Archive for the ‘Resistant Materials’ Category

Initial knowledge 1

Current working knowledge 2.5

Prior to undertaking the course the most commonly used finishing technique I had in engaged with was sanding in its various guises.  Throughout the year I have had to do this process numerous times, in fact I seem to have spent a lot of time sanding and finishing at one stage or another.  This was not purely to hide mistakes! although sometimes my work has needed a little ‘tweaking’ in order to obtain a better quality aesthetic.  I needed to use glass papering for my plate rack in order to obtain smooth edges on the acrylic.  The process was started by using a  course low grit glass paper such as 80 or 120 and then moving up to the finer grit paper such as 400 where a truly smooth finish begins to be be obtained.  To get an even better finish the highest grade paper I could find was the 1200 grit and this was best used when wet.  I obtained extremely smooth edges and although quite a drawn out process I feel it is worth the extra time to get the desired effect.  To completely finish my edges I used the static buffing wheel.  Although a useful tool and well worth spending the extra 5 minutes to get a truly polished end product my piece of plastic was slightly large and awkward and so the buffing wheel is probably best used with smaller hand held items.  Such as the acrylic key ring I made in year 7 my first ever DT project!

masked off face to avoid scratching

We had a small metalwork tutorial and were introduced to filing as a finishing technique and I had to utilise this when trying to remove some excess material from my aluminium shell.  I marked the area that needed to be removed, unfortunately it turned out to be about 5mm and so I needed to use quite heavy cross filing initially.  This then progressed to a lighter cross filing using a second cut file.  The temptation is to go as quick as you can when filing although it was pointed out that long smooth strokes are much more efficient and this turned out to be the case.  To finish the edge I used the technique of draw filing with an even smoother file and I was able to turn what was a bit of an uneven jagged edge into a much safer smoother finish.  Like with most finishing techniques I found filing fairly long winded but to obtain the finish I desired it was an important process and certainly worth spending the time doing.

Different types of file:

HAND FILE: Used for general filing of metals such as steel. They are rectangular in section and are the most common type of file used in workshops.

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HALF ROUND FILE: Used for filing curved surfaces. A normal hand file with its flat cutting edges is unsuitable for filing curved surfaces. However, the half round file has a curved surface which is especially useful for filing internal curves.

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THREE SQUARE FILE: Is triangular in section and very useful when filing ‘tight’ corners / angles. The sharp edges allow the file to fit into corners when filing.

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KNIFE FILE: Knife files are very useful when filing where there is little space. Knife files are very thin and can fit into small gaps.

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SQUARE FILE: The square file is quite thin and fits into corners well. They can be used to file slots in metal or for filing where there is little space.

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Files are often graded according to the roughness / smoothness of cut. The file that has the least harsh teeth is graded as ‘very smooth’. The most abrasive of files is graded as ‘rough’. Some of the grades of cut are shown below.

http://www.technologystudent.com

Types of Metal Finishing 

Metal finishing is used to treat the exterior of a metal product by applying a thin complimentary layer to its surface.  There are numerous types of metal finishing processes that can be used for a variety of purposes. In this guide, we will review the major finishing methods, as well as applications and considerations for choosing a metal finishing process. Some of the general advantages of applying this finishing treatment to a metal product include:

  • Increased durability
  • Improved decorative appeal
  • Enhanced electrical conductivity
  • Higher electrical resistance
  • Higher chemical resistance
  • Higher tarnish resistance
  • Potential for vulcanization

Metal Plating

metal plated watchMetal plating machines use a chemical bath to coat or alter the surface of a substrate with a thin layer of metal, such as nickel or Teflon. The electroplating method generates an electric current to coat the substrate, while electroless plating employs an autocatalytic process in which the substrate catalyzes the reaction.

Metal plating provides a number of advantages as a finishing process. It can improve a product’s durability, corrosion resistance, surface friction, and exterior appearance. It is also a useful option for coating other metals. In high-volume production runs, a barrel-finishing machine is a fast and efficient plating solution. However, plating machines are generally not suited for smoothing out surface defects.

brushed metal lockBrushed Metal

Unlike plating, brushed metal finishing is an effective method for removing surface imperfections. These finishing machines create a uniform, parallel grain surface texture to smooth out a product’s exterior. An abrasive belt or wire brush is usually employed to achieve this effect. In addition, the singular direction of the belt or brush can create slightly rounded edges perpendicular to the grain.

Buff Polishing

If your project requires a smooth, non-textured finish, then a buff polishing machine may be your answer. This machine uses a cloth wheel to buff the product’s surface, resulting in a high, glossy sheen. The process is often used for decorative products that benefit from luster and smoothness.

Buff polishing machines tend to round out a product’s edges, and due to the cloth wheel’s range limits, the process is less effective for applications requiring intricate, fragile, or recessed features.

Metal Grinding

Metal GrinderGrinding machines use friction, attrition and/or compression to smooth out a metal product’s surface. There are several types of grinding machines designed to deliver different levels of finite smoothness. For example, a ball-grinding mill is an excellent fine grinder for cement products, but may not work for more extensive smoothing projects.

Most metal grinding machines consist of a substrate within a rotating drum. Rod mills are used to make metal rods, while semi-autogenous grinding (SAG) mills and autogenous grinding mills smooth copper, gold, platinum, and silver.

Metal Vibratory Finishing

Vibratory finishing machines are used to deburr products and remove sharp edges. They position material inside a drum filled with abrasive pellets and a substrate, then apply tumbling vibration to create a uniform random texture. The machine’s cycle speed and magnitude of vibration are usually variable, allowing effective treatment for a range of small- to large-sized parts.

worker sandblastingSand Blasting

Sand-blasting machines are typically employed in projects requiring a uniform matte texture. The process (also known as beadblasting) forces sand, steel shots, metal pellets or other abrasives into a substrate at high speed. This results in a smooth, clean product texture, particularly in soft metals.

