Tools for measuring and marking-out

This is the first part of an account I’m putting together of tools I’d recommend for small-scale making. Once completed each part will be previewed as a post and then put in the Methods section under Recommended tools for small-scale making where I can add to them as I learn new things. The tools will be grouped according to general tasks .. measuring and marking-out; cutting; assembly; shaping and modelling; creating surfaces; painting.

I’ve collated these accounts together from what I’ve already written on this site or elsewhere, but I’ve also added quite a bit to them. The list includes some simple, custom-made tools which can’t be bought, and I’ve added more information on where others can be found. Obviously this list reflects the way I prefer to work, which may differ from other people .. I prefer to use hand-methods rather than machine tools on the whole, but I’ve also kept to the use of hand-tools in my teaching because most of the people I teach don’t have power tools or workshops.

A tool is any device, however simple or however complex, which enables or contributes to the performance of a task .. in this case the task of making. Even temporary constructions to assist assembly, or one-off templates to achieve a specific shape, are tools, and that’s why I’ve included them.

This first part deals with tools for measuring and marking-out and deals with pencils, rulers (including scale rulers), squares, small drawing-boards, spacing or shape templates and other geometry tools. It also covers tools for weighing or dosing materials.

Mechanical pencil

This is the usual name for it now .. a very thin graphite stick or ‘lead’ housed in a mechanism which allows it to be advanced forward as it wears down, without the need for sharpening .. but I’ve also seen ‘automatic’ or ‘clutch’ pencil referred to, and in the UK the old-fashioned term ‘propelling pencil’ is still sometimes used. Some luxury versions can be expensive, but others are as cheap as £4-5 for a pack of 10. These more general-purpose ones most often have a 0.7mm lead with a standard ‘HB’ hardness and it’s also usually possible to refill them.

It is essential to use one of these for fine-scale work, to make a consistently even, fine line when marking-out for cutting etc. But this doesn’t need to be an expensive one .. the cut-price ones from supermarkets will do almost as well. I personally prefer to use a special type though which takes a 0.3mm ‘H’ lead, finer and harder than the usual ones, which gives better accuracy. But I always try to keep this at home, and use other cheaper ones out-and-about or for other general-purposes because pencils are notoriously easy to lose!

Where to get and what they cost

Ryman £4.99 for pack of 10 ‘Papermate Non Stop Mechanical Pencils’ 0.7mm lead; Rotring Tikky 0.5mm £3.99; Zebra Drafix 0.3mm £4.99

Tesco £5.30 for pack of 10 ‘5 Star Disposable Mechanical Pencil’ 0.7mm lead (three leads included with each)

Metal rulers

I deal with these both here and in the next part on tools for Cutting because they are used as much to assist cutting as for measurement. In fact, I hardly use the smaller metal rulers for anything else since the markings on the scale ruler, above, are much clearer to read than the reflective surface of steel rulers. Metal rulers are not generally expensive, although the ones which have a nicely finished edge (smooth and with the raised burr taken off) often cost a bit more. The extra cost can be worth it .. cutting is made easier because there’s less friction between the metal edge and the scalpel blade.

Over the years I’ve come to rely on having four .. a broader 1metre aluminium ruler and a 60cm flat steel ruler for larger work, a 30cm, and the smallest with is 15cm. Especially when cutting, it is useful to have the smaller ones because they’re much easier to handle and move around when working on small work. The aluminium ruler has a rubber grip on its underside to stop it slipping and I cover the underside of the steel ones with masking tape which works almost as well. In the past I’ve tried rulers lined with cork (which are commonly available), but this raises the marking/cutting edge up too far I find, making it possible to ‘undercut’ with the pencil or knife blade if one’s not careful. I have also tried smaller rulers in aluminium, which are also common, but the soft metal is very susceptible to denting and can even be accidentally ‘shaved’ with the scalpel!

Where to get and what they cost

greatart.co.uk Rumold Stainless Steel Rulers inc. VAT 15cm £1.40, 30cm £2.10, 60cm £12.95, 1metre £24.50. Rumold is a reliable German brand, calibration includes (on one edge) half-millimetre measures. There is a choice of either lighter 0.5mm thick rulers or 1mm thick, varying prices. £16.95 ‘Aluminium Ruler’ 1metre with non-slip plastic base.

