.
1: The weld is made by a combination of heat, pressure and time.
2: The resistance of the material to be welded to current flow, causes a localised heating.
3: The pressure is exerted by the tongs and tips.
4: The time is how long current flows in the joint. This is determined by the material thickness and the material type.
How does it work?
1: Resistance spot welding happens when current flows through the tips and the pieces of metal being joined.
2: The resistance of the metal to the electrical current flow, causes localised heta in the joint and creates a weld.
3: The weld is being made inside the workpieces.
Safety Hazards:
1: Flying sparks can cause fire and explosion.
2: Flying sparks and hot metal are thrown off from the weld and can burn or injure eyes and skin.
3: Electric shock can happen from the wiring.
4: Fumes from metals coated with cleaner, paints and plating can be dangerous.
Avoiding Hazards:
1: Wear Safety goggles or face shield.
2: Wear long sleeves.
3: Do not weld near flammables.
4: Fire extinguisher should be located nearby.
5: Wear dry insulating gloves.
6: Do not put hands between the tips.
7: Do not breathe the fumes, use proper ventilation.
8: Read materials safety data before use.
9: Do not touch hot work piece or tips with bare hands.
10: Let tips cool down before handling.
Vacuum Forming:
1: A technique used in batch production or mass production.
2: A process that enables thermoplastics to be formed into complicated shapes such as product packaging or car dashboards.
How does it work?
1: A sheet of plastic is heated until the plastic becomes soft and flexible.
2: The air is then sucked out from underneath the plastic using a vacuum pump.
3: Atmospheric pressure presses down on top of the plastic sheet which in turns presses down onto the mould.
4: The plastic sheet takes the shape of the mould.
What materials can be used?
1: Thermoplastics, the most common being HIPS or high impact polystyrene sheeting.
What materials can I use for the mould?
1: Wood ( plywood, hardwoods, MDF).
2: Structural foam.
3: Machined or cast aluminium.
4: Hardened clay.
5:Steel.
6: Lead.
Stages of making the mould:
1: The sides of the mould must slope slightly to allow the removal of the plastic shape after vacuum forming.
2: The mould must be sanded, polished or smoothed depending on the material used.
3: Drill small holes in the mould to allow the air to be easily sucked through the vacuum pump.
4: The holes prevent small air pockets from being trapped when the sheet forms.
5: The mould must not be too deep in order for the excess not to stick at the corners.
Stage of the vacuum forming:
1: Place the mould on the platen which should be in the lowered position.
2: Clamp plastic sheet to the top of box using toggles clamps.
3: Bring heating unit on top of plastic sheet.
4: Heat plastic until it turns soft. Test softness with a blunt tool, it should feel rubbery.
5: Raise the platen towards the plastic.
6: Suck the air out by switching on the vacuum pump. The plastic will press down over the mould.
7: The sheet is unclamped from the frame and the mould is removed.
8: Excess material around the moulding is trimmed off.
Safe system of work:
1: Use local ventilation hood on top of the vacuum former when in use.
2: Avoid touching hot plastic.
Guillotine/ Shears:
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A guillotine is a machine used to accurately cut sheet metal. It may be foot-operated, hand operated or powered.
It is designed to cut flat stock with a minimum of bending. The foot-operated guillotine can cut mild steel up to 1.6mm while non ferrous metals can be cut up to 2,4mm.
Wire should not be cut on a guillotine as it will damage the blade.
The hand-operated guillotine has a hole located in the upper part of the top blade designed to fit wire and cut it.
How does it work?
An angled blade is driven down which slices the metal along the length of the cut, shearing off very clearly the material.
Safety Hazards:
1: Sharp edges on cut materials can cause cuts.
2: lack of space around the guillotine can lead to the operators being pushed by passers by.
3: Manual handling of sheet material must be considered carefully.
Risks:
1: the operator can sustain seriuos injuries such as crushed or amputated fingers if contact is made with the blade.
2: Strain injury can occur while handling large and awkward sheets of metal.
3: Foot injuries: if two operators work on a guillotine, one holding the metal , the other activating the foot pedal, make sure the person holding the metal has his or her foot safely away from underneath the pedal.
Avoiding hazards:
1: The guard on the front of the guillotine is protecting the blades from being exposed and therefore protecting hands.
2:The wire cage at the back of the guillotine prevents the operator from supporting the work to be cut from the rear of the machine and therefore prevents hand injuries.
3: The guillotine is located so sufficient space is available for sfae handling of the material.
4: Gloves should be worn when handling cut materials.
5: Only cut materilas within the capacity of the machine should be used.
6: Use additional support when cutting long material which cannot be adquately supported.
7: In the hand-operated guillotine, the hole located in the upper part of the top of the blade, is used to locate the saftey pin preventing the handle from falling on the operator.
Sandblasting /Bead blasting:
How does it works?
The process of smoothing, shaping and cleaning a hard surface by forcing solid particles across that surface at high speed usually with compressed air. The work is located inside the snadblasting unit which is now securely closed.