Powder Coating

Powder coating applies a decorative finish that is similar to paint, but with greater durability. The process involves melting dry plastic powder onto the metal to produce a textured, matte, or glossy coating. A textured powder-coating machine is also highly effective in removing surface defects.

Hot Blackening

Hot blackening machines spread a thin layer of black oxide onto a product’s surface to create a matte black finish with high abrasion resistance. It is a high-temperature process in which the product is inserted into a series of tanks containing cleaners, caustics, and coolants. Hot blackening is most commonly used in the production of automotive parts, tools, and firearms.

Choosing a Metal Finishing Process

There are a few considerations that can help you narrow your choices in selecting a metal finishing technique suitable for your project. Some helpful things to keep in mind are:

  • Production speed: How quickly does the technique apply finish to the product?
  • Cost-effectiveness: Certain finishing machines (such as vibratory tumblers) can be expensive, but may compensate for their price by delivering faster cycle rates
  • Metal hardness: harder metals usually require more intense finishing techniques, like grinding, or may need tougher abrasives than those used on softer materials
  • Potential for vulcanization
Basic metal finishing, Von Fraunhofer, 1976
I seem to have found a friend in the orbital sander,  I found using this tool my preferred weapon of choice when faced with a large amount of sanding to do for my space saving furniture project .  Again it was a case of starting with the  more abrasive paper and working up in grades to obtain a smoother finish.  I liked using this machine as it is able to cover a larger surface area than I could have done by hand in a quicker time, but it is more suited for sheets of material and for more intricate areas you certainly have more control sanding by hand.  There have been times where I have thought  ‘I’ll just use the orbital sander’ to tidy things up but really it should only be used for getting a smooth finish not to hide any sins that may have occurred in production.  By producing substandard work it only leads to more  work in the long term so the key really is to apply quality control to every aspect of the manufacturing process to ensure that time is not wasted having to try and cover up errors.  Fortunately  it was more a case of smoothing the surface of the wood rather than spending hours trying to make my joints look like they fit as regards the space saving unit.  One instance where I nearly reached for the orbital sander was for the tops of my drawers.  After clamping and gluing them I did have one edge that was slightly raised so the temptation was there.  Instead I chose to use a plane and in particular a jack plane.  This tool was by far the best for the job and after being shown how to set up the cutting blade I was able to get a far neater even finish than I would have done by simply holding the orbital sander down in the corner of the drawer!

After a bit of arm twisting I was also let loose on the belt sander to aid with the finish of my dovetail joints, although they were neat, when clamped and pulled in they sat a little proud but the belt sander helped remove the little bit of excess and made the joints look really nice.  I understand why it is locked as I can see it being slightly erratic and it certainly travels at some speed, fortunately though I managed to keep a tight grip and not turn my work into, and I quote Joe ‘ a dogs dinner’.

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R13 Health and safety

Posted: October 10, 2010 in Resistant Materials

Health and safety is of course vital in the workshop not only now but even more so next year when I will be teaching in class.  I have used some of the machinery in the workshop  before and so I have been shown in the past the safe practice as well as in our induction weeks.  I like to think I conduct myself carefully and responsibly when using various machinery and tools but of course appreciate that next year when faced with a class full of students it will be hard but paramount to maintain a high level of vigilance as regards health and safety at all time.  I will use this section to detail the machinery I have come into contact with and also the key BS4163 and CLEAPSS points.  It will also give me an indication of any machines I may need to familiarize myself with before next year if I have not had a chance to use them in any of my projects.

BS4163 (explanation from the website):

BS 4163 is the code of practice that provides guidance for people responsible for planning services, equipment and machinery, and for anyone who may use these in design and technology facilities in schools and similar establishments.

Design and technology facilities include all teaching areas and preparation areas where materials are manipulated and processed, equipment is used and design and/or manufacturing takes place (e.g. food, textiles, graphics, electronics, technology, craft, engineering, manufacturing and computer areas).

The recommendations cover supply and safe use of equipment, machine tools, materials and chemicals, personal protection, and safety management, with particular reference to the hazards involved.

Contents of BS 4163 include:

  • Health and safety management
  • Planning and services
  • Teaching areas, equipment, tools and processes
  • Materials
  • Terms and definitions, and references.

BS 4163:2007 replaces BS 4163:2000 which has now been withdrawn.

CLEAPSS: The exact definition of CLEAPSS is featured at http://www.cleapss.org.uk/about.htm

STRIP HEATER

I used the strip heater to bend the acrylic for my plate rack, I found it fairly easy to use and managed to conduct my work with efficiency and ease with no accidents.  I would feel comfortable using at again and competent enough to show somebody else how to use it.

BS4163 main points for the strip heater:

Hazards:  The hot plastic and hot surfaces can cause burns.Inhalation of fumes.Unstable equipment or work pieces can cause injury.  There is also an electric shock hazard.

Risk control Measures:  Only use appropriate materials.  Simple heat output controllers should be provided.  Guarding provided if practical.  Ventilation provided if harmful fumes are released

Materials to use:
Thermoplastics such as acrylic.  The plastic sheet is heated along the hot wire so it can be folded at a controlled angle.

PPE:
Gloves when touching the hot plastic and masks if any fumes are given off.

CLEAPSS Main points:
Hazards: Burns can occur as the wire gets extremely hot and the plastic can become hot enough to burn the skin.  There is an electrical hazard due to the bare wire heating element.

