# drawing figure to scale

I have a technical drawing of a mechanical setup which I would like to draw in either TikZ or PSTricks. My experience with these two packages is very limited.

A "MWE" of the drawing is shown in the following, all units are in meters. I would like to make a drawing which is true to the various scales. I think one way to achieve this is simply to use coordinates to label the various positions and lengths, but I am very interested in reading your comments.

My questions are:

1. Is this even possible?
2. Which package would be best for this purpose? And what strategy can I use to achieve this?
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Adapt the following code. It is very easy and basic.

\documentclass[pstricks,border=12pt]{standalone}% set border=0pt at the final stage
\usepackage{pst-node}
\psset
{
dimen=middle,
offset=.2,
arrows=|*-|*,
unit=2cm,% set it to 100cm if you want 1 scale = 100cm = 1m
}

\usepackage{siunitx}
\begin{document}
\begin{pspicture}[showgrid=false](5,1.25)% set showgrid=false at the final stage
\psframe(1,1)
\psframe(1,.25)(4,.75)
\pscircle(4.5,.5){.5}
\pcline(0,1)(1,1)\naput{\SI{1}{\m}}
\pcline[offset=0]{<->}(4,.5)(4.5,.5)\naput{\SI{0.5}{\m}}
\end{pspicture}
\end{document}


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Is it possible to add an offset such that the $x$-axis runs from (e.g.) -2..5? –  BillyJean Oct 5 '13 at 19:00
@BillyJean: Yes. It is possible by changing the pspicture domain, for example, \begin{pspicture}(-2.5,0)(5,1.25) instead of \begin{pspicture}(5,1.25). –  stalking is prohibited Oct 5 '13 at 19:08

With TikZ

\documentclass[]{article}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}[scale=2]
\draw (0,0) rectangle (1,1) node at (0.5,0.9) {1} node at (0.1,0.5) {1};
\draw (1,0.25) rectangle (4,0.75) node at (1.2,0.5) {0.5} node at (2.5,0.9){3};
\draw (5,0.5) circle (1);
\draw[<->] (4,0.5)--(5,0.5) node at (4.5,0.6){1m};
\end{document}


The result

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