Photo: GraphGrid frame with rubber bands per two centimetres and two crossing axes placed on the TactiPad.
Although the main application for the GraphGrid is often a regular rectangular grid, there are other applications in which one or more rubber bands can be placed diagonally, in addition to the regular horizontal and vertical axes.
3D coordinate system
By adding a third axis which passes through the intersection of the other two axes (the origin) at an angle between 30 and 45 degrees a 3D coordinate system occurs. In here you can create drawings of three-dimensional bodies.
Shape outline
You can use the rubber bands to compose the outlines of 3D bodies as well, such as a cube or pyramid. Again, you can distinguish between different (visible or invisible) line segments with higher and lower running rubber bands. The indents at all four outsides of the GraphGrid allow you to position the rubber bands at any position and angle.
Photo: Parabola tool on TactiPad ; X to the power of 2 / (X)^2.
Detailed description
The inner space of this U-shaped tool is a parabola. It has the contour of the function X to the power of two. The two poles of the U have indented centimetre indications along the outside. Three medium size alignment indents are provided; one in the middle of the bottom side and one in each of the two poles. Pushpin markers are provided in the top surface of the tool. The contour of the graph goes down and up again. At the two ends of the contour pen blockers are provided. Indented positions along the curve reflect Y values for X equals -2, -1, -0,5, 0, 0,5, 1 and 2.
Photo: A parabola has been drawn at X=0 and Y=0. The tool is positioned to create a second one at X-3 and Y=2.the ruler serves for the alignment.
Steps
Draw an X and Y axis with the ruler. Align the bottom indent with the Y axis and the ones in the poles with the X axis. Draw along the inner contour of the tool.
Lowest value for Y. You may choose any other coordinate as the minimum for the y value. The centimetre indications help to align the tool with the axes or the ruler.
The hyperbole represents the function 1 divided by X (1/x). The tool is L-shaped. Both parts of the L have a length of 10 centimetres. The inner corner of the tool is curved. By nature of the formula, the tails of the tool become very thin. To maintain the sturdiness of the tool, additional material has been added. For alignment purposes, a small square is left out at the lower left corner of the tool (X=0 and Y=0). As well as near the endings of the curve a flat section is provided. The graph contour endings are equipped with a pen blocker. Pushpin markers are provided at the top surface.
The formula represented in this tool is a smooth curve only going down, seen fromm X equals 0 to X equals 8. Along the curve small indents are provided to indicate Y values corresponding with X values equal 0,25, 0,50, 1, 2, 3, 4, 5, 6, 7 and 8 respectively.
For convenience place a pushpin in the crossing of the X and Y axis. When positioning the tool, be aware, the additional material covers the X and Y axis. Therefore, align the tool with the two axis by placing the flat sections at the tails with the axis. Draw along the contour of the tool. Rotate the tool 180 degrees clockwise. Align the tool with the axes and draw the second part of the graph.
The SinTang tool combines graphs for three functions; the sin(X), the cos(X) and the tan(X). More precise, a half period of the sine graph and a quarter of the tangent graph. The sine graph, is the ‘hill’ contour which is the first half period of the sine graph. The cosine graph is the for 90 degrees shifted to the left sine graph.
When placing the tool looking at the hill, the top side of the tool is a left to right downhill slope. After rotating 90 degrees clockwise it represents a quarter of the tangent graph. The vertical left and right hand sides have an indented centimetre indication. Pushpin markers are provided at the top surface. For sine and tangent values of 1, the distance along the Y-axis is 4 centimetres. These dimensions provide sufficient ‘tactile space’.
The range from 0 to 180 degrees X values is distributed over a length of eight centimetres (aprox. 3 inches). At 90 degrees is the top of the graph (maximum amplitude) at an height of four centimetres. Small indents are provided in the curve at 30, 45, 60, 90, 120, 135, 150 degrees positions. Pen blockers are provided at 0 and 180 degrees positions.