Risk assessment: The bare wire types use safety extra low voltage and the mains powered heaters are insulated.  The risk of burning from the hot wire is an obvious one so easy to avoid.

Common problems:
Overheating of the plastic causing it to bubble.  Keeping the plastic straight over the heated wire and bending it at the correct angles (especially with large pieces of plastic) can sometimes be awkward.  If fumes are released they may be odourless and go unnoticed so it is advisable to wear a mask.

BAND SAW

I have used the band saw on a few occasions in the workshop for both cutting hard and softwood and the alternative plastic one.  I feel comfortable and in control on the machine but I am certainly aware of the dangers it posesses.

BS4163 Main points:

WARNING. : Students may only use sawing machines  including the band saw when they have been assessed and the assessment has shown that they are competent, and they are under the direct supervision of purposely trained staff.

Hazards :  Long hair, loose clothing, etc., can become entangled in moving parts.  The closing movements between parts can result in trapping.  The  forward motion of the saw (power hacksaw) arm can result in trapping or severe cuts.  The bar stock projecting from the vice can present a tripping hazard. Sawing machines can present a hazard of electric shock. Sharp edges on tools and work pieces can cause cuts.  Blunt or damaged blades can present a hazard.  Contact with cutting fluids, oil and grease can irritate the skin. Inadvertent starting of the machine can present a hazard. Lack of space around the machine can lead to the operator being pushed by passers-by. Slippery floor surfaces or loose items around the machine can cause slips that result in contact with moving parts.  Manual handling of the bar stock can present a hazard.

Suitable materials to use:
Depending on the thickness of the blade the band saw can be used to cut hard and softwoods, acrylic, nylon, foams and if the correct blade is applied thin metals.  It is a useful tool for cutting approximate straight lines quickly.

PPE:
Safety goggles, push stick.

CLEAPSS Main points:
Hazards: Trapping, inadequate guards on band saws present an increased risk.  Fingers or materials can become trapped between belts and drive pulleys or between the blade and a fence or guard.  If material is not held securely then a ‘kickback’ can occur this can also be a result of missing teeth on the blade or the way the material is being cut although this is less likely on a band saw and more likely on the circular saw.  All pulleys, drive belts and saw blades present a high risk unless they are adequately guarded.

Risk Assesment:  The guard must be at the right height for the material at all times.  The band saw can create flying dust so extractors should be on and eye-protection worn at all times.  Contact with any of the moving or rotating parts can cause serious cuts and abrasions and any flying dust can enter the eye.  There is a serious danger of entanglement if the rotating parts are exposed, long hair, jewellery, loose clothing can all become entangled and should be kept away from rotating parts.

Common problems:
The guard must be at its lowest point to allow the material to be passed through it safely and accurately.  If  it is not the blade can bend and snap.  Never attempt to pull material out from the blade, especially if it is moving!

SCROLL SAW

I have used the scroll saw on numerous occasions for cutting both wood and acrylic at tight and curved angles.  I feel comfortable and controlled using the machine although on a couple of occasions I have managed to snap the blade as they are quite fragile.

BS4163 Main points:
Hazards:  Hands and fingers can come into contact with the blade.  Dust can be inhaled.  Inadvertently starting the machine can become a hazard.  The saw can become detached from the bench.  The blade can become detached from the arm.  Any loose items, long hair e.t.c can become entangled in moving parts.

Risk Control:  Ensure all loose items are tied back and out of the way of moving parts.  Make sure the saw is set to an appropriate speed.  Ensure the correct material of the correct thickness is used.

PPE:
Eye protection must be warn, dust extraction used if required and masks worn when cleaning.

CLEAPSS Main Points:
Hazards:  Human contact with any of the moving or reciprocating parts can cause cuts and abrasions.  Vibrations from the blade can cause the machine to move around the work bench.  Efficient dust extraction is required when cutting materials such as MDF.  All loose items tied back to avoid entanglement.

Common problem:
Pushing the material through the saw too fast can lead to the saw snapping.  Ensure all the correct components are tightened and the saw makes a ‘hummingbird’ sound when switched on.  Although one of the safest power tools to use you need up most concentration as anything less than full focus can lead to accidents and in-accurate work

ELECTRIC HAND DRILL


I used the electric hand drill to drill the holes through sheet aluminium for my rivets in the plate rack.  I found it easy to use although at first before I used a centre punch I found it difficult to drill the holes in a straight line, however with the use of this component, drilling was made a lot more accurate.

BS4163 Main points:
Instructions should be given to ensure that users do not touch the rotating part of the drill.  The drill bit must be tightened securely.  Training should be given on deburring sharp edges on drilled material (this was necessary when deburring the holes in the aluminium).

CLEAPSS Main points:
Hazards: Tripping,  power leads can be tripped over although the electric drill I used was cordless.  Entanglement, long hair, loose clothing can get caught in the rotating parts.  Manual handling, heavy work pieces and the gyroscopic effect of rotating motors can present a manual handling hazard.  Flying materials, off cuts, broken drill bits and chuck keys can be ejected violently.

PPE:
Eye protection, apron if necessary

Suitable materials and processes:
Drilling holes in large sheets or big blocks of materials that are not suitable for the pillar drill.  Allows for close and accurate work with added control.

Common problems:
There is a risk that people not used to using the tool could put their hands in hazardous places when holding materials steady.  Making sure the drill is operating at the right speed on the correct material, for something like acrylic it could cause cracking around the hole.  Making sure the drill bit is tight and rotating in the right direction.


