwegian state owned electricity company Statkraft opened the world’s first osmotic power plant prototype, which generates electricity from the difference in the salt concentration between river water and sea water. While osmotic power is a clean, renewable energy source, its commercial use has been limited due to the low generating capacities offered by current technology – the Statkraft plant, for example, has a capacity of about 4 kW. Now researchers have discovered a new way to harness osmotic power that they claim would enable a 1 m² (10.7 sq. ft.) membrane to have the same 4 kW capacity as the entire Statkraft plant.

http://www.gizmag.com/osmotic-salinity-gradient-power-nanotubes/26623/

E algo para alegrar a Malta, um impecável Hovercraft Tele-comandado, a partir de meia-dúzia de Materiais, ora aqui está algo para ter uma desculpa para passar uns momentos ao Ar livre...

How to make a RC Hovercraft  

sjors073

A while ago I posted an instructable of my radio controlled hovercraft, which you can see here:
http://www.instructables.com/id/RC-Hovercraft/

I hope you liked it, some of you asked me to make an step by step instructable. I thought that was a good idea and I decided to make one.
In this instructable I will show you how I build my hovercraft, powered by electric motors and controlled by a radio transmitter. I hope you learn from it so you can make it too.

http://www.instructables.com/id/How-to-make-a-RC-Hovercraft/

Rob Ives volta a surpreender-nos com esta Sanfona em Papel, se algo existe de interesse, por aí, ele vai, e faz uma versão em Papel!

Make Your Own Paper Squeeze Box Accordion

A working paper squeeze box accordion to print out and make. It only plays two notes but hey, it works and it is made from paper!

Members can download the parts for free as usual, non-members can download the parts file for £2.50 from the link above. The file comes as a coloured and no-coloured version.

http://www.robives.com/blog/squeeze

Este Instructable é engraçado, mas é bem mais do que isso, dá-vos mais uma maneira de fazerem Rodas Dentadas, desta vez, só com alguns cálculos, um Berbequim, e uma Lima:

Geared Candleholder 

tinkertinker

This project is a candleholder with three gears and parallel action arms which move the candles up and down at different rates.It is made from aluminum plate and uses tea lights or small floating candles. The design and the variable gearing make it a playful device.

I Make gears basically by drilling holes in a circle, and then cutting away excess material so that the holes become the "valleys" between teeth. The diameter of the circle that passes through the center of each tooth (the Pitch Circle), is calculated by the formula shown below.

Also note the additional holes marked "#25". These are mounting holes for the connecting rods that join to the parallel arms. They need to be drilled with a #25 drill bit, and then tapped with a 10-24 tap to accept the shoulder bolts that act as pivots for the connecting arms.

http://www.instructables.com/id/Geared-Candleholder/