My name is Daniel Müller. I am a mechanical engineer and have worked as a development engineer, design engineer and project engineer in special purpose machinery; today I head the design department at a special purpose machinery company. The calculations on this site are the same ones I use and need in my own work.
It started as a collection of my own Excel spreadsheets. One file per recurring calculation, one sheet per standard, and more of them every year. What bothered me was not the effort but the uncertainty: after six months I often could no longer tell which assumption sat behind a given cell, or against which source I had checked it at the time.
That is exactly what is better here. Every calculator names its source, shows the calculation path and states the limits of application. All calculators have been verified against worked examples from the literature. What that looks like in detail is described under method and quality assurance.
The calculators are free to use in the browser. Anyone who just needs a quick calculation or wants to optimise a design should not have to create an account first. Only the export is paid: the verification PDF - the part that goes into documentation - and export files such as the cam contour for CAD import in the cam design calculator. If you would like to support the project and my work, and want full access to all export documents and verification PDFs, a subscription or a one-time purchase is welcome.
Feedback from people in mechanical engineering doing the same kind of sizing work is very welcome - it is what makes the project broader and better. Get in touch.