Mechanism process

I have just completed my assignment questions as shown in my previous post. Now I am back in the workshop working on my 'Ocean motion' mechanism. It is finally starting to come together now as I have completed the box and some parts that go into it. Here is a picture of my mechanism so far

Questions for assessment 'Ocean Motion'

List the materials that were used in the construction of your mechanized toy.

·      Plywood

·      Hot glue gun

·      PVA glue

·      Circular Cams

·      Shaft

·      Crank

·      Dowel

·      Sand paper

Describe some environmental problems, which are caused by the overuse of wood products (i.e. deforestation).

The main environmental problem caused by the overuse of wood products is deforestation. Deforestation is the permanent destruction of indigenous forests and woodlands. The term does not include the removal of industrial forests such as plantations of gums or pines. Deforestation has resulted in the reduction of indigenous forests to four-fifths of their pre-agricultural area. Indigenous forests now cover 21% of the earth's land surface. Deforestation is brought about by, the conversion of forests and woodlands to agricultural land to feed growing numbers of people, the development of cash crops and cattle ranching, both of which earn money for tropical countries, commercial logging (which supplies the world market with woods such as meranti, teak, mahogany and ebony) destroys trees as well as opening up forests for agriculture, and falling of trees for firewood and building material; the heavy lopping of foliage for fodder; and heavy browsing of saplings by domestic animals like goats.

To compound the problem, the poor soils of the humid tropics do not support agriculture for long. Thus people are often forced to move on and clear more forests in order to maintain production.

Another environmental problem that is caused by the overuse of wood products is pollution. Pollution is the introduction of contaminants into the natural environment that causes adverse change. When a tree is chopped down to make paper, it goes through factories, which use up energy creating greenhouse gases, such as carbon dioxide. The waste from the factories then gets dumped into places such as the river creating pollution, which is very bad for the environment.

Explain the difference between ‘open-loop and closed-loop’ control systems. Give an example of each.

A closed-loop control system is a system in which the output has an effect on the input in such a way as to maintain the desired output value. An open-loop control system is a control system that does not have a feedback loop and is not self-correcting. An example of an open-looped control system would be a light switch. An example of a closed switch control system would be refrigerator temperature regulating system

Provide a brief description of 3 different types of mechanisms i.e. linkage, cams

Cam- A cam is a rotating or sliding piece in a mechanical usage used especially in transforming rotary motion into linear motion or vice-versa. It is often a part of a rotating wheel (e.g. an eccentric wheel) or shaft (e.g. a cylinder with an irregular shape) that strikes a lever at one or more points on its circular path.

       

Linkage-A mechanical linkage is an assembly of bodies connected to manage forces and movement. The movement of a body, or link, is studied using geometry so the link is considered to be rigid. The connections between links are modeled as providing ideal movement, pure rotation or sliding for example, and are called joints. A linkage modeled as a network of rigid links and ideal joints are called a kinematic chain.

       

Gear-A gear is a rotating machine part having cut teeth, or cogs, which mesh with another, toothed part in order to transmit torque. Two or more gears working in tandem are called a transmission and can produce a mechanical advantage through a gear ratio and thus may be considered a simple machine. Geared devices can change the speed, torque, and direction of a power source. The most common situation is for a gear to mesh with another gear, however a gear can also mesh a non-rotating toothed part, called a rack, thereby producing translation instead of rotation.

Provide an in depth description of the primary mechanism used in your toy

The primary mechanism used in my mechanical toy is the circular cams. In ‘ocean motion’ there are no cam followers but each individual wave piece acts as its own cam follower and is moving up and down in contact with the cam. ‘Ocean Motion’ works because when the crank is turned, it turns the shaft where the circular cams are attached. The circular cams rise at different times and heights creating the wave motion because the cams are slightly offset from the cam before it. This makes each wave piece lift up at different times.

Evaluate your finished product in terms of ergonomics, aesthetics and function.

Although my mechanism ‘ocean motion’ is not fully completed, I have a fair idea of how my finish mechanical toy will turn out. Ergonomics relates to the artefacts interaction with the human body such as things like comfort, safety, and convenience, ease-of-use and ease-of-sight. My quite proud of the mechanism that I have produced as it is very safe made with strong glue and extra plywood to make sure it doesn’t brake and injure someone who might be playing with it. The edges of ‘Ocean motion’ were also sanded down with sand paper to leave no sharp edges where a little child could potentially cut itself on it. ‘Ocean motion’ is very convenient not only for entertainment purposes but also for decoration purposes because its ease-of-sight is very good and it is a very interesting piece of work and looks attractive to the human eye. In terms of its ease-of-use, my mechanism is were fluent and is very easy to use although there are a few minor areas that need fixing.

Aesthetics relates to the mechanisms colour, shape, proportion, texture and any other visual aspect of the artefact. ‘Ocean Motion’ is very appealing to the human eye due its unusual shape and way of movement with the individual wave pieces moving up and down at different times which people would fine fascinating, and without building experience, one would be confused to how this motion is actually occurring. I find the proportion of my mechanism the perfect size for any space whether you’re using it as a decoration on a table or desk or whether it is just for entertaining purposes. It is a handy size that it is not too big and not too small. I don’t think I will have time to paint my mechanism due the shortage of lessons we had this term, but hopefully I can paint it when I take it home.

The function is the most important part to evaluating your product, because even though your product might look the part, it might not do its part. My mechanism ‘Ocean motion’ was designed to be able to turn a crank in a clockwise direction which will also rotate cams attached to a shaft that lift the individual wave pieces up and down at different times. My mechanism successfully does this although it is not perfect and is still a few areas that need improvement. However, ‘Ocean motion’ still performs very effectively creating a wave motion efficiently and fluently. If I were to do this assessment again I would have fewer boats on the waves and would turn the boat sideways so it looks like the boat is actually going up and down the wave. Ideally though, if we did get the option to do this again, I would probably choose a different me mechanism to make like the ‘Caterpillar’ and ‘Ocean motion’ is very time consuming and at times can be very difficult to make.