Shaping
Wood, Metal and Plastic can be shaped using various methods and within these processes there are many common misconceptions and basic principles for students to comprehend.
Common principles of shaping material in school:
Common misconceptions with shaping in school:
When it comes down to shaping any material in schools students generally believe that the best and the only process is to cut the materials using tools such as a hacksaw. As a result of this some work is finished to a poor standard, some material can be damaged within the production and possible injury can occur as a result and in addition the students are not learning the other process- which could be more appropriate for the desired manipulation method. In reflection this it in turn leads to lack of understanding and lack of skill with the subject area.
- Prepare the materials appropriately
- Insure that the correct tools are used within the desired process
- Check that all tools are suitable to use and are conforming to the Health and Safety guides
- Bare in mind the basic principles of using tools within the shaping process, E.G Hold the tool by the handle.
Common misconceptions with shaping in school:
When it comes down to shaping any material in schools students generally believe that the best and the only process is to cut the materials using tools such as a hacksaw. As a result of this some work is finished to a poor standard, some material can be damaged within the production and possible injury can occur as a result and in addition the students are not learning the other process- which could be more appropriate for the desired manipulation method. In reflection this it in turn leads to lack of understanding and lack of skill with the subject area.
Shaping by WASTING
Shaping by wasting is a process that can be used for any type of material in this case - Wood, Plastic and Metal. The definition of this process "To cut away at a piece of material to leave the desired shape"
The main common principles within this process of shaping material by wasting is that all tools need to be used in the best and appropriate way baring in mind the basic principles, E.G Cutting a piece of wood along the grain with the correct saw and body positions. Health and Safety also needs to be put into consideration for example, Keeping the piece of material in the appropriate holding tool IE, and Bench or Engineer vice.
The common misconceptions are that not every tool within the workshop can be used on every material. Using the incorrect tool on a piece of material can lead to work being damaged or lead to serious injury if for example if a Chisel or file does not have a handle - the tang could cause serious damage. Many students think that the bigger the tool the better the performance, just because a tool is big it is not to say that it will cut better or faster for that matter.
A prime and common principle that can be applied to avoid this common misconceptionis to pay more attention to the tool. We have been informed that with a saw you can identify it's ability to cut before actually using it on a material. This would be indicated through the teeth per inch (TPI). The higher the TPI on a saw the more material will be removed when sawing. Lower TPI would be used for starter cuts and this can often cause confusion with students which in turn means that a higher TPI could be used for a starter cut and the results are that too much materials has been removed. The same mistake can be made when using the incorrect TPI on a certain material; students often use lower TIP's saws on metal when metal as a material needs much more TPI as it is a harder material, this common principle can be remembered as Lower TPI for most wood, and Higher TPI for metal. The same principle of TPI can apply and be transferred when shaping by wasting if using machinery- Higher TPI blades would used for cutting Metal & Plastic.
Personal experience with this example- When I was experimenting with machines and materials I used a finer blade on the scroll saw to cut some acrylic and as a result it cracked.
Files work in a very similar way to saws, instead of TPI, files consider the GRADE. The grade like TPI can determine how much material is removed and you can always identify this by looking at the tool before using it. Bhav has told us that a bastard file is used when you need to remove a lot of material, the grade is courser. Finer blades will take smaller amounts of material away.
Personal experience with this - In Design and Make we explored modelling techniques and I used styrofoam to create a model. I used a much courser rasp and as a result the material filed away much quicker and this was not what I intended for it to do because the piece of foam I was using was small and I wanted it to be filed evenly with accuracy.
To conclude.... Although as a misconception not every tool is appropriate within this process the most important and common principle within schools also regarding this matter is that some hand and machine tools can in fact be used with two types of materials.This occurs more frequently with Metals & Plastics for example.
Common principles with shaping by wasting using hand tools and machines:
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Example of me shaping a piece of acrylic with my two part mould