Detailed description of the tangent tool
The tangent part of the tool has to be rotated for 90 degrees clockwise and counter clockwise. The contour of the tangent has small indents indicating the 30, 45 and 60 degrees positions on the X axis. The tan (45) is 1, the height of the graph is 4 centimetres. Pen blockers are provided at the 0 degrees and towards the 90 degrees position. A length of four centimetres along the X axis covers a range of 90 degrees.
Draw an X axis with the ruler. Mark the X=0 and X=180 degrees positions. The distance between the two marks is eight centimetres.
Align the sides with the two centimetre indications of the tool with the X axis.
Draw the contour line for the sine from the X value of 0.
Start at the pen blocker to avoid glitches. Draw along the contour until the pen blocker at the X value of 180 degrees which is on the X axis.
Hold the pen on this position and rotate the tool around this pen position so the tool is upside down.
Continue drawing the second half of the tool until reaching the pen blocker again on the X axis.
For convenience place a pushpin at the 180 X position first and rotate the tool around the pushpin.
You can also place pushpin(s) in the pushpin marker positions to hold the tool in place.
Cosine graph
Basically the shape of the cosine has the similar shape as the sine. However the graph is shifted to the left for 90 degrees.
Draw an X axis with the ruler. Mark the 0, 90 and 180 degrees positions. A section of 90 degrees has a length of four centimetres.
Align the tool with the X axis where the right pen blocker is positioned at the 90 degrees position.
Draw along the contour starting at the top (X=0) downwards to the X axis.
Rotate the tool 180 degrees clockwise. Align the tool with the X axis and draw the negative part of the graph from 90 to 270 degrees.
Rotate the tool once again. Align the tool with the X axis and draw the last quarter of the graph up from the X axis on to the top of the graph.
Tangent graph
Draw an X axis with the ruler. Mark the 0, 90, 180, 270 and 360 degrees positions. The distance between each position is four centimetres, which covers 90 degrees.
Draw two asymptote lines: One at 90 degrees and one at 270 degrees.
The distance for the first asymptote line is four centimetres from the 0 degrees position on the X axis, the next one is at a 12 centimetres distance.
For the first section of the graph align the short (four centimetres) side with the X axis. Start at the pen blocker (0 degrees) and draw along the tangent contour upwards until you approach the first asymptote.
For the second section of the graph find the 180 degrees position (preferably provided with a pushpin).
Hook the pen blocker with the pushpin while the tangent curve is pointing down. Align the tool with X axis and draw the lower part of the graph.
For the third section rotate the tool around the pushpin 180 degrees counter clockwise. The tool has the same position as for the first section.
The fourth section is similar to the second section. Find the 360 degrees position, hook the pen blocker to the pushpin and align the tool with the X axis and draw the curve going down untill you approach the second asymptote.
Photo: Lens tool for convex, concave and mirror on the TactiPad.
Global description
The symmetrical tool could be described as a traditional house where the top part is curved. The first floor is one big window where to top side is curved. The second floor has a window where the top and bottom sides are curved in opposite directions. In the top and bottom sides of the tool small indents are provided to align the tool on the median light beam. Pushpin markers are provided at the top surface.
Your both hands and fingers are the core of the tool set to create raised line drawings. For the TactiPad, they need to be extended with additional tools such as a pen, a ruler, compass and many others. Probably they will execute new gestures and movements. So, it might well be that you / your hands and fingers can benefit from some training in order to perform the drawing tasks as best as possible. The definition of ‘best’ is open for discussion, but aspects like speed, fluency and accuracy are certainly part of this.
In this text you find instructions and exercises to become ‘better’ in free hand drawing. In the section ’measuring and drawing with a tool’ you find additional information to develop various drawing strategies. With these two sections we would like you to get to the point where you just grasp the pen and draw the subject of interest, without having to think on the ‘how to’ part.
