TikZ, representing pendulum

Question

I am having some problems in concluding a picture. This is my code:

\documentclass[border={10pt}]{standalone}
\usepackage{tikz}
\usetikzlibrary{patterns}

\begin{document}

 \begin{tikzpicture}[thick,>=latex,->]

    \begin{scope}
    \clip(-5,2) rectangle (5,-5);
    \filldraw[white] (-4.3,4.3) rectangle (4.3,0);
    \draw[double distance=1.6mm] (0,0) -- (3,-3) node[midway,xshift=4mm,yshift=2mm]{};
    \draw[double distance=1.6mm,dashed] (0,0) -- (0,-4.24) node[midway,xshift=4mm,yshift=2mm]{};
    \draw[draw=black,fill=white,dashed] (0,-4.24) circle circle (.3cm);
    \draw[double distance=1.6mm,dashed] (0,0) -- (-3,-3) node[midway,xshift=4mm,yshift=2mm]{};
    \draw[draw=black,fill=white,dashed] (-3,-3) circle circle (.3cm);
    \draw[fill=white] (-1.2,1.0) -- (-.5,0) arc(180:360:0.5) -- (1.2,1.0) -- cycle;
    \draw[draw=black,fill=white] (0, 0) circle circle (.3cm);
    \draw[draw=black,fill=white] (3,-3) circle circle (.3cm);
    \draw[pattern=north east lines] (-1.4,1.3) rectangle (1.4,1);
    \node at (.3,-.8) {$\theta_{d}$};   
    \end{scope}

\end{tikzpicture}

\end{document}

I get this result:

But I want to have something like this:

And I want to remove the horizontal grey lines from the linear part of the two "dashed" pendulum. Can you help me?

Answer 1

Here is my solution. I made some coordinates for left, middle and right. Also I've removed some unused code.

The thin horizontal grey lines may be a viewer problem.

\documentclass[border={10pt}]{standalone}
\usepackage{tikz}
\usetikzlibrary{patterns,calc,intersections}

\begin{document}

\begin{tikzpicture}[thick,>=latex]

    \begin{scope}
        \coordinate (l) at (-3,-3);
        \coordinate (m) at (0,-4.24);
        \coordinate (r) at (3,-3);

        % left
        \draw[double distance=1.6mm,dashed] (0,0) -- (l);
        \draw[draw=black,fill=white,dashed] (l) circle (.3cm);
        \draw let \p1=(l) in (\x1,-5) node {left};

        % middle
        \draw[double distance=1.6mm,dashed] (0,0) -- (m);
        \draw[draw=black,fill=white,dashed] (m) circle (.3cm);
        \draw let \p1=(m) in (\x1,-5) node {middle};

        % right
        \draw[double distance=1.6mm] (0,0) -- (r);
        \draw[draw=black,fill=white] (r) circle (.3cm);
        \draw let \p1=(r) in (\x1,-5) node {right};

        \draw[dashed,->] (l) to [bend right=45] (r);
        \draw[->] ($(m)!0.5!(0,0)$) to [bend right=22.5] ($(r)!0.5!(0,0)$);

        \draw[fill=white] (-1.2,1.0) -- (-.5,0) arc(180:360:0.5) -- (1.2,1.0) -- cycle;
        \draw[draw=black,fill=white] (0, 0) circle (.3cm);
        \draw[pattern=north east lines] (-1.4,1.3) rectangle (1.4,1);
        \node at (.3,-.8) {$\theta_{d}$};   
    \end{scope}

\end{tikzpicture}

\end{document}