Wednesday, 24 April 2013

The Cube

Hello. Here are some photographs of things I have been doing recently, accompanied by a bit of text describing each photo

I have been experimenting with mechanisms which can raise a wooden cube, for my first donation box automata thing. A cube has to rise and rotate at the same time and then pause when it reaches the top and then come down again. I first tried a scissor lift design. It had potential but I couldn't work out how to get the cube on top to rotate at the same time.

My next idea was to have a block which the cube would sit in (via a brass rod).  I purchased Matthias Wandel's gear generator programme (highly recommended) and made a rack and gear to see about ways to raise and lower the block. Imagine this photo rotated 90 degrees clockwise and that the gear is lifting and lowering the piece of wood.

The start of my frame to test out the mechanism

I made a hole in the top to allow access for the cube. I tried to use Pythagoras'  theorem to calculate the size of the hole but I messed this up as I was thinking of the distance between 2 points in a square in 2d. I wasn't thinking about the largest distance between 2 points in 3d cube (silly me).

Gluing the cube

A cube

The cube mounted in it's block. The idea is to have a pin wheel gear sat horizontally underneath the cube and another pin wheel will be mounted to the side of the block with a pulley. The pulley will have a length of cord with a weight attached to it. As the block rises, the weight of the pulley will (hopefully) turn the pin wheels which will allow the cube to rotate. I have a feeling I have made this overly complicated. 

The block will have some tubes attached which will have guide rods inserted into, which will give the rising block a path to follow (up and down)

I settled for this design. The point in the middle of the block allows the rod to slide up and down. This allows it to move the block up and down. I tried it before as a fixed point on the block but it kept on wanting to move in an arc (like a compass).

Now I need to find a way to move it up and down and make it pause. I am thinking of a large wheel and a lock mechanism but will need to pro-type. I am also thinking about using pulleys but am not sure how to incorporate this. 

I am concerned that I am going about this in a really poor way. I'm not sure who reads this blog but if you have any ideas or think that I am going about this the wrong way, please let me know. I don't want to spend too long as I am making it in order to help raise money for an arts centre. The sooner it is completed, the better.