Pen position
It is not easy to describe the ideal position on how to hold the pen in your hand. Here is an attempt, where it is assumed the pen is in your right hand. Take the pen in your right hand with the tip away from the hand. Bring the thumb, pointing finger and middle finger of your left hand loosely together so they form a triangle. Stich the pentip into this triangle for about 1,5 to 2 centimetres. Your fingers will move away from each other.
Now place your thumb and pointing finger of your right hand against the tips of the left hand fingers. As by nature , the middle finger will also go to the pen. Now the tip of the pointing finger and the area near the first joint of the thumb hold the pen whereas the middle finger presses from the side against the pen. The pen is inside the three fingers of the right hand with the pen tip pointing left. The middle finger supports the body of the pen. In fact the thumb presses the pen against the finger. This resting position can vary due to personal preference, but near to the nucle seems like a good position.
Photo: Raised line on TactiPad, with pen and finger.
Alternatively you can hold the pen in your fist, but it is harder to control the precision in your drawing because the movements come from your wrist and/or elbow.
Exercise: Drop the pen on the table and pick it up as fast as possible. Follow the above instructions to position the pen in your hand. Place the pen tip on the drawing area. Repeat the steps 50 times.
Positioning your hand on the drawing board
When the pen is in your hand you can role the hand off to the right. The right part of your wrist is now on the drawing board surface. The bone that is present here is a perfect support and turning point; the hand can swing and the fingers can move in and out. The combination of these two movements offer space for detailed drawing actions. See also basic shapes. Larger movements origin from the elbow and/or shoulder.
Exercise: Put your wrist on the drawing board and investigate which area you can cover with your hand and fingers while keeping the wrist at the same position. Use your left hand to get a feel for the distances.
Pressing on the paper; how much force
When holding the pen as described above, you can start drawing. Start somewhere near the top left corner so there is enough paper for the first exercises. Place the pen on the paper. The pen is in fact leaning over in the direction of your hand. Place your pointing finger of your left hand against the pen tip. Press down and drag the pen towards you. Your left hand pointing finger should now discover a raised line! This pulling operation is the most easiest one.
Exercise: At this point you may test a few times how much force you need to apply to get the effect. Also, a different force results in different heights.
Please note, the lines that you get are not really soft. The paper has a miniature weaver pattern that creates the raised line effect. When looking into the details, the line is not fully smooth. At first touch however it is a solid line.
Your name in large characters
When you know the shape of the characters of your name, it is funny and good exercise to write it a few times down. Make sure the characters are at least two centimetres (approx 1 inch) high or more. Writing your name forces moving the pen in different directions and simultaneously keeping an equal force to maintain the height of the lines. Now pull and push operations are alternated.
Basic shapes
Time to move on to the next exercise; creating basic shapes that you need quite often. Exercise: Lean with the side of the wrist on the drawing board and draw the shapes with a size of 2,5 centimetres (approx 1 inch). Do not move with your arm while drawing one of the following shapes:
Short line
(Equilateral) Triangle
Square
Circle
Ellipse
You will experience an increased difficulty in this list. The images may be positioned next to each other or even partly overlap.
Drawing straight lines
The definition for a line is the shortest way between two points, but how to get this right? For short lines up to 5 centimetres (approx 2 inch) this can be done while keeping the hand in the same position.
Using your finger as ruler. For a little longer line you could drag the pen alongside your finger. Just try this and you will be amazed how well this goes. Generally speaking it is recommended to keep the hand that is not holding the pen on the drawing board as well. At least when you are not using a tool.
Draw a line with a length of 10 centimetres (approx. 4 inch) between two finger tips is now possible. Find the begin and end position and place your thumb and pointing finger respectively. Determine based on your previous experience the direction on where to start the line (pulling or pushing the pen). For this distance the hand has to rotate together with the fingers that hold the pen. Use the, for you, highest speed to move the pen to keep the line straight. Lines of higher length require a tool like a ruler. However, in case they don’t need high accuracy, you can draw them with high speed, also moving your elbow.