The process of smoothing, shaping and cleaning a hard surface by forcing solid particles across that surface at high speed usually with compressed air. The work is located inside the snadblasting unit which is now securely closed.
The operator's hands are fed through flaps located at the front of the machine.
Indside the blasting unit a gun is directed towards the work and operated by pressing the pedal on the right front of the machine.
This activates the release of the abrasive, sand for sandblaster or glass beads as used in a bead blaster.
What is it used for?
1: Cleaning sand and irregularities from foundry castings.
2: Cleaning and removing paint from metal surface.
3: Etching or frosting glass.
4: Cutting through glass.
5: Forming a pattern first having concealed some area of the material with tape and sandblasting the exposed remaining areas.
Safety Hazards:
1: Silicolosis: due to the airborne concentration of crystalline silica.
2: Finely fractured particles of material being removed such as lead paint for example.
Avoiding Hazards:
1: The abrasive sand should have less than 1% crystalline silica.
2: Use respiratory protection or face mask.
3: Switch extraction on. It will prevent any leakage of dust to the outside.
4: Wash hands and face before eating, drinking or smoking.
5: Wear protective clothing.
Hot Wire Strip Heater:
How does it work?
A sheet of thermoplastic material (e.g.acrylica, ABS, polycarbonate) is heated in a strip along its length.
How does it work?
A sheet of thermoplastic material (e.g.acrylica, ABS, polycarbonate) is heated in a strip along its length.
The width of the heated area is normally around twice the thickness of the material.
Due to the characteristics of the material, it becomes flexible when heated, allowing it to bent to the required shape. Once cooled the bent material retains the formed shape.
1: The position of the fold is marked with a china-graph pencil. Allowing the line to be easily removed later.
2: The plastic sheet is placed above the heating element.
3: The strip heater is truned on and the plastic is truned over every 30 seconds to 1 minute. This stops the heat rising element damaging the surface of the plastci.
4: When the plastic becomes flexible it can be placed in a jig. The jig is made to the correct angle chosen by the operator. A block of wood is then pressed against the plastic to hold in position as it cools.
Safety Hazards:
1: Burns from hot material and hot wire.
2: Respiratory problems due to the fumes being released when plastics heated.
Avoiding Hazards:
1: Only use sheet perspex, acrylic or polystyrene sheets.
2: Ensure machine is connected to the correct power supply.
3: Ensure material support bars are inplace.
4: Ensure machine is clear of all other materilas.
5: Understand the use of the on and off switch and simmer stat control.
6: Always wear gloves.
7: Keep hands away from the heater element.
8: Protective film must be removed from the material before application to the heat source.
9: Machine to be used in a ventilated area.
Hot Wire Foam Cutter:
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A hot wire foam cutter is used to cut polystyrene foam and similar materials. It is used to make signage, architectural solid modeling props, prototyping, aircraft designs, surfboard construction.
How does it work?
1: A thin metal wire often made of nichrome or stainless steel or a thicker wire preformed into a desired shape is heated via electrical resistance to approximately 200 degrees C.
2: As the wire is passed through the material to be cut, the heat from the wire vaporises the material just before it would have made contact with it, creating a smooth cut.
3: The depth of the cut is limited only by the iwre length. The width of the cut is limited by the throat.
4: A template can be placed on each side of a foam block to guide a taut hot wire to form a tapered or prismatic shape.
Foams suitable for hot wire cutting:
All thermofusible expanded foams are suitable. Thes are materials that melt at a relatively low temperature.
1: Expanded polystyrene ( blocks of expanded white foams).
2: Extrudud polystyrene ( blue, grey, pink smooth plates)
3: Plexiglass.
4: Flexible expanded polypropylene foams, ideal for shock protecting.
Safety Hazards:
1: Burns due to contact with hot wire.
2: Respiratory danger due to the fumes generated by the material being cut.
Avoiding Hazards:
1: Use a face mask.
2: Ensure ignition light operates when power is on.
3: Do not touch wire when machine is switched on.
4: Allow adequate ventilation.
5: Ensure cutting wire is not broken.
6: Ensure machine table is clear od all off cuts or other obstructions.
Laser Cutting:
Laser cutting is a technology that uses a laser to cut materials. It is used in industrial manufacturing.
How does it work?
Laser cutting works by directing the output of a high power laser by computer ata material to be cut. The materials either melts, burns or vaporises away leaving an edge with a high quality surface finish.
What material can I cut?
Industrial laser cutters are used to cut flat sheet material as well as structural and piping materials. Some laser cutters can perform cutting operations on parts that have been pre-formed by casting or machining.
How does it work?
Laser cutting works by directing the output of a high power laser by computer ata material to be cut. The materials either melts, burns or vaporises away leaving an edge with a high quality surface finish.
What material can I cut?
Industrial laser cutters are used to cut flat sheet material as well as structural and piping materials. Some laser cutters can perform cutting operations on parts that have been pre-formed by casting or machining.
Our 30 Watt laser cutter can cut or engrave the following materials:
1: Paper.
2: Fabric.
3: Foam.
4: Polystyrene.
5: Perspex.
