I want to draw this picture with (normal) TikZ:
How do I have to draw the "vertical arcs"?
MWE:
\documentclass[border=5mm]{standalone}
\usepackage{tikz}
\usetikzlibrary{backgrounds}
\begin{document}
\begin{tikzpicture}[
background grid/.style={help lines, draw, step=5mm},
gridded,
every path/.style={very thin},
]
\coordinatelabel= at (0,0);
\def\Radius{2}
%\shade[ball color = white] (M) circle[radius=\Radius];
\draw (M) circle[radius=\Radius];
\def\R{2}
\foreach \v in {-6,...,6}{%%
\pgfmathsetmacro\h{\v\R/6}
\pgfmathsetmacro\Radius{sqrt(\R^2-abs(\h)^2)}
% Horicontals ================
% front
\def\StartAng{0}
\def\EndAng{-180}
\draw[] ([shift={(\StartAng:\Radius)}]0,\h) arc[start angle=\StartAng, end angle=\EndAng, x radius=\Radius, y radius=0.25\Radius];
% back
\def\StartAng{0}
\def\EndAng{180}
\draw[help lines] ([shift={(\StartAng:\Radius)}]0,\h) arc[start angle=\StartAng, end angle=\EndAng, x radius=\Radius, y radius=0.25*\Radius];
% Verticals ================
% front
\def\StartAng{0}
\def\EndAng{-180}
\draw[blue] ([shift={(\StartAng:\Radius)}]\h,0) arc[start angle=\StartAng, end angle=\EndAng, y radius=\Radius, x radius=0.25\Radius];
% back
%\def\StartAng{0}
%\def\EndAng{180}
%\draw[blue,densely dashed] ([shift={(\StartAng:\Radius)}]\h,0) arc[start angle=\StartAng, end angle=\EndAng, y radius=\Radius, x radius=0.25\Radius];
}%%
%\fill[fill=black] (M) circle (1pt);
%\draw[dashed] (M) -- node[above]{$r$} (\Radius,0);
\end{tikzpicture}
\end{document}