Photo: The left hand pointing finger used as a ruler while drawing short lines with your right hand.
After having created your first raised lines, there are a few more things we would like to bring to your attention. Some are just good to keep in mind. Others will help to develop a variety of drawing strategies.
Orientation of the drawing board and horizontal/vertical lines
The word ‘orientation’ is used throughout the product descriptions and manual texts. When the drawing board lays flat on the table and the longest side goes from left to right, the drawing board is in landscape orientation. Make sure the hinge is pointing backwards.
When the shortest side is horizontal, the drawing board is in portrait orientation. The hinge should point to the left. Knowing about the subject you want to draw, will lead to the orientation of the drawing board you choose. Apart from the orientation, lines drawn on the drawing board can be in the horizontal or vertical direction. Also moving tools up/down and left/right within the drawing area are used, independent of orientation. Knowing about distances; measuring and estimation.
Photo: The distance covered with four fingers measured with the ruler.
The dimensions of the TactiPad and related products are based on measures that are commonly used. The reasoning behind is that it becomes easier to get distances ‘in your fingers’, which will make your drawing actions more efficient. It is very helpful knowing about the distance you can bridge based on the width of two, three or four of your fingers or the length of your pointing finger.
Play around with the ruler to find out how far you need to spraid your thumb and pointing finger for particular distances. Exactly measuring is best with a dedicated tool, but a good estimation is good enough in many cases.
Measuring and aligning a tool
The measurement indications along the frame of the drawing board serve as the main reference for measuring positions across the drawing area. All tools have tactile properties that match these indications. Either with the semi-circular centimetre marks along the top surface, or with small indents along the edges of the tools.
Touching the surface with the fingers and/or listening to the tick sounds that occur when tracing the pen along the indented sides, are two methods to ‘read’ distances. Where this is useful, the bodies of the tools have a width of one centimeter. So placing one tool adjacent to the other will maintain the regularly measuring system. See the detailed descriptions and manuals of the ruler and TactiForma tools.
Knob position and measuring along the drawing board frame
The unscrewed knob can be placed in an exact position by moving it against a finger that is crossing the groove while touching the measurement indication at the desired position. Keep in mind that the knob has a radius of one centimetre and the bodies of the tool have also their width. So you may have to add or deduct one centimetre to end up as where you want.
Mark a dot with pen or use pushpins
A drawing is never only one line from begin to end. Curved lines, straight lines under various angles are connected. To mark the start and end position of a line you can press with the pen on the paper. A small tactile marking will appear. This marking can serve as a point of reference. You can use a tool to create a line between.
Two markings, you want the line exactly starting and ending at these markings. That means that the ruler may not cover the markings. Initially it takes some sensivety to find them. Otherwise, you can place pushpins in the markings first. Than place the tool against the pushpins and draw the line between the two pushpins.
Tracing a pen along a tool
The tools are made of plastic and have a thicknes of aprox 3,5 milimetres. The tip of the pen has a width of 1,5 milimetres and sticks out from the body only for a short distance. At close look, the edges of the tools are rising up from the drawing area like a steap ramp. Even when the pen is in a fully upright position, the tip might not be exactly against the tool; the body of the pen prevents this.
Instead of a balpen you can use any other pointy device with a longer tip, but as we have seen before, fully upright is not the best position to hold the pen to perform the pull and push movements. When the pen is tilted off from the tool the tip can go straight along the tool. This approach works well when using pushpins. When the pen is tilted toward the tool the tip moves away from the tool, because the body ‘roles’ off of the ramp.
Photo: Pen is tilted of from the tool.
Photo: Pen is in right up position against the tool.
Photo: Pen is tilted to the tool.
You can use this effect to your benefit when working with marks on the paper. Place the tool just a short distance away from the marks so you still can find them with your fingers. You will get a feel for the tilting angle of the pen.