6: Acrylic.
7: Plywood.
8: Polycarbonate plastic.
9: Vinyl.
10: Leather.
11: MDF.
12: Balsa Wood.
13: Rubber.
14: Card
15: Hardwoods .(more for engraving, difficult to cut).
Advantages of laser cutting over mechanical cutting:
1: Precision: the laser does not wear out. There is also a reduced chance of warping the material that is being cut as laser systems have a small heat affected zone.
Safety Hazards:
1: Fire,
2: Burns.
3: Respiratory damage due to the fumes generated by the cutting process.
4: Eye damage.
Avoiding Hazards:
1: Switch fumes extraction system on before commencing any cutting.
2: Ensure that any fumes are exhausted in accordance with health and safety requirements.
3: Do not obstruct air vents.
4: Avoid eye or skin exposure to direct or scattered radiation.( the laser emits invisible radiation).
5: Safety lid must be shut before commencing cutting.
6: When safety lid is lifted, avoid head contact with the raised cover.
7: Do not leave the laser cutter unattended at any time while operating the machine.
Creating files for the FB serie laser cutter:
1: DXF' s from illustrator become one continuous path and cannot be individually selected. therefore DXF are not good files to use.
2: DWG' s from illustrator preserve individual lines if drawn as such. Good files to use.
3: DWG' s from illustrator preserve continuous paths/objects if drawn as such. Anything to be engraved needs to be drawn like this , facilitating the generation of scan line in the FB series laser cutter's Aps-Ethos computer program. DWG are good files to use for this purpose.
4: DXF's from autocad become one continuous path and cannot be individually selected. Not good for this purpose.
5: DWG' s from autocad preserve individual lines if drawn as such, however continuous path/object disappear. Not good files to use if one wants to engrave.
6: .AI' s downsaved to illustrator 8 are good as both objects and single lines are preserved allowing for easy engraving.
7: DWG' s from autocad can be opened inillustrator and resaved as a new DWG preserving both objects and lines.
8: If one brings an Illustrator .AI file into Aps-Ethos, it preserves the work area which can cause layout problems when cutting.
A DWG does not preserve the work area.
Conclusion: DWG' s saved as Cad 2000/LT from illustrator are best as objects and lines are preserved with the work area being discarded.
Creating files for the FB serie laser cutter:
1: DXF' s from illustrator become one continuous path and cannot be individually selected. therefore DXF are not good files to use.
2: DWG' s from illustrator preserve individual lines if drawn as such. Good files to use.
3: DWG' s from illustrator preserve continuous paths/objects if drawn as such. Anything to be engraved needs to be drawn like this , facilitating the generation of scan line in the FB series laser cutter's Aps-Ethos computer program. DWG are good files to use for this purpose.
4: DXF's from autocad become one continuous path and cannot be individually selected. Not good for this purpose.
5: DWG' s from autocad preserve individual lines if drawn as such, however continuous path/object disappear. Not good files to use if one wants to engrave.
6: .AI' s downsaved to illustrator 8 are good as both objects and single lines are preserved allowing for easy engraving.
7: DWG' s from autocad can be opened inillustrator and resaved as a new DWG preserving both objects and lines.
8: If one brings an Illustrator .AI file into Aps-Ethos, it preserves the work area which can cause layout problems when cutting.
A DWG does not preserve the work area.
Conclusion: DWG' s saved as Cad 2000/LT from illustrator are best as objects and lines are preserved with the work area being discarded.
Scroll Saw:
A scroll saw is a small electric or pedal operated saw useful for cutting intricate curves where a jigsaw or coping saw is not appropriate.
A scroll saw is a small electric or pedal operated saw useful for cutting intricate curves where a jigsaw or coping saw is not appropriate.
It is somewhat similar to a band saw, but unlike band saw where the sawblade is a continuous loop, scroll saws use sawblades similar to those used by coping saws and operates through a reciprocating up and down motion.
What materials can I cut?
1: Wood.
2: Card.
3: Plastic.
4: Metal.
Safety Hazards:
1: Cuts on hands,
2: Eye damage.
Avoiding Hazards:
1: Always wera protective goggles.
2: Ensure guard is correctly placed.
3: Ensure blade is set at the correct tension and facing the right way.
4: Ensure blade is correctly set to run freely through the guides.
5: Ensure appropriate blade is being used for the material to be cut.
6: Ensure saw table is firm and clear of offcuts or other obstructions.
7: Never present hands to the blade.
8: Before changing blade, ensure power is turned off.
9: Ensure that the material contains no foreign bodies such as nails.
10: Ensure that the material is of correct type and size.
Bandsaw:
A bandsaw is a saw that can be used for wood working,metalworking and a variety of other materials.
It gets its name from its blade consisting of a narrow band of toothed metal. This band rides on two wheels inthe same vertical plane with a space between them. Bandsaws are useful for cutting irregular shapes. The radius of a curve that can be cut is determined by the width of the band.
What materials does it cut?
1: Wood.
2: Metal.
3: Perspex.
4: Plastics.