Scale ruler

Some very basic reductions in size, such as half-size or ‘1:2’ or tenth-size ‘1:10’ in metric, can be worked out in-the-head or with a normal ruler, but others such as 1:5, 1:25 or 1:2500 are more difficult. At some point in the past someone had the bright idea that having, as it were, a miniaturised version of a long tape measure to read from would save a lot of time .. and so the scale ruler came to be. Most people who regularly have to model or draw in scale use one of these to avoid mistakes even when the reduction is a simple one.

One can’t get just one type of scale ruler which will enable working in any scale (big or small) and any unit of measurement (metric or Imperial). Instead there are separate types. Usually you will find one type for ‘big’ scales such as 1:10 or 1:25 especially suited to interior design or theatre design .. and separate rulers with 1:12 or 1:24 scales if you work in feet and inches. Then there is the other type for ‘smaller’ scales used in architecture or landscape mapping, such as 1:100 or 1:2500, and these will also have their separate Imperial equivalents. You notice that I refer to a scale that involves less of a proportional reduction in size .. such as 1:10 .. as big and a scale that involves more reduction in size .. such as 1:100 .. as small. This is, I believe, the correct way of referring to them, because we naturally think of a 1:100 model as being ‘smaller in scale’ than a 1:10 model! People can get very confused about these terms though .. and it is usually the result of confusing ‘scale’ with ‘size’. One needs to think about them separately.

So let’s look at a standard scale ruler suitable for working, for example, in 1:25 scale and see how it helps. Above is the most common and easiest type, a ‘triangular’ rule which is able to present six different scales for us, one on each of it’s six edges.  These scale rulers usually include 1:20, 1:25, 1:50, 1:75, 1:100 and 1:125 ( the 1:100 ‘scale’ is basically just a regular centimetre rule in which the centimetres can be read as metres. In any event it’s useful to have a regular rule included ). The usual plastic type above has a different colour (green, red, black) to assist in finding the relevant face more quickly. I prefer working with this type of scale ruler (rather than the more elegant looking flat type) because they’re less easy to lose amongst the clutter of the work-table! These normally cost between £5 and £10 in the UK at the moment if bought in a shop .. a little less online. The metal one behind it, found in a cheap DIY tool shop, costs a lot less and does its job just as well, but the calibrations wear off a lot quicker because they’re just printed on rather than incised.

Both clearly show the scaled size of 1metre, 2metres and so on .. up to 7.5metres. Both clearly indicate 50cm divisions and the smaller divisions after that represent units of 10cm. The very smallest divisions within those .. this is important to remember .. represent 2cm each, not 1cm since this would be too small to display. With the right scale ruler to assist, working in scale really should be as simple as reading from a regular tape measure.

But unfortunately one might have to hunt around a bit for the right scale ruler to use, if you prefer to buy from a shop. Many art or graphic supply shops stock them but there may be more demand for the type shown above (which is also available in the triangular form) which is calibrated for working in much smaller scales. The numbers along the 1:2500 scale above are the number of metres represented and the smallest divisions therefore represent 2 metres. This can be used for 1:25 work in place of the proper scale ruler because the calibrations work out the same .. one just has to think of it as representing centimetres rather than metres. So ’100′ on this readout becomes 100cm in other words 1 metre at 1:25 scale. A lot of people find it no problem to mentally switch, but it’s certainly much easier to misread or make other mistakes using one of these and it certainly doesn’t help that there are also usually two different scales cohabiting the same edge, as you can see here. I would recommend that if you can’t get the ‘quality’ scale ruler in exactly the scale you want it’s better to go online, or go for a cheaper metal one. In the UK I’ve seen these in £shops and Maplin, sometimes Robert Dyas and B&Q.

I’ve mentioned already that the divisions on a scale ruler are much clearer to read than on a metal ruler .. which reflects too much! .. so I almost always use the ‘1:100’ on the scale ruler for full-scale measurement (at least, up to 30cm). I generally only have the metal rulers for cutting against.

If you want to read more about working with scale rulers and generally getting to grips with the concept of scale go to the article ‘Working in scale’ in the Methods section.