Drawing a straight line
Although we haven’t described the ruler or any other tool in detail up so far, here is an approach for drawing a straight line. Starting in one of the (end) points and just draw onwards to the other, may cause the pen to pass by this position. To avoid this, find one of the two positions. Draw the line from here only partly in the direction of the other end point. Now start drawing in the other point into the direction of the first. You may draw a section of the line twice, but this doesn’t matter. Pushpins in both end points will serve as pen blockers; the pen will run against the pushpin that tells you to stop drawing any further.
Lines covered by a tool
Using a tool to draw lines and shapes bring in more accuracy and speed into the drawing proces. The side effect is that the tool could cover part of the already existing lines, which makes it more difficult to find the exact begin/end positions. Therefore, it is worthwhile to look on which side of the foreseen line the tool is placed; left or right from the line.
Rotation and angles
In various manual sections you find instructions where tools are rotated over a number of degrees. The lowest / nearest side of the frame to you is the zero degrees reference. So from any position to the right, parallel to the frame is an angle of 0 degrees. Rotating counter clockwise over an angle of 90 degrees results in a vertical line. Rotating 90 degrees clockwise as well. It is indicated what the rotation point of the tool is; either the centre of the tool or a corner. In some cases you can use a pushpin as a fixed point for the rotation.
Photo: Four pushpins in the drawing board and in pushpin markers of the 45triangle.
Global description
The 10 pushpins are stored in a cushion in the carrying bag. The length is about 2 centimetres. The head of the pushpin is ball-shaped. The pin is made out of metal.
Generally speaking, the use of pushpins will increase the overall accuracy of the drawing operations. On the other hand it takes time to handle the pushpins safely and efficiently Throughout the various manual sections the use of pushpins is explained. The usage of pushpins is based on your experience and preference and also on the accuracy you can get with or without the pushpins. Overtime your drawing skills will increase.
The pushpins are stored horizontally in their cushion. Take the head between thumb and pointing finger and stick it through the drawing paper into the rubber mat. Due to the flexibility of the rubber, the pushpins can waggle, but they won’t fall out. Don’t be afraid, they do not damage the rubber.
Markings and pushpins as reference points
By pressing with the pen on the drawing paper a raised dot will appear. In many cases this is sufficient as a reference point. In addition you can place a pushpin as reference point on the desired position or in the pre-made marking. Tools can lean against the pushpins. While drawing, they serve also as pen blocker; the tip will bump into the pushpin. During measuring a distance certain points can be marked with the pen and/or equipped with a pushpin.
Pushpin markers
Many of the tools that come with the TactiPad or come as extensions, have so called pushpin markers. These are indented circles with a tiny hole in the middle at the top surface of the tools.
When one or two pushpins are stuck into the pushpin markers, the tools are fixated on the drawing board. For this approach the drawing process requires extra time, but the tools will for sure stay on their position.
Organising pushpins
You can take them one by one from the cushion. You could also use a magnet to organise them. A spare magnet can be stored in the small pocket in the carrying bag. The base of the compass is magnetic, so you can use this part to organise the pushpins.When holding the drawing board in landscape, in the middle of the left and right side and in the middle of the rear side cavities can be found. In here magnets are located that can also hold the pushpins.
Create a triangle with markings and pushpins exercise
To experience the difference: Mark three positions somewhere on the drawing area with the pen. Use the slik side of the 45 triangle to connect the positions. An irregular triangle will appear. Measure the longest side of the triangle and mark the halfway position. Place a pushpin here. Place a pushpin in the opposing corner and provide the line between the two pushpins.
The ruler’s width is 4 centimetres, and it reaches 43 centimetres long. At one end of the ruler, a 2 centimetre wide round hole is made. In the rest of the ruler there’s a 2 centimetre wide groove.