Safety Hazards:
1: Eye Injury.
2: Hand injury.
3: Ear damage.
4: Respiratory hazard due to dust.
How to avoid hazards:
1: Wear safety goggles or face shield.
2: Wear hearing protection suitable for the level and frequency of the noise you are exposed to.
3: Switch extraction on.
4: Make sure all guards are in place and properly adjusted and all band wheels are enclosed.
5: Adjust blade guard height to about 3mm or 1/8 inch above the material being cut.
6: Ensure the blade is tracking correctly and runs freely in and against the upper and lower guide rollers.
7: Ensure the blade is under proper tension.
8: Use band saw blades that are sharp, properly set and suitable for the job.
9: Hold stock firmly and flat on the table tp prevent stock from turning and drawing your fingers against the table.
10: Use a push stick when removing cut pieces from between the saw blade or when hands are close to the blade.
11: Keep your hands either side of the blade, not in line with the cutting line and the blade.
12: Do not use execessive force when pushing the wood against the blade.
13: Do not back the stock away from the blade while the saw is in motion if the work piece binds or pinches on the blade.
14: Do not stop a band saw by thrusting stock against the cutting edge on the side of the blade immediately after the power has been stopped.
15: Do not remove sawdust or cuttings from the table by hand. Use a stick or brush.
16: Do not leave the bandsaw unattebded. Turn off the power and make sure the machine has stopped running before leaving the area.
Belt Sander:
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A belt sander is a machine used to quickly sand down wood and other materials such as plastic and card for finishing purposes.
How does it work?
It consists of an electrical motor that turns a pair of drums on which seamless loop of sandpaper is mounted. A belt sander can be either hand held where the sander is moved over the material, or fixed where the materila is moved to the sanding belt.
Belt sanders have a very aggressive action on wood and are normally used for the beginning stages of the sanding process to remove rapidly material.
Fitted with fine grit sand paper, it can be used to assure a completely smooth surface.
Fixed belt sanders are used to remove no ferrous metals such as aluminium. These metals clog quickly grinding wheels while belt sanders continue to grind without clogging.
Woodworking Sanders include:
1: Oscillating spindle sander or bobbin sandert.
2: Random orbital sander.
3: Drum sander.
4: Strke sander.
5: Belt sander.
6: Disc sander.
Safety Hazards:
1: Hand injury.
2: Respiratory damage.
3: Ear damage.
Avoiding Hazards:
1: Ensure sanding disc is firmly attached to rotating panel.
2: Ensure suitable disc is being used for material being snaded.
3: Ensure quarter guard is securely in place.
4: Ensure sanding table is firm and clear of offcuts and other obstructions.
5: Ensure dust extraction equipment is operating effectively.
6: Always wera protective goggles.
7: Long hair is to be tied back.
8: Hands must never go near the sanding disc.
9: No loose items of clothing should be worn while sanding.
10: Floor area should be clear of offcuts or debris.
DRILL:
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A drill is a tool with a rotating drill bit used for drilling holes in various materials such as metals, wood, plastics, etc.
How does it works?
The drill bit is gripped by a chuck at one end of the drill and is pressed down by manipulating the handle against the material and rotated. The tip of the drill does the work of cutting into the target material, slicing off thin shavings or grinding off small particles.
Different types of drills:
1: Hammer drill (for drilling masonary).
2:Rotary hammer drill (for drilling masonary).
3: Cordless drill (electric drill using batteries).
4: Drill press or pillar drill (for accurate holes).
5: Geared head drill (similar to drill press).
6: Mill drill (light alternative to a milling machine).
7: Pendant drill (similar to a dentist drill, it is used in jewellery making).
8: Bow drill ( mechanical drill known as the oldest drill).
9: Micro drill ( drill holes less than 0.5mm).
Safety Hazards:
1: Eye or face injury.
2: Hand injury.
Avoiding Hazards:
1: Ensure drill bit is securely fixed into drill chuck.
2: Ensure drill bit is the correct type for the material to be drilled.
3: Ensure working area is cleared of all offcuts and obstructions.
4: Understand the use of the on/off switch and emergency stop.
5: Ensure the material to be drilled is free from foreign bodies such as nails.
6: Ensure that the material is adequately supported.
7: Do not wear gloves when drilling.
8: Wear goggles.
9: Ensure operator has hair tied back.
10: Ensure operator has no loose clothing or jewellery ( this may get caught into the drill).
Drill Bit:
Drill bits are cutting tools used to create cylindrical holes.
Bits are held in a tool called a drill which rotates them and provides axial force to create a hole.
Specialised bits are also available for non cylindrical holes.
Metal Drills:Twist drill: It is a bit used to create holes in metal, plastic and wood. It is produced in diameters covering a range from 0,05mm to 100mm.
Lengths up to about 1000mm are available for use in powered hand tools.
Centre drill and Spotting Drill:
Spotting drill bits are used in metalworking to provide a starting hole for a larger sized drill bit. This hole is called a pilot hole. Centre drill bits are used to make a conical indentation in the end of a work piece in which to mount a lathe centre.