Where to get and what they cost

amazon.co.uk £4.45 ‘Helix 300mm Metric Triangular Scale Rule’ colour coding, doesn’t list which scales are included, but looks like architectural scales;  £5.49 ‘1:20 1:25 1:50 1:75 1:100 1:125 Plastic Triangular Scale Ruler’ colour coding, looks fairly good quality, distinct scales/easy to read;  £2.22 ‘Silverline Tools 731001 300mm Aluminium Scale Tri-Rule’ distinct scales i.e. 1:10, 1:25, 1:50 etc, not colour coded. This is cheap because the calibrations are just printed on and they will wear off in time!

WHSmith £4.99 ‘Helix Tri-Scale Rule 30cm’ combined scale readouts 1:1 – 1:2500, can be more difficult to interpret.

Staples £5.48 ‘Staples 30cm Scale Rule’ colour coding, combined scale readouts, as above;  £5.59 ‘Linex Triangular Scale’ aluminium, distinct scales 1:1-1:125 not colour coded. May suffer with wear, as above.

Making a customised scale ruler

There are some commonly used scales that you are unlikely to find on any of the manufactured scale rulers .. for example 1:12 standard ‘dollshouse’ scale or 1:6 often used in stop-motion animation. For these scales a normal feet&inches ruler could serve well (and it is partly for that reason that these scales have persisted). But on the other hand this doesn’t ‘serve’ completely, because it’s rare to find a normal Imperial ruler where the inches are divided into twelfths .. and in any case it’s no help at all if you want to measure in metric!

In these events it’s good to know that making your own ‘custom’ scale ruler for unusual scales is relatively easy! Above are some examples, and it’s pretty clear how these are done .. by photocopying the surface of a regular scale ruler but reducing or enlarging at a certain percentage. For example, for the customised 1:6 scale above I’ve converted 1:10 calibration (it’s written as 1:100, just ignore that) in which 1cm on the ruler would represent 10cm in the model, to 1:6 in which the same 1cm on the ruler would represent 6cm in the model. The ‘destination’ value i.e 6 needs to be divided into the ‘start’ value i.e. 10, giving 1.666. This is then multiplied by 100 to give the percentage of (in this case) enlargement on the copier, which is rounded off to 167%. This very slight rounding off hardly matters in terms of accuracy. I usually spraymount this onto a card or plastic strip so that it will last. It’s important when using it that you’re very sure about what these calibrations now represent .. for example you might want to mark the ‘1, 2, 3 etc’ here as ’10, 20, 30 etc’ to make it clear that they now represent centimetres.

If you want this method of conversion expressed as a kind of formula see ‘Working in scale’ in the Methods section.

Try square

Unless they see it spelt, a lot of people assume that the name of this tool is ‘tri-square’ (and sometimes it’s even spelt that way, which is wrong) .. the ‘try’ comes from an old usage meaning ‘to test’. The try square is both for checking and marking out right-angles. It is absolutely invaluable .. I’d say indispensable .. for checking the right-angles on wall pieces and then drawing up repeated verticals or horizontals for doors and windows, as shown below. It can be used in much the same way as a T-square would be used against a plain drawing-board.

Never assume that a sheet of card (or especially an off-cut of card) has perfect right-angles even if it’s straight out of the shop. These need to be checked first. Laying a set-square over the corner is often the way that people check but because plastic set-squares are transparent one has to strain the eyes a bit to see this and it may not be sufficiently accurate. Using a try square is a clearer way of checking.

The best try squares for model-making work are the smaller type. The one shown here is more properly termed an Engineer’s Try Square being very precisely and smoothly machined and finished. These will remain true, whereas carpenter’s try squares, often bigger, have a steel ‘blade’ (the part drawn against) and a wooden stock (the part held) and the rivets that bind the two parts can sometimes become loose in time. Try squares are specified by a measurement, sometimes referred to as its ‘reach’, which is the length of the blade not including the stock.The all-metal try square shown here is a comfortable size for small-scale work, with a 100mm blade. For most small-scale work, unless habitually very small, there’s not much point in getting a try square less than 100mm.The most common size for larger try squares is 250-300mm. Bigger than that, and they can become a bit cumbersome to handle.

When buying the cheaper kind of try square (usually medium-size 23-30cm and composite make) I would strongly recommend checking it before buying if at all possible. The best way to check it is to position it against a straight edge of card, draw a line, turn the try square around and check that the blade still lines up with the drawn line. If buying online it helps at least if it states that it has been checked in accordance with BS3322 specification.

