specialist techniques to create a high-quality prototype

Question 1

What is wastage/addition?

Answer 1

• Cutting and removing material from stock forms, such as a sheet, is called wastage.
• Additive processes, like 3D printing, build up the desired shape from an additional source without waste.

Question 2

What is marking out?

Answer 2

• This is a process where the required shape is marked onto the stock material. There are many tools to help mark out accurately, including a try square, tape measure, or steel rule.

Question 3

What is drilling?

Answer 3

• Drilling is a process used when a hole is required in a material. Drilling can be done using a hand drill, or drill press/pillar drill.

Question 4

What is a pilot hole?

Answer 4

• a small diameter hole to guide a screw, preventing splitting

Question 5

What is a clearance hole?

Answer 5

• a hole large enough for a screw to fit through without the thread engaging.

Question 6

What is a countersunk hole?

Answer 6

• the top surface of the hole is flared to receive the screwhead flush.

Question 7

What is a counterbore hole?

Answer 7

• a flat-bottomed hole that enlarges another hole.

Question 8

What are some permanent metal joins?

Answer 8

• Joining metals can be done permanently using welding, brazing, epoxy resin adhesives and soldering.

Question 9

What are some temporary metal joins?

Answer 9

• Temporary methods include nuts and bolts, hinges, screws and rivets

Question 10

What is a lathe?

Answer 10

• A lathe is a machine that can be used to turn a piece of metal to create differently shaped round pieces.

Question 11

What is a milling machine?

Answer 11

• A milling machine is used to cult slots in blocks of metals, and to face off edges

Question 12

What are CAM machines?

Answer 12

• Computer aided manufacture
• CAM machines can be used to create features that allow parts to be joined to another part.
• The benefit of the CAM machine is that all cuts will be accurate and exact. Laser cutters can be used to cut materials like plastic sheets, and certain types or MDF
• CAM machines can also be used to engrave materials and mark out where holes, joins and other fixings may fit.

Question 13

What are temporary wood joins?

Answer 13

• Temporary methods include screws and nuts and bolts

Question 14

What are permanent wood joins?

Answer 14

• Permanent methods include wood joints and adhesives like PVA, epoxy resins and contact adhesives

Question 15

What are some box joints?

Answer 15

• Butt – a simple (but weak) join where the edges of the two pieces are glued together.
• Housing – one edge slots into a groove or slot cut in the other.
• Lap – a stronger joint where one piece fits into an L-shaped shoulder cut in the other.
• Dovetail – very strong and looks good. A flared ‘finger’ fits into the same shape removed from the other piece. This is complex to achieve.
• Finger joint - where straight lengths on one piece slot into gaps on the other piece.

Question 16

What are some frame joints?

Answer 16

• Dowel – a short length of round timber inserted into holes in both pieces to reinforce joints.
• Mortise and tenon – a very strong joint, a square ‘lug’ slots into a square channel and is glued.
• Mitre – two 45-degree angle cuts are made to form a 90-degree angle corner.
• Bridle – like a mortise and tenon joint but cut into the full width of the timber.

Question 17

How can polymers be joined?

Answer 17

• Plastics can be joined using nuts and bolts, screws, rivets and hinges.
• Adhesives can also bond polymers, and surfaces can also be ‘fused’ together using solvent cements.