Firky2010

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LEGO Facts

  • LEGO is an abbreviation of the two Danish words "leg godt", meaning "play well"
  • During the moulding process, the plastic is heated to 232°C until its consistency is that of dough
  • In 2003 LEGO  changed the minifigure's yellow facial colouring to a more authentic skin colour
  • In 2006 the LEGO  website had an average of 8,137,062 individual visitors a month
  • If you built a column of about 40,000,000,000 LEGO bricks, it would reach the moon

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Pneumatic Grab

Here is one of my earlier designs for a grab Using Pneumatic rams to open and close the grab. Pneumatic rams are very strong but unfortunately are bulky and unreliable.  Pipes often blow off at high pressure and you require a compressor to maintain a good air flow.  This was inconvenient for me. Controlling the pneumatics electronically isn't a doddle either but over at www.techbricks.nl there is a number of options for both pneumatic valves and compressors. So, armed with a few ideas I set to work to try and build a light weight grab. The result is shown below in the youtube video. This was the best design I came up with. It was still big and bulky, but light weight. It was the lightest I could build the grab without compromising its strength. 


I was not satisfied with the above design - it didn't look right or feel right and it was very difficult to work with. Controlling all four rams at the same time proved to be a big task. So I spent a few days on youtube and after a few hours of trolling though youtube I found a new design. This design shown below is very advanced with self-adaptive griping and can easily pick up many objects as shown in this video. I felt the need to build this grab to find out more and see if it was worthy enough for my Arm. 


I then spoke to Nino over at www.clicker.com.au who built this grab and for a small fee I was able to get my hands on his design so I could build it for my self to understand how it worked. I was very impressed, and it really did work well. This is the first time I had ever seen self-adaptive griping so I went ahead and built the grab and tested for a few days to see how reliable it was. You can see in the video below my grab built from Nino instructions. I used a few more readily available LEGO pieces but it was basically the same.


After building this grab I found it was much bigger than expected - very heavy. I could tell that it would be very near impossible to build an arm strong enough to lift this grab. This grab also clashed with one of my main objectives "360 degrees grab movement for screwing and unscrewing nuts and bolts". The pneumatic pipes would not allow the grab to spin though 360 degrees continuously without getting tangled. This, therefore, was not an option so I moved away from pneumatics.