Core Drill:
A core drill bit is used to enlarge an existing hole. It has no starting point or means of starting a hole.
Wood Drills:
Lip and Spur Drill:
The lip and spur drill bit is a variation of the twist drill which is optimised for drilling in wood. It is also called the brad point bit or dowelling bit.
The lip and spur drill bit has the outside corner of the cutting edges leading so that it cuts the periphery of the hole before the inner parts of the cutting edges plane off the base of the hole.
Lip and spur drills are effective in soft plastics.
Spade Drill:
Spade drill bits are used for rough boring in wood. They tend to cause splintering when they emerge from the work piece.
They are flat with a centering point and two cutters. The cutters are often equipped with spurs in an attempt to ensure a cleaner hole. Intended for high speed use, they are used with electric hand drills.
Forstner Bit:
Forstner bits bore precise, flat bottomed holes in wood in any orientation with respect to the wood grain.
They can cut on the edge of a block of wood or cut overlapping holes.
Because of the flat bottom to the hole, they are useful for drilling through veneer already glued to add an inlay.
They need to be used in a drill press since they require great force to push them into the material.
Bits are available in sizes from 8mm to 50mm. Sawtooth bits are available uo to 100mm.
Centre Bits:
The centre bit is optimised for drilling in wood with a hand brace. It is a tapered screw head that screws into the wood as the drill is turned. There is no need for any force to push the bit into the work piece. This drill is ideal for a hand tool.
Auger Bit:Auger bit cut in the same way as the centre bit described above. The auger adds a long deep spuiral flute for effective chip removal. Its diameter ranges from 6mm to 30mm, but auger up to 600mm long are available. Modern design of auger with a single spur, a single radial cutting edge and a single flute are used in protable power tools.
Other Materials:
Masonry Drill:
It is a variation of the twist drill bit with an insert of tungsten carbide braxzed into the steel to provide the cutting edges.
Masonry bits are used witha hammer drill. The bit is both rotated and hammered into the work piece. It is available in diameters from 5mm to 40mm.
Masonry bits up tp 1000mm long can be used with hand potable power tools.
Hole Saw:
Hole saw can be used on wood, metal and other materials.
It is a saw that is in the shape of a circle and is used in a drill to cut large holes in reasonably thin material.
The hole saw uses the cutting effect of saw teeth.
PCB through holes Drill:
Printed circuit board are made of fibreglass which due to being highly abrasive, would quickly ruin a normal drill bit. Carbide PCB bits outlast high speed bits. It is made of solid tungsten carbide.
PCB bits are mounted in a collet rather than a chuck. It cannot be used in a hand drill due to its delicate nature and the britleness of its material. It needs to be used in a drill press on a high speed.
Dill Bits for Glass and Ceramic Structures:
A drill bit suitable for making holes in glass and ceramic structures has an elongated member with a cutting end and a retaining end with an axis passing through its end.
The portion of the member near the retaining end is formed as a shank which is capable of being suitably held and rotated by a chuck.
How does it works?
The drill bit is gripped by a chuck at one end of the drill and is pressed down by manipulating the handle against the material and rotated. The tip of the drill does the work of cutting into the target material, slicing off thin shavings or grinding off small particles.
Different types of drills:
1: Hammer drill (for drilling masonary).
2:Rotary hammer drill (for drilling masonary).
3: Cordless drill (electric drill using batteries).
4: Drill press or pillar drill (for accurate holes).
5: Geared head drill (similar to drill press).
6: Mill drill (light alternative to a milling machine).
7: Pendant drill (similar to a dentist drill, it is used in jewellery making).
8: Bow drill ( mechanical drill known as the oldest drill).
9: Micro drill ( drill holes less than 0.5mm).
Safety Hazards:
1: Eye or face injury.
2: Hand injury.
Avoiding Hazards:
1: Ensure drill bit is securely fixed into drill chuck.
2: Ensure drill bit is the correct type for the material to be drilled.
3: Ensure working area is cleared of all offcuts and obstructions.
4: Understand the use of the on/off switch and emergency stop.
5: Ensure the material to be drilled is free from foreign bodies such as nails.
6: Ensure that the material is adequately supported.
7: Do not wear gloves when drilling.
8: Wear goggles.
9: Ensure operator has hair tied back.
10: Ensure operator has no loose clothing or jewellery ( this may get caught into the drill).
Drill Bit:
Drill bits are cutting tools used to create cylindrical holes.
Bits are held in a tool called a drill which rotates them and provides axial force to create a hole.
Specialised bits are also available for non cylindrical holes.
Metal Drills:Twist drill: It is a bit used to create holes in metal, plastic and wood. It is produced in diameters covering a range from 0,05mm to 100mm.
Lengths up to about 1000mm are available for use in powered hand tools.
Centre drill and Spotting Drill:
Spotting drill bits are used in metalworking to provide a starting hole for a larger sized drill bit. This hole is called a pilot hole. Centre drill bits are used to make a conical indentation in the end of a work piece in which to mount a lathe centre.
