Bad Weather Mount Tester

When you buy a new telescope mount, the first things to do is to measure the periodic error, because if the periodic error is really high, you would like to complain and send it back as fast as possible. Unfortunately, most of the time there will be bad weather after buying astro gear for an indefinite amount of time.

Bad Weather Mount Tester to the rescue!

Using this program you can test the periodic error of your mount any time, any place, provided you have a spare computer and monitor and a little bit of space.

Documentation

The full user manual is available at https://jscheidtmann.github.io/BadWeatherMountTester/.

How to Install

From PyPI (all platforms)

Using pip:

pip install BadWeatherMountTester

Or using pipx for an isolated install:

pipx install BadWeatherMountTester

Then run the application:

bwmt

From GitHub Releases (pre-built binaries)

Download the latest release from the GitHub Releases page.

• Linux: Download the .tar.gz archive, extract it, and run ./bwmt
• Windows: Download the .zip archive, extract it, and run bwmt.exe
• macOS: Download the .tar.gz archive, extract it, and run ./bwmt

From Source

git clone https://github.com/jscheidtmann/BadWeatherMountTester.git
cd BadWeatherMountTester

Install uv if you don't have it, then:

uv sync
uv run bwmt

How to Contribute

1. Fork the repository and clone your fork

2. Install development dependencies:

   uv sync --dev
   

3. Install just for common development tasks:

   Platform	Command
   Windows	winget install Casey.Just
   macOS	brew install just
   Linux / Raspberry Pi	curl --proto '=https' --tlsv1.2 -sSf https://just.systems/install.sh | bash -s -- --to ~/.local/bin

4. List all available recipes:

   just
   

   Key recipes:

   Recipe	Description
   just test	Run the test suite
   just lint	Run ruff and flake8
   just translations	Extract strings, update .po files, compile .mo files
   just compile-translations	Compile .po → .mo only
   just run	Run the application

5. Internationalization: The project supports German, English, and French via Flask-Babel. Translation files live in src/badweathermounttester/translations/. After editing .po files run just compile-translations.

6. Submit a pull request against main

CHANGELOG.md

This project keeps a CHANGELOG.

Credit

This software is based on the idea by Klaus Weyer from Solingen, Germany. Rest in Peace, Klaus!

Author, Copyright & License

Copyright (c) 2026 Jens Scheidtmann and contributors (see CONTRIBUTORS.md)

This file is part of BWMT, the Bad Weather Mount Tester.

BWMT is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

BWMT is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with BWMT. If not, see http://www.gnu.org/licenses/.