The Original Spirograph CLC03111 Design Set,18 x 1 x 13 centimeters

Product Information

Shaped wheels: Shaped wheels come in a wide variety of shapes, including bar, quad, triangle, and oval. Like the round wheels, shaped versions also have multiple holes to vary the design. Parameter R {\displaystyle R} is a scaling parameter and does not affect the structure of the Spirograph. Different values of R {\displaystyle R} would yield similar Spirograph drawings. or purse and store everything you need, though you’d need to replace the paper often. These are by far the most portable sets, but even large Spirograph sets are designed with portability in mind. They come with a carrying case in which to store wheels, pens, and paper so you can make art anywhere. Spirograph set features Spirograph sets come with at least one pen; some sets include two or three. By using the pens included with the set, you’re assured that they will fit in the wheel holes. However, you can use any pen or pencil that fits in the wheel hole, whether it came with the set or not. To create designs, wheels are placed either within or along the outside of the plate or ring. Plates and rings have teeth on the outside and inside edge. Consequently, wheels can be used on either side. Plates and rings are held in place using Spiro-putty, magnets, or pins.

x = x c + x ′ = ( R − r ) cos ⁡ t + ρ cos ⁡ t ′ , y = y c + y ′ = ( R − r ) sin ⁡ t + ρ sin ⁡ t ′ , {\displaystyle {\begin{aligned}x&=x_{c}+x'=(R-r)\cos t+\rho \cos t',\\y&=y_{c}+y'=(R-r)\sin t+\rho \sin t',\\\end{aligned}}} x ′ = ρ cos ⁡ t ′ , y ′ = ρ sin ⁡ t ′ . {\displaystyle {\begin{aligned}x'&=\rho \cos t',\\y'&=\rho \sin t'.\end{aligned}}}The parameter 0 ≤ l ≤ 1 {\displaystyle 0\leq l\leq 1} represents how far the point A {\displaystyle A} is located from the center of C i {\displaystyle C_{i}} . At the same time, 0 ≤ k ≤ 1 {\displaystyle 0\leq k\leq 1} represents how big the inner circle C i {\displaystyle C_{i}} is with respect to the outer one C o {\displaystyle C_{o}} . Now, use the relation between t {\displaystyle t} and t ′ {\displaystyle t'} as derived above to obtain equations describing the trajectory of point A {\displaystyle A} in terms of a single parameter t {\displaystyle t} : The other extreme case k = 1 {\displaystyle k=1} corresponds to the inner circle C i {\displaystyle C_{i}} 's radius r {\displaystyle r} matching the radius R {\displaystyle R} of the outer circle C o {\displaystyle C_{o}} , i.e. r = R {\displaystyle r=R} . In this case the trajectory is a single point. Intuitively, C i {\displaystyle C_{i}} is too large to roll inside the same-sized C o {\displaystyle C_{o}} without slipping. A wheel must be placed inside a stationary plate or ring for designs to be drawn. Each plate needs to be held in place with Spiro-putty, magnets, or pins. Sets come with one of these three options (except for travel sets, which have a plate built into the lid).

It is convenient to represent the equation above in terms of the radius R {\displaystyle R} of C o {\displaystyle C_{o}} and dimensionless x c = ( R − r ) cos ⁡ t , y c = ( R − r ) sin ⁡ t . {\displaystyle {\begin{aligned}x_{c}&=(R-r)\cos t,\\y_{c}&=(R-r)\sin t.\end{aligned}}} Now define the new (relative) system of coordinates ( X ′ , Y ′ ) {\displaystyle (X',Y')} with its origin at the center of C i {\displaystyle C_{i}} and its axes parallel to X {\displaystyle X} and Y {\displaystyle Y} . Let the parameter t {\displaystyle t} be the angle by which the tangent point T {\displaystyle T} rotates on C o {\displaystyle C_{o}} , and t ′ {\displaystyle t'} be the angle by which C i {\displaystyle C_{i}} rotates (i.e. by which B {\displaystyle B} travels) in the relative system of coordinates. Because there is no slipping, the distances traveled by B {\displaystyle B} and T {\displaystyle T} along their respective circles must be the same, thereforeBeginners often slip the gears, especially when using the holes near the edge of the larger wheels, resulting in broken or irregular lines. Experienced users may learn to move several pieces in relation to each other (say, the triangle around the ring, with a circle "climbing" from the ring onto the triangle). Let ( x c , y c ) {\displaystyle (x_{c},y_{c})} be the coordinates of the center of C i {\displaystyle C_{i}} in the absolute system of coordinates. Then R − r {\displaystyle R-r} represents the radius of the trajectory of the center of C i {\displaystyle C_{i}} , which (again in the absolute system) undergoes circular motion thus: Round wheels: These basic wheels are probably the type with which you are familiar. They may have five to 35 holes. Each hole will create a slightly different pattern using the same wheel.