The groove has two bridges; one at 10 centimetres, the next at 20 centimetres. Indents in the groove indicate the 5 centimetre distance in between. The ruler has a measurement indication on both sides, for a length of 35 centimeters. One side has small indents along the edge at every centimetre, the other side is slik.
Photo: The ruler placed on two knobs of the drawing board.
Especially for the ruler the knobs in the frame of the drawing board come in handy. They can be placed at any position in the grooves. With just the hole on a knob, the ruler can still rotate. In case the ruler’s groove is placed over a second knob, the ruler is fixated. For an exact horizontal or vertical alignment knobs have to be in equal positions in opposing grooves. When the ruler is horizontally or vertically placed, with the hole over a knob, the zero position of the ruler is on the edge of the drawing area.
Diagonal lines
One of the two knobs in two grooves are placed at the very far end of the groove. For drawing a line at a precise position, take in account that the rulers edge is 1 centimeter wide.
The hole that fits around the knob is two centimetres wide and sits in the middle of the ruler. In other words positioning the ruler on a desired position is two centimetres higher or lower or left/right respectively, seen from the centre of the knob. Another method is to have the knobs partly unscrewed so they can move. Place the ruler on two knobs and slide the edge of the ruler to the desired position, using the measurement indications of the frame.
Photo: The ruler is positioned to draw a diagonal line on the drawing board.
Draw a (long) straight line
For many purposes it makes sense to have a horizontal and or vertical line as a start for a drawing. Whether it is the bottom line, the horizon or an axis. Find the horizontal and or vertical positions for knobs, draw the lines and remove the ruler from the knobs. For shorter lines you can use also the sides of the triangles as a ruler.
Aligning tools with the ruler
Leaving the ruler sitting on two knobs while placing other tools against the ruler’s edge, helps to add more lines/elements to the drawing. Aligning the tools of the TactiForma or the triangles that come with the TactiPad can be useful.
Photo: The 45Triangle aligned with the ruler, creating a bar chart.
X and Y axis/coordinate system example
It is assumed, the drawing board is in landscape orientation. Place the knobs in the vertical grooves at positions 9 and 11 centimetres respectively. Place the ruler over the lowest two knobs. Draw a line horizontally at 10 centimetres (the X axis) Everything above the ruler has a positive Y value.
Reposition the ruler on the two higher knobs and everything below the ruler has a negative value. Place the knobs at 14 and 16 centimetres in the horizontal grooves. Place the ruler on the knobs at 14 centimetres and draw a vertical line at 15 centimetres, the Y axis. Having the knobs in these positions and switching the ruler enable to align and measure for positive and negative values along both axes.
The compass is made out of two main parts: a beam and a base. The beam has a needle shaped turning point on one side and a pointy shape, the spike that can move along the beam. The spike produces the raised line of the circle. The needle slides into the centre of the base. The beam can move around the base in horizontal orientation clockwise and counter clockwise just above the drawing area.
Photo: The three parts of the compass lying on the drawing board; the base, the beam and the spike.
The base has a semi-circle shape with a diameter of almost 6 centimetres. If you want, you can see a rabbit face with two ribbed ears, two eyes, a mouth, a nose, and a arrowhead shaped hat, where one corner has been cut out.
In the center of the base is the nose, the hole that holds the needle/beam up right. Along the outer edge of the base, three semi-circular hollows have been made. According the face analogy; one at the bottom, the mouth and the eyes near the ears. One half of the arrowhead is cut off. At the bottom side the base has three strong magnets and five anti slip feet. With this combination the anti-slip effect is really high.
Photo: Close up of the base, two fingers holding one of the ears.
Compass beam
The beam has a total length of about 13 centimetres. Three small ramps at the top side are present to indicate the smallest radius of three centimetres. From here on indents per half centimetre can be found. The maximum radius of the circle can be set to 12 centimetres. The beam has a ring on one side that encloses the needle in a ball mount. This enables the beam to be lifted or tilted during rotation. The needle could be described as a mushroom. The ribbed head on top is sitting on a metal ball that is surrounded by the ring. The needle continues below the ball. At the end three small spikes can be found.