CIRCULAR TABLE SAW

I have only actually used this machine once and that was when we were showed how to use it safely in the second week.  It is quite daunting and extremely dangerous if not used with the correct due care and complete attention.

BS4163 Main points: Students should not use the circular table sawing machines, they are considered high risk woodworking machinery.  Only a competent specifically trained person should use the machine and a record of the training should be kept.

Hazards: Hands or fingers coming into contact with the moving blade,  work pieces becoming jammed, clothing getting entangled, fumes or dust being inhaled.  Noise causing hearing damage.  Inadvertent starting  of the machine can be a hazard, blunt or damaged blades can cause a hazard as can withdrawing work while the blade is moving.

Risk assessment: A mushroom headed safety stop button can quickly stop the machine in an emergency.   Fixed guards or interlocked guards that hide the mechanisms.  Electrical isolation must be provided and it must be controlled by a starter incorporating an overload protection and no vault release.  You should be able to lock the machine to ‘off’ when it is not in use.  There needs to be plenty of space around the saw bench so work can be safely handled.  The ripping fence should be set to no more than 50mm beyond the tips of the saw teeth in direction of the feed.  The riving knife should be securely fixed below the table and should be set so that the gap between the knife and the saw blade at table level is the minimum possible.  The crown guard for the exposed part of the saw blade should be rigid and easily adjustable.

PPE

Safety goggles, ear protectors, workshop apron, push stick

Suitable materials and processes

The circular table saw is suitable for cutting man made boards such as MDF and Ply wood and natural woods up to 50mm in depth.  The table (mounted fixed to the blade) has a fine groove to the left side of the blade where the crosscut angle can be moved. This way crosscuts are easily done. To the left side of the blade the guide fence for rip cuts is attached.   A rip cut is a parallel cut along the board sides, to cut the wood equal in width. Table saws with a sliding table allow the user to move the whole table part – left of the saw blade – backwards and forwards. As the entire table is guided on guide brush rollers, even panels of size can be cut easily.  Compared to fixed base table saws the sliding table allows to do cross cuts on a wider board width

Common problems

If the work is not held securely there is a high risk of   ‘kick back’ where the work can be thrown back violently, this can also happen if there are missing teeth on the blade or if the machine is started inadvertently.  Human contact with the moving blade is extremely dangerous and could be as serious as a fatality.  Long hair, loose clothing or jewelery can be entangled on moving parts dragging the user onto them.  Students thinking they can use the machine they must NEVER.

Here are the Pro Formas required for completion of this course:

CAM           Bandsaw           center lathe          circular saw proforma           electric hand drill              fan oven proforma

gas burner proforma          Hand and tablerouter          Hand held Jigsaw          hand tools proforma          Hegner saw proforma

hot glue gun proforma          Morticer proforma          oil saw proforma          orbital sander          pcb drill proforma

pillar drill proforma          Planer and Thicknesser          Portable biscuit cutter          solder iron proforma          strip heater proforma

vaccum former proforma           wood lathe          welding proforma



Initial knowledge 1

Current working knowledge 2

I find smart and modern materials a really fascinating subject.  I wasn’t really aware of many of the new developments before undertaking the course and was first really introduced to them at the Design and Technology fare at the NEC (apart from a decidedly dodgy global hypercolour t-shirt in the mid 80’s).  The amazing thing is that the field is so broad and diverse and could be seen to include anything from nanotechnology to artificial intelligence.  We have been given the chance to interact with them now on a couple of occasions and to me although I do find them fascinating it sometimes begs the question ‘what could we do with them?’  In ten years time the materials that are being developed now could be common place in society and as teachers we could be using them as everyday media in design and technology and so to me this indicates the importance of keeping up to date with new developments but also keeping an open mind as to how one day we might employ them within lessons.  Its certainly an area that I know I would have been really interested in in school and with samples available could well be an interesting focus point for lessons in the future.  Children nowadays are always interested in the newest technologies and it would be interesting to see what ideas their young enthusiastic minds could come up with to apply the new technologies and see if they could find a way to integrate them into their future.  So what sort of things are being produced?

Electrol-rheological fluids – fluids that undergo instantaneous yet a reversible change in structure when subject to electrical stimulus.

Shape memory materials- Metals which when plastically deformed at one temperature will completely recover their original undeformed state upon raising the temperature.

Piezoelectric materials- Solid materials which generate a charge in response to a mechanical deformation or develop mechanical deformation when subjected to an external magnetic field.

Electrostrictive materials- Materials that develop mechanical deformations when they are subject to an external electric field.

Thermal materials- Materials that change in response to an alteration in temperature

Sensing technologies- a device, which responds to an input quantity by generating a functionally related output usually in the form of an electrical or optical signal.

Having looked at many of these materials in different forms it is easy to think that they are a clever invention but view them as just a bit of fun but on the contrary many modern and smart materials perform essential roles in a wide range of different products.  Motion control gels or smart grease regulate the movement of components in contact to provide the right ‘ feel’ or desirable characteristics.  Sliding microscope barrels, variable resistors and even slow spring CD drawers all incorporate motion control gels and it is perhaps the more readily available smart materials that are already in practical use that we could see being available to classrooms in the very near future.  Modern and smart materials are already increasingly available in generic forms for design and technology students and I feel sure that things like SMA’s (smart wire and smart springs), liquid crystal technology (thermochromic film) and things like the control gel will be readily available and cheaper to purchase for schools in the not to distant future so I wil continue to investigate and keep up to date with new developments hopefully consider some applications so that I can make my millions in the future.

