WEEK 6 Constructing Environments University of Melbourne
TIMBER WORKSHOP Materials: • • • • • • • •
3 planks of pine wood 1 sheet of plywood Nails Hammer Bench hook Saw Measuring tape Bevel
Activity: To construct a structure spanning 1m that is able to withstand pressure without destruction
The design of the structure: • The longest beams were the pine, therefore we decided to use the length of the pine to satisfy the criteria of the span required for the activity. • The two pieces of pine shown in the image on the right was used for that purpose • The final piece of pine was cut uniformly and used as bracing to hold the two pieces of pine together. • The bracing was fixed on to the timber using nails. Thin nails approximately 1inch in length was used. The head of the nail was flat and smooth.
1inch length was necessary for the nail, to ensure that it was securely fixed to the timber, while the flat headed nail was used to reduce the chances of the timber cracking when the nail is hammered and to minimize chances of the wood cracking when the load is applied to the structure. A difficulty that arose with nailing the bracing to the timber was that the bracing would move, which would make the structure unstable and shifty. â€˘
To overcome this issue the plywood sheet was used to pin down the bracing
This stopped the bracing from moving and made the structure more steady. Since structural performance depends on strength and stiffness (Ching,2010). The thinking behind the bracing was that it would increase the number of fixing which would thereby increase the stiffness of the structure.
HANDLING TOOLS AND EQUIPMENT AT THE WORKSHOP:
• When holding a saw while gripping the saw the second finger needs to point in the direction of the blade. This avoids sawing wood in a circular manner or a curve
• You need a comfortable stance when holding the saw. Your legs should be apart and your arm should move in a linear motion when sawing the timber. • A bench hook is used to keep the timber in place which makes sawing easier, it also acts as a preventive measure to avoid harming the tables
• Before beginning to saw. The point you wish to cut needs to be marked on the timber on both the top and side surfaces. • Afterwards you need to run the saw lightly along the marked edge until it forms a crevice. • Once this is done the sawing process becomes easier and only requires the pushing and pulling of the saw to cut the timber into 2 sections
• The nail needs to be placed accurately before using the hammer • Hammering is more effective when using two or 3 strong blows to hammer the nails in rather than using many gentle blows to fix the pieces of timber together with the nails • Its best not to hammer in nails near the edges of the timber, as it is more likely to crack in those locations when under pressure H a m m e r
• The choice of nail too impacts the final structure created. When using nails on timber its best to use the flat ended nails as they will not pierce through the wood and destroy the wood from within. • When removing nails, the back of the hammer is used to securely clutch the nail by its head. When the hammer is pulled along the length of the wood the nail will be removed. This uses less effort in removing the nail, whereas in the image to the right the right the hammer is not being pulled along the Length of the wood which makes that method of removing nails inefficient and time consuming
EXPOSING THE STRUCTURES TO A LOAD • The load used on the structure was a point load. When designing the structure we were unaware that the load used on the structure will be a point load, therefore we deigned our structure to resist uniform loads • The structure shown in the image on the left was the most successful of the structures in resisting the loads. It withstood upto 380kgs.