With most good-quality try squares the metal of the blade is tempered to make it harder. Some have an angled stock, as shown second from top below, which enables them to be positioned at a 45degree angle for marking mitres (this is more common in the bigger, woodworking try squares). I made the white one myself, cutting a strip of 5mm Palight Pvc for the stock and a strip of 1mm styrene (which is tougher) for the blade. I bonded these together using superglue, positioning the pieces against the corner of the cutting mat for a true right-angle.

The photo below (from Wickes) shows a so-called combination square. The ‘blade’ in this case is a 300mm steel ruler which can be removed from the stock and used separately. When used as a try square the stock can be positioned at either end to use the 45° angle or the right-angle. It often also has a built-in spirit level. Many of these combination squares are fairly cheap and therefore not finely machined. As a consequence there may be a little too much movement between the two parts and the accuracy needs to be checked.

Where to get and what they cost

4D Modelshop £6.20 101.6mm all-steel engineer’s try square (Silverline)

Wickes £8.99 ‘Carpenters Try Square’ 150mm. Traditional design with wooden stock; £9.69 ‘Combination Square’ 30cm, cast metal, repositionable, with built-in spirit level (see photo above).

Homebase  £4.99 ‘Try and Mitre Square’ 200mm, yellow plastic stock, steel blade

Small drawing board

It can be very useful to have a small drawing board, i.e. one just large enough for working on A4 sheets of paper. I’m a firm believer in drawing up everything I make, however small, at the very least to test and ponder over the design before starting to make. I usually only need a small area for this but I also want the means of drawing reliable parallels or right-angles, and setting up the larger drawing board just for this is a hassle! Simple wooden boards for this purpose can be bought, but they’re not so easy to find and can be expensive for what they are. A good, solid piece of MDF can be cut to size at, for example, B&Q but there is no absolute guarantee that the edges will be perfectly smooth and straight.

On the other hand small kitchen chopping boards like this one are common and very cheap. I bought this tough polyethylene board at Tesco for about £1. Its corners are true right-angles and the sides are perfectly straight and smooth. The surface is also smooth but masking tape will grab on it for securing a sheet of paper.

The try square I am using here for right-angled drawing is a little too big and cumbersome. A smaller one i.e. 300mm would be better. I would advise taking a try square to the shop if you buy a board to check for straightness and smoothness, also a piece of A4 paper and a pencil to test the surface smoothness when drawing. Some types of plastic cutting board have a slightly textured surface, meant to grip better, and it may mean that a sheet of thicker paper should be put underneath the drawing paper when working.

Spacing templates

An example of what I mean by this is shown below. I often work in 1:25 scale but in the past, whenever I needed to do brickwork, I always needed to remind myself about the size of bricks and use a scale ruler to divide up the surface for scoring the pattern. This was unnecessarily time-consuming, each time, considering bricks have remained the same size and patterns for hundreds of years. So after a while it finally dawned on me that I should just invest a little time to draw up some accurate, scaled pattern templates and use these to transfer spacing marks to the surface instead of having to measure up each time. I’ve spraymounted this one to 1mm Pvc so that it will last.

Shape templates

Most people will be familiar with the circle or oval drawing templates shown below, even if never having used them. Most art or graphics materials shops have them. The small-circle template is particularly useful because there is a limit to how small one can draw with a compass. Oval templates differ, some featuring more ‘pointed’ or thin ovals and some more ‘fat’ or rounded like this one. Most are made from translucent plastic, but there is quite a wide variety in hardness, finish and price! Generally the harder, more rigid plastic type is more durable, but not necessarily the most finished or accurate. Often the transparent, tinted acrylic ones (as below) seem to be the better quality, i.e. from the German firm Rumold.

When using the circle template, unless drawing freehand it’s important to define the centre of the circle you want first and draw up a cross from this so that you can position the template exactly over it i.e. with cross positions aligning. To draw the circle you should click just a little extra length of pencil lead out, so that only the thin lead is touching the template and the pencil needs to be kept as vertical as possible while drawing because otherwise the circle will distort.

Especially if you use these a lot and rely on them, it’s very important to care for them. The plastic can be easily scratched or dented and this is obviously not wanted on the inside edge of the shapes. They certainly can’t be used for cutting against without damaging them, no matter how careful you might try to be!