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Initial knowledge – 1

Current working knowledge – 2

As a slight novice to computer aided design my experience of computer aided manufacture is limited as well.  Although aware of machines such as the router and laser cutter I have never really had the opportunity to actively explore the potentials of the machinery so the trip to the NEC in Birmingham to the Design and technology showcase was a good education.  There were many of the CAM machines on show and as well as seeing them in use there were some interesting examples of the work that can be produced on the different machines.  After seeing the different machinery and their individual abilities I was keen to have a bit of a play myself and when doing ED217 my lamp was designed to be mass produced and was an opportunity to use the laser cutter.  My first designs were done on 2D design:

whirlpool lights works

I then transferred these designs to the laser cutter and manufactured them in acrylic:

I found the laser printer a really useful manufacturing tool.  After some practice I managed to get the dimensions of the acrylic right and ended up using it to manufacture the main stand of my lamp.

swirl alot word

I will certainly feel comfortable using the laser cutter again and I am well aware of its value in a design context.  There are certainly some interesting and intricate designs you can create with it to a very accurate and polished finish.  Having enjoyed my first taste of computer aided manufacture I will look to see if I can incorporate any of the other machines available such as the router and the 3d printer in any future projects  or perhaps experiment with them in mini tasks to get a more in depth knowledge of the manufacturing processes available as I believe CAD and CAM will have a large part to play in schools now and in the future.

When making my mechanical toy I needed to create 8 eccentric cams out of MDF, they all needed to be the same size and shape so the boxford was the best machine to create uniform cams.  It was a little bit difficult to transfer the design form 2D design to the machine but after help from Dean and double side taping the MDF I finally managed to get them manufactured.

R10 Heat treatment

Posted: October 10, 2010 in Resistant Materials

Initial knowledge -1

Current working knowledge –1

When thinking of heat treatment I immediately think of welding,  I don’t actually have any first hand experience of this joining technique but I did do some research on the subject which can be seen in R6 at the start of the joining techniques section.  I am certainly keen to have a go at welding before the year is out and might organise a short mini task around the subject to give me a basic  grasp.

The heat treatment I have used previously is vacuum forming which I did in packaging design and I will brush up on that before the year is out.  The active heat treatment I have used so far is the strip heater for the plate rack, and the for the 2 part mould.    Both of which I found fairly easy and safe practices to use and would feel confident if required to use them again.  The main point worth noting is to not overheat the plastic as it can lead to the plastic bubbling.  Another thing worth remembering is to make sure the moulds are the correct size, or any template to aid in bending is the right size and angle, because although you can reheat the plastic to near its original form, larger pieces remain slightly warped.

R9 Machining

Posted: October 10, 2010 in Resistant Materials

Initial knowledge – 1

Current working knowledge – 2

A lot of the machines in the workshop do look familiar and I have had a chance to use them in the past.  I have used the pillar drill, buffering machine, band saw, belt sander, orbital sander, scroll saw and wood-turning lathe at some point in my education.  I feel confident with machining but feel I will need to practice with them once more and fully learn the safety features of the machines and familiar myself with safe practice again before moving into schools next year.  I will use this section to explain the functionality and practicality aspect of the various machines whereas section R12 will be used to show health and safety and risk assessment.

Pillar Drill

I am very familiar with this machine, I used it throughout school and it was one of the first machines I used when making the ball-bearing game mini task.

The pillar drill is a common type of machine drill used in many workshops. It is similar to a bench drill because both machines do pretty much the same thing which is to drill holes in a variety of materials such as wood and plastic.  The pillar drill sits directly on the floor and is useful for working with large and small pieces of material.  Because the pillar drill is larger than a bench drill it can drill bigger holes and as well as a twist drill (standard drill bit) used for drilling hole ranging in sizes from 1mm to 14mm.  It can also accommodate a Forstner bit which is used for larger diameter holes.  It is worth remembering when using this bit that the hole is drilled very slowly so that the bit does not ‘jam’ in the wood and also a hole saw. The hole saw is used for large diameters of hole.  The advantage of  this type of drill bit is that the blade can be changed to give different sizes of diameter.

Minimal effort is needed to operate the drill and the angle of the spindle is fixed relative to the table to allow holl to be drilled accurately and repetitively.

The main parts of the pillar drill are:

  • CHUCK –  The chuck holds the drill bit and is tightened and released with the use of a chuck key.  A chuck will usually accommodate drill bits with a shank up to 16mm
  • ELECTRIC MOTOR-  The motors power is transmitted through a V-belt and pulley system to the spindle and chuck.  The induction motor is rated between 187 and 850 W
  • NVR switch- no volt release switch for safety
  • FEED LEVER-  This drops the drill into the material, it is spring loaded but can be clamped to run the drill at a lower position to enable the user to work with both hands
  • THROAT- The distance between the worktable an column, the larger the better for added flexibility.
  • SAFETY GUARD-  This shields the chuck, it stops loose items getting entangled in the chuck and protects the user from flying debris although with some smaller items it can get in the way.  It would also prevent the chuck going round if the key was accidently left in.
  • WORKTABLE- Cast metal and attached to the column with a cantilever it has a hole in the middle to allow the drill to go through any work without damage to the table.  The worktable can be tilted to 45 degrees on some machines and can be moved to a side to accommodate larger work pieces.  Fences, vices or jigs can be bolted into the slots on the table.

