About this Blog

This is about the combination of two interests, Radio Control vehicles and Science Fiction models. Its also about vehicle design. The models have to satisfy two main precepts.

1. The vehicles have to work, ie be driveable, but not nescessarily win any races or rock crawling competitions.

2. The main thing is that they have to look cool.

Saturday, 21 June 2014

Tools part 1

I thought I might share some of the tools I use regularly in my model making projects.

Measuring and marking Tools.

I work in metric, specifically in millimetres. I never use centimetres always millimetres. Common materials in Australia are measured in millimetres, even builders use millimetres, a full sheet of plywood is 2400 ( pronounced twenty four hundred) by 1200 ( twelve hundred) millimetres. It makes even more sense for scale models. I generally try to aim for a tolerance of half a millimetre, though anything within an accuracy of 1mm is fine. I encourage anyone who has not done so to move to the metric system, it is so much simpler, there are no fractions to contend with, it is base 10, imperial measurements makes no sense in the 21st century. Australia went metric starting in 1970 and officially completed full metrication in 1988. But why do we still have imperial fasteners in our hardware stores? Because our hardware market is driven from the American market who are strangely still steadfastly clinging to the antiquated imperial system. For a technologically advanced country that strikes me as plain weird. Any way enough of that rant.

Metal rulers are the single most important tool, and they get used for more than just measuring. I have a 600mm (approx 24 inches) , a 300mm (12 inches) and a 150mm (6 inch) metal rule. Sometimes (rarely) I also use a 1000mm rule. Apart from measuring and marking lines, they are used for cutting plastic by running a blade along the edge to score the surface and then snapping the plastic along the score line. More surprisingly they are used for bevelling and scraping plastic. The smaller 150mm rule is most effective for de-burring the edges of plastic sheet or PVC pipe which has been cut.
It can also be used as a scraper to remove seam and mould lines. Generally it is held at an angle and scraped across the edge, removing a thin wisp of plastic. Multiple scrapes can leave a neatly rounded or bevelled edge.

I have a similar range of set squares. These again are used for marking and cutting edges at 90 degrees or perpendicular. You can use a smaller square in conjunction with a longer ruler held firmly against its edge to approximate a larger set square.

I use cheap mechanical pencils with a 0.9 mm graphite. The finer diameters tend to break too easily, where the 0.9mm is thicker, stronger and leaves a strong mark. A fine permanent marker also comes in handy where the plastic may be to shiny to mark with the pencil. A good quality plastic eraser is also useful.

A metal scriber is useful especially when marking out aluminium or brass. A handy tip is to use a permanent ink marker with a broad tip to blacken the metal where you want to scribe it. When you then use the scriber you get a very visible bright mark against the marker black which is many times easier to see than a shiny groove on shiny surface. Once the part is finished the marker ink can easily be removed with iso-propyl alcohol, or methylated spirits. Do not make the mistake ( as I have) of using permanent marker pens on anodised aluminium. The marker dye will migrate into the anodising layer and not come out again. In fact on youtube there are tutorials showing how you can use coloured markers to make coloured anodised parts.

Many of these tools last for a lifetime if kept and used well. The angle protractor and the mid size square I purchased at the very start of my first job as a model maker in 1984, I still use them regularly.

The MITUTOYO vernier calliper was given to me by my first employer as a bonus for good work. I use this almost everyday. It is invaluable for measuring diameters of holes, shafts, drills, fasteners,depth of holes and lengths of small items to an accuracy of 0.1 mm.

There is another very useful tool shown in the pictures above ... the cutting mat. The one shown here was left in a window and exposed to the sun for some time, it warped badly. I tried flattening it with a heat gun and then weighting it but it stubbornly refuses to go back to flat. It is a bit of a nuisance and needs replacing. Get the biggest one you can afford. They don't last forever though and don't leave them in the sun. They can also be used for cutting masking tape into thin strips as the masking tape easily peels off after having been cut.