Where to get and what they cost

There’s a wide variety of these so the following is just an indication of price and where to look. It’s better to buy these where you can look at what you’re getting. Because I can’t find the brands anymore of the ones I’ve got I can’t vouch for quality.

amazon.co.uk £2.59 ‘8.7″x5.2″ Educational Stationary Template Oval Ruler Guide Clear Green’ fat ovals from 4-42mm long with ‘crosshairs’ marked, green translucent; £1.85 ‘Helix Circle Stencil Template -30 Circles’ from 3-28mm diameter. This is the softer, flexible polypropylene version. Not as durable but suitable for direct stencilling, can be washed carefully afterwards.

greatart.co.uk £3.95 ‘Rumold Duo Circle Stencils’ durable transparent yellow acrylic. Circles from 1-35mm diameter.

Specially-made templates

Sometimes it’s necessary to create a drawing template when repeated forms are needed. I posted an example of this recently in an article about making simple architectural models in corrugated cardboard. One technique when building with this material is to create repeated flat shapes which slot into each other to form 3D constructs. Below is a simple one, involving the repetition of a horizontal shape held together with repeated vertical shapes. Each has to be identical, especially re. the positions of the slots and the best way to achieve this is to cut a template first which can be traced round on the cardboard.

I cut the templates, shown in white, out of 1mm Palight foamed Pvc because this material cuts easily and the shape will last. When sizing the template I tried to compensate for the slight increase when outlining with a pencil. This meant for example that the slots in the template had to be made a touch wider.

French curves

The most regular type of curve is one which follows the circumference of a circle, having a fixed central point, and which can therefore be easily created just by using a compass. But design would be severely limited if it were confined to these. For example the curve of a spiral broadens as it progresses outwards and has no common centre. The curve of an oval or ellipse tightens at either end. Both of these forms, the spiral and the ellipse, have a pleasing regularity and their curves can be mathematically plotted if need be. But French curves are designed to take such laborious plotting out from the creation of these less ‘regular’ curves.  These tools will be familiar to most as curvy, clear plastic shapes which look like elements from a rococo pattern book. There is a standard core of three different shapes .. usually these are the only ones on offer in art shops .. which also differ a little in size, and the theory is that any curve or combination of curves can be composed with their help.

I’ve read the suggestion a number of times that being able to plot or compose curves in a digital drawing programme is making drawing tools such as these redundant. It seems to be assumed that all computer drawing techniques are bound to be easier and, typically, it misses a great deal of the point! Yes, the computer can be invaluable as a tool if .. in this case .. the outcome is known, i.e. a particular curve to fit in a particular space. But the great advantage of French curves .. and yes, working with real, physical pencil and paper! .. is that they can be used so freely and so quickly to compose with! For example I used French curves to develop the template shapes below .. wild variations on a rococo chair leg for some furniture ideas. It was so easy and quick to mess about .. to test different combinations of parts of the French curves in pencil .. before arriving at ones that looked promising!

I was, however, dissatisfied with being limited by the ‘scale’ of the French curves available so I made smaller versions by reducing their outlines on the copier by 75% and 50% and cutting these shapes very carefully in Pvc. This has provided greater freedom but the disadvantage is that these are opaque, so at times it’s difficult to judge what shape is being created because part of it may be hidden while drawing. Unfortunately there’s no transparent sheet plastic I know of that can be cut as smoothly and effortlessly by hand as the foamed Pvc.

Where to get and what they cost

greatart.co.uk £3.95 ‘Rumold Set of 3 French Curves’ transparent acrylic

Compasses

It is usually essential to have at least one ‘pair of compasses’ to make regular circles. As I’ve said, very small circles i.e. 20mm diameter or less, may be easier to achieve with a circle stencil or template (see above).

But the small compass shown here at the bottom and in close-up below is a common type specially designed for small circles, although one would need practise to create a steady one less than 15mm diameter. It’s arms are fixed, but can be narrowed or widened by turning the adjustment wheel. These compasses usually take a thick lead which needs to be continually sharpened to give a clear, sharp line. The best way of doing this is with a nail-file. The more standard size and type of compass shown above it usually takes the same kind of thick lead, but I’ve modified both of these.