Pillar drill 1.  Locking lever

2. Chuck

3.  Safety Guard

4.  Worktable

5.  Worktable lock

6.  Column

7.  Feed Lever

8.  Enclosed pulley levering

BUFFING MACHINE

The first time I used this machine was making a rather fetching acrylic keyring for my first ever project for DT in year 7.  It is easy to use and I employed it when buffing the edges for my plate rack after I had glass papered and wet and dried the edges of it.  By applying a small amount of polish to the buffing cloth it can produce a fine smooth finish.  It is important to hold the work with both hands as the wheel spins extremely rapidly and you don’t want to send the work into orbit.  It is a fairly straightforward machine to operate and the danger comes from not holding the work tightly.  It is also worth noting that it is wise to use the width of the buffing cloth to polish the work and to move the work in an up and down motion as if you keep the work still it will wear out the buffing cloth.  There is also an emergency stop button on the bottom of the machine that can be foot operated.

BAND SAW

I have used the band saw many a time in the workshop already.  It is an extremely useful machine that allows for the accurate cutting of straight lines in a wide variety of materials.  I have cut large sheet acrylic and smaller pieces on the metal band saw.  I have also used the wood band saw on many occasions for pine, ply and various other woods.  I am competent and confident on the machine but recognize that it can pose a severe danger in the workshop (see health and safety).

Band saws have a serrated metal band that is held in place by two pulleys.  The pulleys allow the band or the ‘blade’ to move around in a circular motion.  The material is fed slowly into the band causing a neat cutting line, it is run on an electric motor and can have one or more running speeds.  For every type of material there is a suitable cutting blade ( as Let me know when cutting acrylic on the wood one, I think the word used was ‘moron’), and therefore the blade can be changed and tuned for the appropriate material.

There are many different types of blades, a regular tooth band is most often used for cutting wood.  A skip tooth blade is best used for cutting pieces of soft woods and a hooked tooth blade is made for cutting through pieces of hard woods. You can also purchase a special diamond blade that is able to saw through pieces of glass. And, there is a hardened blade that can cut through metal. These blades come in varied tooth sizes, tooth shapes and band material.

By using the proper type of blade, you can cut almost any type of material, including soft wood, hard wood, thin steel, copper, conduit, metals, glass, galvanized pipe, and PVC pipe. Once you have chosen the proper band saw blade, and have installed it,  it must be adjusted and positioned on the center of the pulleys. The tension of the blade should also be tight enough to keep the blade from slipping.

The different parts of the band saw are:

  • BLADE-  The band saw blade is a long, flexible band with teeth on one side. A variety of blades are available, including fine-tooth blades, metal cutting blades and diamond blades.
  • BLADE WHEELS-  The blade is wrapped around an upper and a lower wheel. The blade is set in the wheels’  tracks to keep the blade from slipping. The wheels spin to revolve the blade for sawing.
  • BLADE WHEEL COVERS-  The blade wheels are enclosed in a metal cover that guards the blade and other internal mechanisms. The metal covers include doors for access to the blade and wheels.
  • BLADE GUIDE-  A small guide hovering above the table encloses the blade and functions to keep the blade steady as it revolves. The guide includes an adjuster knob for raising the guide up and down to accommodate different material thicknesses.
  • BLADE TENSION ADJUSTER-  Band saws have a tension adjuster knob or screw associated with the top blade wheel. The adjuster is turned for loosening or tightening the tension on the blade.TABLE-  The table is located between the two wheels with the blade running through a slot in the middle. Most tables have a bolt underneath, which is loosened to set the table on an incline for making angled cuts. The table also has a groove for the optional use of a miter guide.

SCROLL SAW

I have used the scroll saw on a number of occasions, again it was one of the first bits of machining I did in the workshop when cutting acrylic for my my ball bearing game.  I used it again to cut the handles out for the sides of my plate rack as I could cut the shaped holes out accurately.  I seem to remember the scroll saw being a popular tool to use in school and it was one of the first electric machines we were allowed to use.   Because of the thin blade it is important to be quite delicate with the material you are cutting when feeding it into the blade.  If you push too fast the blade can snap quite easily and admittedly this did happen to me on one of my first attempts.  It is relatively easy to use but I think the key is patience really.  It only needs a gentle push and when I found that there was resistance from the blade and it was vibrating the material it meant that the blade needed changing.  If any sideways pressure is put on the material you can see the blade bending but it can be quite easy to do so it’s just a case of relaxing the pressure.  The blades range from 1-12 with a 1 being for more delicate cuts.

CIRCULAR TABLE SAW

In the first week Bhav showed us how to use the circular table saw, as yet I haven’t needed to put it into practice.  At school we were not actually allowed to use this piece of machinery and if we needed to use it it was left to the teacher or technician.  Before I used it I had images of me cutting my arm off but if used in a safe correct manner it should cause no danger although its’ potential is evident.  It was fairly easy to use  and would be ideal for cutting man made boards like ply wood and MDF and natural woods up to about 50mm thick.  I found that using 2 push sticks was the safest method as I certainly didn’t want to get my fingers anywhere near the rotating blade.

The table (mounted fixed to the blade) has a fine groove to the left side of the blade where the crosscut angle can be moved. This way crosscuts are easily done. To the left side of the blade the guide fence for rip cuts is attached.   A rip cut is a parallel cut along the board sides, to cut the wood equal in width. Table saws with a sliding table allow the user to move the whole table part – left of the saw blade – backwards and forwards. As the entire table is guided on guide bush rollers even panels of size can be cut easily. Compared to fixed base table saws the sliding table allows to do cross cuts on wider board width.

Metal lathe 

The metal lathe is an extremely useful tool for turning metal. Also like all power equipment it can be very dangerous if not operated with caution. The term used in cutting metal on an engine (metal) lathe is “turning” for obvious reasons as the piece of metal in the machine is being rotated and the cutting instrument (tool) is stationary.

Most engine lathes come equipped with a three (3) jaw chuck but some have a four (4) jaw.

