Slide-Rule

This Python 3 application helps generate complete slide rule patterns.

This is via:

• Javier Lopez: Slide Rule for the Modern Day
• Instructables: A Vintage Calculator for the Modern Day

Running

To run the program, you can download the one file as:

• Download SlideRule.py
• Install PIL via:

python3 -m pip install Pillow

• Install TOML via:

python3 -m pip install toml

Or clone this git repository locally and install per the requirements file as:

python3 -m pip install -r requirements.txt

An installation of two fonts: cmuntt.ttf and cmunit.ttf (part of the infamous LaTeX fonts)

• These can be found at: https://www.freebestfonts.com/computer-modern-font
• Install all of them if you want different typesetting options.

usage: SlideRule.py [-h] [--mode {render,diagnostic,stickerprint}]
                    [--model {Demo,MannheimOriginal,Ruler,MannheimWithRuler,Aristo868,Aristo965,PickettN515T,FaberCastell283,FaberCastell283N,Graphoplex621,Hemmi153,UltraLog}]
                    [--suffix SUFFIX] [--test] [--cutoffs] [--debug]

optional arguments:
  -h, --help            show this help message and exit
  --mode {render,diagnostic,stickerprint}
                        What to render
  --model {Demo,MannheimOriginal,Ruler,MannheimWithRuler,Aristo868,Aristo965,PickettN515T,FaberCastell283,FaberCastell283N,Graphoplex621,Hemmi153,UltraLog}
                        Which sliderule model
  --suffix SUFFIX       Output filename suffix for variations
  --test                Output filename for test comparisons
  --cutoffs             Render the metal cutoffs
  --debug               Render debug indications (corners and bounding boxes)

The program has 3 rendering modes for any of the slide rule models defined:

• render: Prints a rendering of the full size scales in their correct positions
• diagnostic: Prints a rendering containing each available scale arranged in rows
• stickerprint: Prints an image which can be scaled to 677.33 ppi in Gimp and then Print+Cut in Silhouette Studio

There are multiple slide rule models available, mostly defined in TOML:

• Demo is the original slide rule made for instruction.
• MannheimOriginal is the simplest model, with just 4 scales along the edges.
• Ruler and MannheimWithRuler show the ruler scales, which can be set along the edge of a slide rule.
• PickettN515T is made for electronics engineering calculations.
• Aristo868 and Graphoplex621 are European slide rules with a moderate number of compact scales.
• FaberCastell283 and FaberCastell283N have the large number of scales.

The produced images are also saved. The images in examples are refreshed by generate_example_outputs.py, a wrapper script you can run on new models, or to check for changes after making source code updates.

Troubleshooting

• If you have trouble finding them, look in the location where your program is (that seemed to work for me)
• render and diagnostic modes takes around 2 seconds to run, but the stickerprint mode usually takes 3 seconds to run.
• If you run across issues, comment on Javier Lopez Instructables article or here, and I will attempt to explain myself.

To understand changes, the imgdiff tool can highlight differences in image outputs (ignoring color changes with -t 0.6):

imgdiff -t 0.6 <original_image>.png <updated_image>.png <original_image>.diff.png

The included Excel file can help convert between pixels, inches, and millimeters when the slide rule is being built out of physical material.

Enjoy!