In one I’ve substituted the lead holder for another metal point. Art or graphics shops often sell these parts as spares. The advantage of this is that a score-line can be inscribed with it instead of a pencil line and this is often enough to provide a guiding line for the scalpel blade (I write more about this and other tools to help with cutting circles in the next part on Cutting). For the other one I’ve fixed up a special type of mechanical pencil available from Rotring, which gives a thinner, consistent line with no need for sharpening. A special attachment ring is needed, which fits most compasses, and the threading on the ring is designed to take Rotring pens. I suspect though that these pencil attachments are not as available now as they used to be.

This pencil and attachment ring originally came with the bar compass, sometimes called ‘beam compass’ shown at the top of the photo. These are designed for drawing large circles, beyond the reach of standard compasses. They consist of an aluminium bar with two sliding attachments which carry the compass point and the lead holder, both of which can be fixed in position. Often the ‘kit’ comprises of two lengths of bar which can be joined in the middle to extend the reach even more. There are extension bar attachments often sold with the regular form of compass which can work well if they’re secure enough, but their reach is usually only up to a radius of 250mm (500mm diameter).

Where to get and what they cost

The quality of compasses is all in the machining of the joints, the cheaper ones possibly becoming looser in time and this is not something that one can check online. Aristo is quite a good inexpensive brand, while Staedtler and Rotring are trusted but pricier ones. The following serves as a rough price guide.

London Graphic Centre £4.10 ‘Aristo School Compass’ regular type, max. reach 400mm diameter, spare leads; £19.95 ‘Aristo Compass 7 Piece Set’ includes small and regular compass sizes and extension rod; £39.54 ‘Ecobra Beam Complete Compass 50cm’ with pencil, pen and needle attachments (the simpler kind, not the Rotring type shown above). Reach up to 980mm diameter.

Other geometry tools

Here below I am using a protractor to mark out how the steps of a spiral staircase radiate from the centre. One mistake I sometimes used to make with the protractor was placing the flat bottom edge of the plastic against the intended point of origin of the angle when it should be the centre of the small semi-circle above it.

Although one might assume that one protractor must be pretty much the same as another, there are some differences in the detailing. I prefer the example below which makes it easy to read from ‘0’ upwards either side .. not all are like that!

One addition I have had to make though is a few reduced size versions on the copier. Sometimes if an angle needs to be marked on a piece of work smaller than the protractor, there’s nowhere to mark on so I’ve found it helpful at times to have these smaller versions which I’ve spraymounted on Pvc.

Weighing and dosing

Below is a relatively inexpensive digital kitchen scale for weighing amounts up to 5kg. For most work I’d recommend getting one which displays in increments of 1g i.e. sensitive to small amounts, so that it’s possible to mix very small amounts of resin and even record the recipes of small colour tests. The type shown below is a particularly unfussy and good-looking one from ADE Germany who seem to specialise in scales with flat safety-glass coverings. Although this weighing scale cost more than average the simple surface and cleanable glass is a bonus against spillages of resin. These scales usually take two of the small 1.5V AAA batteries and these don’t often need to be changed.

A common function with these scales is that if you place a cup on the scale first and then press ‘on’ it will start reading from ‘0’ without the weight of the cup. Sometimes though, I prefer to include the weight of the cup to prevent any confusion if the scale times out, which it will do if there is no activity for a few minutes.

Where to get and what they cost

They commonly measure around 16cm across and between 18-23cm in length. They can be set to either Imperial or metric measurements.

Argos £19.99 ‘Salter Glass Digital Kitchen Scale’ complete glass covering, black, touch sensor, max 5kg, graduations of 1g; £14.99 ‘Salter Stainless Steel Kitchen Scale’ circular steel weighing area flush with surface, push-button, max 5kg, graduations of 1g

Disposable plastic pipettes like these below can sometimes be found singly in craft shops, but here you may be paying far too much for them. I get these online from www.e-deala.co.uk either 1ml pipettes ( i.e. holding up to 1ml of liquid) £8.99 for 100 or 3ml pipettes £12.99 for 500. I find them most useful for dosing out very small volumes of resin and for dosing catalyst when mixing silicone rubber. They also help if you want to dose very small amounts of paint to record colour mixes by volume. Although ‘disposable’, they can be used repeatedly if they can be rinsed out straight after use.