Spike
A ribbed, open block can move along the beam. It will click into the indents so it stays in position. Underneath the block is a triangular shaped that is the actual ‘pen’ that draws on the paper.
The beam and spike are assembled together in an elastic tube. Remove the spike from the beam so you can take the beam from the tube. Re assemble the two parts. Make sure the right side of the spike is facing the needle. For now, move the spike fully over the beam towards the needle. The compass base is stored separately. It is hold in place with two elastic bands over the ears. Fetch the band and enlarge the opening to take out the ears one by one.
Photo: Compass beam stored in the carrying bag.
Magnetic force
The base has strong magnets so it adhesives to the metal plate underneath the rubber mat of the drawing board. When placing the base on the drawing board you will experience the magnetic effect right away. The base will slide not very easy.
Removing the base from the drawing board becomes easy when lifting the base at one ear. Be aware, it can attach itself to other metal objects whenever the distance is small enough.
Adjusting the radius
Before assembling the compass, play around with setting the radius to particular values. Therefore, hold the needle’s side of the beam in one hand and take the ribbed spike between thumb and pointing finger and move it in steps to the desired position. You will recognise the clicks while moving. Check the radius by counting along the beam, starting at the three centimetre starting block indicated with three small ramps on the beam.
Draw your first circle
Set the radius for the circle at six centimetres. Choose a position for the base somewhere in the middle of the drawing board. Put the needle in the centre of the base. The spike will rest on the drawing paper.
Lift the beam while rotating so it is pointing away from you. Place the pointing finger of the left hand on the needle’s head and hold it steady. The thumb and middle finger can hold the base. Take the spike between your thumb and pointing finger of the right hand. By nature the beam / spike will tilt towards you when you drag the pointer towards you while pressing down as well. Remember the pull operation for smooth drawing.
Photo: The compass is placed on the drawing board. The needle is supported with a pointing finger and the spike is held between thumb and pointing finger of the other hand.
The contour of the circle will rise up behind the spike. While dragging / rotating the beam with spike, at some point you will run against the hand that keeps the needle in place. Now take your hands off and let the compass sit on its position. You can change hands now; the pointing finger of the right hand will now support the spike. The left hand will take over. The draw operation by continuing to the point where you started drawing. The magnets in the base ensure the base will stay on its position. It doesn’t matter if you re draw part of the circle.
Indication for the centre of the circle
The bottom end of the needle has three very small spikes. When you press and turn the head on top, without moving the whole beam, a small tactile circle is created, indicating the centre of the circle drawn. Placing the compass base on a particular position. The arrowhead can be used to precisely place the centre of a circle on a specific point in the drawing.
Mark this position with the pen or place a pushpin. Move the centre hole to the mark and align with the sides of the arrow head. If you place the corners of the arrowhead on two crossing lines, the compass needle is exactly on the crossing.
Photo: The compass base with the centre on crossing lines.
The alignment indents around the outside of the base can be used to precisely position the centre of the circle on a line. Check with the fingertip if the middle of the two eyes are on the line. The centre is already on the line. Check if the middle of the mouth is also on the crossing line. The centre is now on the crossing.
Fantasy – clock
Draw a circle with a radius of six centimetres. Draw a second circle with a radius of 7,5 centimetres with the exact same centre position. Start with the smaller of the two circles. Leave the base sitting on its position. For the larger one take the base between your finger tips and press it down so when you pull the spike to its next position, it does not move. Draw the circle and check if the distance comes out equally all along. Provide the space between the two circles with small lines by freehand as indicators for the hour positions.
We use cookies to ensure that we give you the best experience on our website. If you continue to use this site we will assume that you are happy with it.Ok