There are three most important elements of using an engine lathe to understand the use of the chuck, the tool post carriage and cross-slide and the tailstock.

The Chuck

The chuck is directly attached to the drive mechanism of the engine lathe and rotates at variable speeds up to as much as 6500 rpm on some machines. To start, clamp the piece of metal to be turned in the chuck, the three-jaw chuck is self centering, however since pieces of metal are not always perfectly straight and level it is recommended that you use a dial indicator to check the location of the piece of metal in relationship to the machine. This can be done by placing the indicator on top of the tool post with the dial stem touching the part and with the machine turned OFF and in neutral position rotate the chuck checking the trueness of the part within one or two thousands of one inch.  This is a precision machine that can make cut to sizes within that tolerance or better. Once you are sure that the part is true, tighten the chuck as tight as you can place the chuck key in each key receptacle on the side of the chuck. Check once more for true and then place the chuck key on the workbench away from all moving parts.  Never, leave the key in the chuck except when using it to tighten the part in the chuck. The key can become a flying chunk of lethal steel if left in the chuck and the machine is started into motion.

 The Tool Post Carriage and Cross-slide:

It is self explanatory that this is where the cutting tool will be located. The cutting tool, for safe and efficient cutting the tip of the tool must be located direct on center of the part in the chuck, too high and the base of the tool will drag on the part deflecting the depth of the cut and too low the tip will tend to gouge and/or cut too deep. If you are not familiar with using an engine lathe, It isrecommended that you use the lower speed of chuck rotation and take shallow cuts until slowly increasing the rpm’s until the tool cuts smoothly and does not appear to heat up, this can be seen by the tip discoloring to a blue tint when no longer cutting. The depth of the cut is regulated by the dial handle on the cross-slide of the carriage, the tool post is mounted here, each line on the dial of the handle of the tool post (small wheeled handle) is equal to either 1 one thousands of an inch or 2 one thousands of an inch. With the part rotating at a moderate speed touch off the tip of the cutting tool near the end of the rotating part, very slowly ease the tool towards the part until it just touches, as witness there will be a very fine hair like shaving on the cutting edge of the tool and back the carriage off from the part (using the large wheel on the carriage) without removing the tool from its position. The set the indicator marks on the dial to the Zero mark.

The carriage moves along the ways (the metal tracks) to and away from the chuck, the cross-slide move to and away from center or the part. There are two other handles (lever like) on the carriage these are the power feed handles. One feeds the carriage toward the chuck at a predetermined speed and the other feeds the cross-slide. To understand the operation I recommend you test these operations without a part in the chuck at the different speeds of feed to get the feel of the action of the machine.


The higher the speed, within reason to the size and weight of the part, and slower the feed combined on most chromoly steels, if you are not sure test speed and feed combinations on a scrap piece of the same metal you will be turning.  Be sure to stop the motion of the carriage before coming into contact between the chuck and tool post, this can damage either or both part as well as being dangerous to your safety.

When cutting metal it does heat up, heat can damage both the part and the cutting tool, the use of water soluble oil mix with water or light cutting oil sprayed on the part is recommended to extend the life of the tool and keep the part from creating hard spot from over heating.

Tailstock:

The Tail Stock is located on the opposite end of the engine lathe from the chuck, mounted on the ways of the machine. The tail-stock has limited uses, the most common is to drill out the center of the piece of steel in the sleeve of the unit you can insert a “Jacobs Chuck”, a chuck like on your hand-held power drill, and can be fed into the rotating part using the wheel at the outside end of the tail-stock. The other general use is for a live center, the cone shaped object with a tapered tang shaft that fits into the sleeve, and the cone portion spins on ball bearing internal mechanism. This is used to fit into the center hole of the work piece holding it firmly between the tailstock and chuck.

Before feeding either the drill chuck or live center into the moving part, be sure to lock down the tailstock into position by tightening the screws at the base of the unit or the tension lever, they come equipped either way.

Cutting Threads:

The thread cutting lever  is referred to as the half nut. On the backside of the carriage you will see a dial with four number and marks, these are you engage marks. It is hard to explain fully but in generalities, for even numbered threads as in ¼ “20” use even numbers for odd numbered threads the odd numbers.  The half nut and the carriage will take off at a high rate of speed. So when threading, do not use high speed, the feed relationship is direct to the rpm’s the part is rotating. Reminder: this is just a general description of the threading process and it is recommended that you seek direct hands on instructions.

Until you get use to the operation of the piece of machinery test at various speeds and feeds. If you get a long stringy cut instead of a chip increase feed until material comes off in chips. Keep the ways and carriage clear of chips from cutting, do not use your hands use a small brush; the chips can be HOT and are extremely sharp and can cause injuries. Always wear Safety Glasses and keep your hands away from moving parts of the machine. These are just the basic safety practices. And as with any shop always keep your work area clear and clean.

I have used this machine for the plumbob mini task.  Unfortunately when drilling the hole I managed to snap the drill bit.  When moving the tailstock hand wheel it was suggested that I turn it just a quarter at a time to avoid doing this again.

Router table

In general, a router table will help you work with stock of dimensions that don’t lend themselves to handheld router work.   I attempted to router the rebates and grooves on the timber for my space saving unit but I found it a little hard to control so I decided to use the table router.  Long, narrow stock, such as that used to make moldings and trim are nearly impossible to work with a handheld router. Edge profiling a few hundred feet of a particular door or base molding could probably be done with handheld router and the aid of special shop-built rigging, but dong so would be an extremely inefficient choice, when a router table makes long runs of narrow stock routine.