Core Drill:
A core drill bit is used to enlarge an existing hole. It has no starting point or means of starting a hole.
Wood Drills:
Lip and Spur Drill:
The lip and spur drill bit is a variation of the twist drill which is optimised for drilling in wood. It is also called the brad point bit or dowelling bit.
The lip and spur drill bit has the outside corner of the cutting edges leading so that it cuts the periphery of the hole before the inner parts of the cutting edges plane off the base of the hole.
Lip and spur drills are effective in soft plastics.
Spade Drill:
Spade drill bits are used for rough boring in wood. They tend to cause splintering when they emerge from the work piece.
They are flat with a centering point and two cutters. The cutters are often equipped with spurs in an attempt to ensure a cleaner hole. Intended for high speed use, they are used with electric hand drills.
Forstner Bit:
Forstner bits bore precise, flat bottomed holes in wood in any orientation with respect to the wood grain.
They can cut on the edge of a block of wood or cut overlapping holes.
Because of the flat bottom to the hole, they are useful for drilling through veneer already glued to add an inlay.
They need to be used in a drill press since they require great force to push them into the material.
Bits are available in sizes from 8mm to 50mm. Sawtooth bits are available uo to 100mm.
Centre Bits:
The centre bit is optimised for drilling in wood with a hand brace. It is a tapered screw head that screws into the wood as the drill is turned. There is no need for any force to push the bit into the work piece. This drill is ideal for a hand tool.
Auger Bit:Auger bit cut in the same way as the centre bit described above. The auger adds a long deep spuiral flute for effective chip removal. Its diameter ranges from 6mm to 30mm, but auger up to 600mm long are available. Modern design of auger with a single spur, a single radial cutting edge and a single flute are used in protable power tools.
Other Materials:
Masonry Drill:
It is a variation of the twist drill bit with an insert of tungsten carbide braxzed into the steel to provide the cutting edges.
Masonry bits are used witha hammer drill. The bit is both rotated and hammered into the work piece. It is available in diameters from 5mm to 40mm.
Masonry bits up tp 1000mm long can be used with hand potable power tools.
Hole Saw:
Hole saw can be used on wood, metal and other materials.
It is a saw that is in the shape of a circle and is used in a drill to cut large holes in reasonably thin material.
The hole saw uses the cutting effect of saw teeth.
PCB through holes Drill:
Printed circuit board are made of fibreglass which due to being highly abrasive, would quickly ruin a normal drill bit. Carbide PCB bits outlast high speed bits. It is made of solid tungsten carbide.
PCB bits are mounted in a collet rather than a chuck. It cannot be used in a hand drill due to its delicate nature and the britleness of its material. It needs to be used in a drill press on a high speed.
Dill Bits for Glass and Ceramic Structures:
A drill bit suitable for making holes in glass and ceramic structures has an elongated member with a cutting end and a retaining end with an axis passing through its end.
The portion of the member near the retaining end is formed as a shank which is capable of being suitably held and rotated by a chuck.
Plasma Cutter:
A plasma cutter is a machine that is used to cut steel and other metals or sometimes other materials using a plasma torch.
How does it work?
In the process an inert gas and compressed air is blown at high speed out a nozzle: at the same time an electrical arc is formed through that gas from the nozzle to the surface being cut, turning some of that gas into plasma.
The plasma is hot enough to melt the metal being cut and moves sufficiently fast to blow molten metal away from the cut.
Plasma is an effective means of cutting thin and thick materials alike. Hand held torches can cut up to 25mm thick plate while computer controlled torches can cut steel up to 300mm thick.
Since plasma cutters produce a very hot and localised cone to cut with, they are extremely useful for cutting sheet metal in curved or angled shapes.
The circuit must be earthed, this is done by connecting a work cable to the table where the cutting is done.
Safety Hazards
1: Respiratory fumes).
2: Noise.
3: Ultraviolet radiation.
4: Gases.
5: Electric shock.
6: Explosion from cutting.
7: Burns.
Avoiding Hazards:
1: Switch on ventilation system (most fumes are emitted below the plate being cut, local exhaust ventilation (LEV) is necessary.
2: Wear ear defenders,
3: Wear protective equipment such as industrial gloves, long sleeves and welding mask.
4: Safe system of work.
5: Keep your head out of the fumes when cutting.
6: Use safety glasses and a shield with the proper filter and cover plates to protect your eyes from sparks and the rays from the arc.
7: Ensure nearby personel is protected from watching the arc and hot spatter of metal.
8: Vent hollow castings or containers before cutting because of the risk of explosion.
9: Keep your body away from nozzle and plasma arc.
10: Connect the work cable to the work piece as close a s possible to the are being cut.
11: Do not place your body between the torch and the work cables.
12: Keep flammable material away.
How does it work?
In the process an inert gas and compressed air is blown at high speed out a nozzle: at the same time an electrical arc is formed through that gas from the nozzle to the surface being cut, turning some of that gas into plasma.
The plasma is hot enough to melt the metal being cut and moves sufficiently fast to blow molten metal away from the cut.