Cutting, Scribing tools

 The picture above shows my yellow Olfa "snapper" knife. This is the second one I have had over the years. These can be very dangerous if not used with due care. It only takes a brief lapse in concentration, I know from experience, I have a large scar to prove it. Never cut (with any tool) towards any part of your body, always away. If you can't make the cut without risking striking your (or anybody else's) flesh, stop and do the job using another method.

The other yellow handled tool is an Olfa plastics cutter. It is generally used for cutting harder and thicker plastics such as acrylic sheet (perspex). It scribes a v shaped groove in the plastic which can then be snapped when the depth is sufficient. It can also be used to scribe v shaped grooves in the plastic for detail purposes. I have re-ground one of the blades to make a scribing tool that can fit close up to a wall where the original longer blade cannot.

The red handled tool is a razor saw blade which fits in an exacto handle. A razor saw is basically a very thin bladed, fine toothed saw, very useful for cutting up model kits for kit bashing or cutting evergreen pipes. Some people also use them to cut up K&S brass strips and tubes though the teeth tend to get blunt quickly. I personally prefer the Zona saw brand which is much stiffer and less prone to bending, and has a wooden handle. I have recently replaced my Zona saw with three different sizes including a flexible flush cutting version which I have found very handy.  The old zona saws then get moved on to brass cutting duties.

The blue handled device in the centre is a de-burring tool. It has an assortment of blades stored in the hollow handle. It is designed for de-burring metal holes, edges etc but is also very useful for the same task on plastic. It tends to remove more material than using the edge of a metal rule.

A small set of side cutters is good for neatly separating kit parts from their sprues and snipping off lugs, pins and protuberances that are not required.

The tool on the right is the nibbling tool made famous by ILM on many of the Star Wars spaceship models from ep4. The Millennium Falcon in particular is covered in panels that have random rectangular notches cut out of their edges, this is the tool that made those notches. It is designed to cut square holes in thin aluminium panels for electronic hobbyists to fit switches and the like and can generally be found in electronics parts stores. At the bottom you can see a piece of styrene that has had a couple of notches cut out and the bits it removes which could then be used as further detailing although the edges as you can see are a bit furry.

Sanding tools

Some tools you can easily make yourself. Above is a selection of sanding sticks and boards that are simply various bits of wood with wet and dry sandpaper spray glued on. You spray both the surface of the wood and the sheets of sandpaper let it dry a bit and then press the two together so that the sandpaper overlaps the edge of the wooden stick. You the cut around the edge of the sandpaper so that it is flush with the edge of the block. The one on the bottom right is a square stick with the abrasive wrapped over two edges so it can sand a right angle. These blocks are only used for dry sanding, not wet. I only use wet and dry abrasive paper even if I am using it dry. It is usually better quality and doesn't shed the grit like the normal sandpaper, plus you can use it wet if you desire. For plastics, I generally use 80 grit for the course sanding and then 120 grit for finer work, with 180 or 240 if I want it really smooth ( rarely). To really polish plastics shiny smooth you can use 400 up to 1200 grit wet sanded. After that you can use specialist plastic polish or even toothpaste.
Once the sandpaper becomes worn, you peel it off (if you can) and put new stuff on, or just make a new stick or block.
For freehand sanding I tear a sheet into four. One of those quarters gets folded over into three layers which makes a flexible but still stiff pad. With the grit face down you fold one side up and over so that the width is now two thirds and of that two thirds one third is grit face up. Then fold the other side up and over the first side so that only one third of the original width is left, with the newly exposed grit side covering over the first fold. The folds are arranged so that the grit is only ever against the back of the paper, never grit against grit which will ruin the cut of the abrasive quickly. Once one side has dulled you flip it over to use the back. When that side is done you swap the folds to reveal the final third and use that. It can be used this way wet or dry. Plastic responds well to wet sanding as does paint and primer. The wet method results in no dust and keeps the sandpaper from clogging.

Part 2 will look at cutting holes and some power tools.

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