Small pieces of stock are also a challenge to work with a handheld router. Handheld work on small parts often involves a difficult balancing act. You have to keep the router perfectly upright on stock that doesn’t do a good job of supporting the router base. To compound the problem, you have to have a way of holding the stock itself in place while you work. A router table leaves both of your hands free to hold on to small parts while the table surface provides a sturdy, flat support for the entire surface of the workpiece.

Trimming the edge of a piece of stock to a flat, smooth, square surface or exactly following the contour of a pattern is one of the router’s specialties. Attaching a straightedge or a template to a piece of stock is one of the quickest and most effective ways to clean up an edge, or to perfectly and repeatably form the arched top of a frame and panel door or any other curved part.
Using a router table for edge trimming and pattern work speeds the process by eliminating the need to hold both the workpiece and the pattern down while you make the cut.

The router table surface supports the workpiece very well. With a handheld router, the door would have had to be clamped down a work-surface in preparation for the cut, and considerable care would have been required to keep the router surface flat on the surface of the wood.

R7 Shaping techniques

Posted: October 10, 2010 in Resistant Materials

Initial knowledge 1

Current working knowledge 2.5

I have used various shaping techniques throughout my education these were mainly orientated around wood and sign foam,  my aim for the year is to try to use as many different techniques in as many different materials as possible and to brush up on the ones that I have previous knowledge of.

I have turned wood and foam before using the lathe but it was some  time ago.  I took the opportunity to watch Les demonstrate wood-turning, which I found useful as it certainly jogged my memory as regards technique, the tools to use and health and safety issues.

I remembered that the top variable speed belt must be the same on the corresponding pulley, and that a cap must be placed on the end that you are using.  A centre point then needs to be put in the centre of the piece of wood to be turned using a hide mallet (the driving centre), and the wood is placed on the lathe ensuring that the wood does not touch the tool rest when it spins.

There are different tools that can be used including tool scrapes although they have no cutting edge.  Long and strong gauges, thumb and jandle guage and slim parting tools.

Once you start cutting into the wood its advisable to stop and move the tool rest closer to the wood as it shapes to be able to maintain control of the specific tool you are using.

I have used the wood-turning lathe before and I was quite comfortable in doing so, however there maybe the opportunity to use the technique, perhaps more elaborately in the future.

For ED216  my aim has been  to be taken out of my comfort zone using materials and techniques in shaping that I have not previously used.  For instance my plate storage unit has a plastic interior drainage system, I wanted it to be one solid piece of acrylic in case I wanted to make it removable,  so I had to use the strip heater.  Basically this meant I had to heat the long edges I had marked out and then bend them into position.  Prior to using the heater I ran a small test making a simple toothbrush holder out of the same acrylic.  I included some of the tight angles I needed for my plate rack in order to get an idea of what I was going to do.  I have to be honest and admit that the tooth-brush holder came out fine as it was more an exercise of finding out how the acrylic bends.  The piece aimed at fitting in my plate rack was a much harder task as it was a single piece of acrylic approximately 500mm in length and about 1110 mm in width to get the angles correct.  Because of the way the angles bent in to one another made the task extremely difficult and I had to explore ways of holding the plastic at different angles and wrapping it round anything vertical and straight, even the table leg which probably isn’t the most orthodox way of achieving a 90 degree angle!  The actual shape turned out as well as I had expected although on second glance one side was about 4 mm out and so the lid for my rack would not have been straight.  This led to me re-heating one of the edges and trying to shape it round a piece of wood I’d made to fit which in turn cracked the acrylic slightly, so for my next attempt, I made pieces of fitted wood for the angles and as a result got a much better result.  Hindsight is a wonderful thing and it was a bit of a case of ‘and what have we learned?’  I certainly won’t jump in at the deep end again but I would feel extremely confident shaping plastic in future, and probably not on such a large-scale.  Other experience I have gathered as regards shaping plastic was in the first couple of weeks making the 2 part mould to go with my previous experience in vacuum forming.

My first attempt next to my practice toothbrush holder, also the scale next to the strip heater

My next shaping technique in this process was to make the aluminium shell for the acrylic part of my rack,  so after I had clearly marked out almost a box net shape using pencil, a steel metre rule and an engineers square I had to cut out the shape.  For this I used the large metal guillotine and after re-jigging a couple of the lines to allow space for the blade which leaves around a 3 mm gap in the metal, I set about cutting the sheet.  I was actually surprised at how easy it was, I did not have to apply a lot of pressure and the lines were clean and I certainly obtained my objective of using this piece of equipment with no errors and I would feel comfortable using it again.

My piece of sheet aluminium and my second attempt at the acrylic bending

The next stage and indeed another shaping technique I had not previously used was to actually bend the sheet aluminium into the required box shape.  Although I am aware of the other ways of bending metal such as spinning, the shape and size of my piece of aluminium would not allow to use such methods, and so I required a method using strong steel bar and clamps.  By placing the bar along the line I wanted to bend the metal at and clamping it tightly, I was able to bend the metal vertically to as good a 90 degree angle as I could probably get by hand, and thus move the sides to their required positions.  The trouble came when I wanted to bend the third and largest side as I had already bent the 2 sides into place.  The problem was overcome by cutting a piece of right-angled bar to fit in between the two sides and allow space for the joining flaps, then bending it to meet the other sides.  Overall I found this technique effective and not too difficult, although I am now aware that to bend small widths of materials such as joint flaps is difficult and almost impossible by hand, especially if the width of the piece of metal is very small.  Such as a 10 mm flap which had to be removed completely.  I would be confident to recreate and teach this process although it was a relatively easy shape and my next aim is to shape metal using the lathe.

clamping the aluminium to bend the final side