Plasma is an effective means of cutting thin and thick materials alike. Hand held torches can cut up to 25mm thick plate while computer controlled torches can cut steel up to 300mm thick.
Since plasma cutters produce a very hot and localised cone to cut with, they are extremely useful for cutting sheet metal in curved or angled shapes.
The circuit must be earthed, this is done by connecting a work cable to the table where the cutting is done.
Safety Hazards
1: Respiratory fumes).
2: Noise.
3: Ultraviolet radiation.
4: Gases.
5: Electric shock.
6: Explosion from cutting.
7: Burns.
Avoiding Hazards:
1: Switch on ventilation system (most fumes are emitted below the plate being cut, local exhaust ventilation (LEV) is necessary.
2: Wear ear defenders,
3: Wear protective equipment such as industrial gloves, long sleeves and welding mask.
4: Safe system of work.
5: Keep your head out of the fumes when cutting.
6: Use safety glasses and a shield with the proper filter and cover plates to protect your eyes from sparks and the rays from the arc.
7: Ensure nearby personel is protected from watching the arc and hot spatter of metal.
8: Vent hollow castings or containers before cutting because of the risk of explosion.
9: Keep your body away from nozzle and plasma arc.
10: Connect the work cable to the work piece as close a s possible to the are being cut.
11: Do not place your body between the torch and the work cables.
12: Keep flammable material away.
Tube and Pipe Bender:
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Rotary Draw Benders;
Rotary benders are precise in that they bend using tooling or dies sets which have a constant centre line radius. The die set consists of two parts: The former die creates the shape to which the material will be bent. The counter die does the work of pushing the material into the former die while traveling the length of the bend.
Handrails, frames, roll cages, handles and more are typical for rotary draw benders.
Roll Bender:
Roll benders use three rolls to bend solid, extrusions, tube and pipe to various diameters by adjusting one or two rolls. The pyramid style roll benders have one moving roll, usually the top roll.
Large arcs, circles and spirals are typical for roll benders.
Safety Hazards:
Hand injury.
Avoiding Hazards:
While using the roll bender ensure fingers are located away from the roller as they are being activated by the operator.
Rotary benders are precise in that they bend using tooling or dies sets which have a constant centre line radius. The die set consists of two parts: The former die creates the shape to which the material will be bent. The counter die does the work of pushing the material into the former die while traveling the length of the bend.
Handrails, frames, roll cages, handles and more are typical for rotary draw benders.
Roll Bender:
Roll benders use three rolls to bend solid, extrusions, tube and pipe to various diameters by adjusting one or two rolls. The pyramid style roll benders have one moving roll, usually the top roll.
Large arcs, circles and spirals are typical for roll benders.
Safety Hazards:
Hand injury.
Avoiding Hazards:
While using the roll bender ensure fingers are located away from the roller as they are being activated by the operator.
Grinder
A bench grinder or a pedestal grinder is a machine used to drive an abrasive wheel or wheels.
Depending on the grade of the grinding wheels it may be used for sharpening cutting tools such as lathe tools or drill bits.
Alternatively it may be used to roughly shape metal prior to welding or fitting.
Grinding wheels designed for steel should not be used for grinding softer metals like aluminium. The soft metal gets lodged in the pores of the wheels and expands with the heat of grinding. This can result in pieces of the grinding being dislodged.
Wire brush or buffing wheels are often mounted in place of the grinding wheels and are used to clean or polish work pieces.
Wire brushes require particular attention for the safety of the operator and bystanders as the metal wires may become dangerous projectiles as they detach from the wheel.
Safety Hazards:
1: Sparks,
2: Metal filings.
3: Noise.
4: Dust.
5: Burns.
6: Wire projectiles.
Avoiding Hazards:
1: Use safety goggles.
2: Use ear defenders.
3: Wear mask if activity is long.
4: Wear gloves as metal being ground will become hot.
Depending on the grade of the grinding wheels it may be used for sharpening cutting tools such as lathe tools or drill bits.
Alternatively it may be used to roughly shape metal prior to welding or fitting.
Grinding wheels designed for steel should not be used for grinding softer metals like aluminium. The soft metal gets lodged in the pores of the wheels and expands with the heat of grinding. This can result in pieces of the grinding being dislodged.
Wire brush or buffing wheels are often mounted in place of the grinding wheels and are used to clean or polish work pieces.
Wire brushes require particular attention for the safety of the operator and bystanders as the metal wires may become dangerous projectiles as they detach from the wheel.
Safety Hazards:
1: Sparks,
2: Metal filings.
3: Noise.
4: Dust.
5: Burns.
6: Wire projectiles.
Avoiding Hazards:
1: Use safety goggles.
2: Use ear defenders.
3: Wear mask if activity is long.
4: Wear gloves as metal being ground will become hot.
Table Saw:
A table saw or saw bench is the most common piece of large woodworking equipment. It is a versatile machinery that consists of a circular saw blade mounted on an arbour driven by an electric motor, either directly , by belt or by gears.
The blade protrudes through the surface of a table which provides support for the material being cut.
Depending on the thickness of the material being cut, the blade can be adjusted up and down allowing the depth of the cut to vary. The higher the blade protrudes above the table, the deeper the cut that is made in the material.
The angle of cut is controlled by adjusting the angle of the blade.
The rip fence accesory isa guide running from the front of the table to the back parallel to the cutting plane of the blade.
The distance of the fence from the blade can be adjusted, which determines where on the work piece the cut is made.
The table has one or two grooves running from front to back, also parallel to the cutting plane of the blade. These mitre gauge or crosscut sled ( a crosscut sled is used to hold the work piece ata fixed 90 degrees angle to the blade).
Safety Hazards:
1: Hand injury.
2: Dust.
3: Eye injury.
4: Noise.
Avoiding Hazards:
1: When saw is not in operation, lower the blade below the table.
2: Use a push stick when making cuts that would require fingers to be near the blade.
3: Never operate the saw ina way that your fingers advance in the path of the blade.
4: Keep the blade guard in place.
5: Wood being cut can be violently kicked back due to natural stresses in the wood which causes the cut to pinch the back of the blade.
6: Wear safety glasses..
7: Wear ear protection.
8: Wear clothing that is not loose fitting and tie back long hair.
9: Wear a mask fitted with the appropriate dust filters.
10: Switch local extraction system on (LEV).
11: Always push the material passed the saw when finishing a cut.
12: The table saw must be adjusted so that the blade is perfectly parallel with the fence and the mitre slots.
Flypress:
A flypress is a metalworking machine used to shape metal by deforming its plasticity. It is feqyently used to punch holes in sheet metal in one operation rather than by cutting the hole or drilling.
A flypress is manually operated.
How does it work?
The manual machine works by using a coarse screw to convert the gross rotation of an overhead handle into a small downward movement with the force multiplied up considerably.
The overhead handle is counterbalanced using a flyweight.
The flyweight helps to maintain the momentum and thrust of the toll as it punch or compresses the material.
If used a s a punch, the tool itself consists of a punch and a matching die into which it closely fits. Both are precision machined and then hardened.
The material is introduced between the punch and the die and the machine is operated.
The punch will cut through the material in one movement by shearing it.
The punch and die may be of any desired shape allowing odd shaped holes and cut outs to be performed.
Safety Hazards;
1: Hand injury.
2: Head injury.
Avoiding Hazards:
1: Do not place hands underneath the top plate of the flypress as the press is being operated.
2: Ensure flyweight is in fixed position once flypress is stopped by operator.
The blade protrudes through the surface of a table which provides support for the material being cut.
Depending on the thickness of the material being cut, the blade can be adjusted up and down allowing the depth of the cut to vary. The higher the blade protrudes above the table, the deeper the cut that is made in the material.
The angle of cut is controlled by adjusting the angle of the blade.
The rip fence accesory isa guide running from the front of the table to the back parallel to the cutting plane of the blade.
The distance of the fence from the blade can be adjusted, which determines where on the work piece the cut is made.
The table has one or two grooves running from front to back, also parallel to the cutting plane of the blade. These mitre gauge or crosscut sled ( a crosscut sled is used to hold the work piece ata fixed 90 degrees angle to the blade).
Safety Hazards:
1: Hand injury.
2: Dust.
3: Eye injury.
4: Noise.
Avoiding Hazards:
1: When saw is not in operation, lower the blade below the table.
2: Use a push stick when making cuts that would require fingers to be near the blade.
3: Never operate the saw ina way that your fingers advance in the path of the blade.
4: Keep the blade guard in place.
5: Wood being cut can be violently kicked back due to natural stresses in the wood which causes the cut to pinch the back of the blade.
6: Wear safety glasses..
7: Wear ear protection.
8: Wear clothing that is not loose fitting and tie back long hair.
9: Wear a mask fitted with the appropriate dust filters.
10: Switch local extraction system on (LEV).
11: Always push the material passed the saw when finishing a cut.
12: The table saw must be adjusted so that the blade is perfectly parallel with the fence and the mitre slots.
Flypress:
A flypress is a metalworking machine used to shape metal by deforming its plasticity. It is feqyently used to punch holes in sheet metal in one operation rather than by cutting the hole or drilling.
A flypress is manually operated.
How does it work?
The manual machine works by using a coarse screw to convert the gross rotation of an overhead handle into a small downward movement with the force multiplied up considerably.
The overhead handle is counterbalanced using a flyweight.
The flyweight helps to maintain the momentum and thrust of the toll as it punch or compresses the material.
If used a s a punch, the tool itself consists of a punch and a matching die into which it closely fits. Both are precision machined and then hardened.
The material is introduced between the punch and the die and the machine is operated.
The punch will cut through the material in one movement by shearing it.
The punch and die may be of any desired shape allowing odd shaped holes and cut outs to be performed.
Safety Hazards;
1: Hand injury.
2: Head injury.
Avoiding Hazards:
1: Do not place hands underneath the top plate of the flypress as the press is being operated.
2: Ensure flyweight is in fixed position once flypress is stopped by operator.
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