Partner in product development

With Vink System Design & Analysis I (Jaap Vink) offer engineering services to companies.  Specialized in precision mechanics, I am an experienced and result-oriented partner in the development of complex opto-mechanical and mechatronic systems where high accuracy is required.

To perform regular or special mechanical calculations and analyses, I have developed a toolkit of software programs and a spreadsheet. You can download and use it.

Engineering Toolkit Vink SD&A for Mechanical Calculations

Spreadsheet Tolerance analysis

TolStackUp is a tolerance analysis spreadsheet (template) created in Microsoft Excel. It is designed to analyze and manage the effects of dimensional deviations of parts in an assembly.

Calculate Beam Deflection Pro

FlexBeam Pro is an easy-to-use beam deflection and buckling calculator. After entering the data, FlexBeam Pro performs all necessary calculations.

Calculate Beam Deflection Lite

Do you want to try FlexBeam first or do you not need the more extended functionality of FlexBeam Pro? Then download the free FlexBeam Lite version.

Calculate Hertz Contacts

With HertzWin you can quickly calculate point and line contacts. This handy, free program automatically performs all Hertzian contact calculations.


I’m using FlexBeam to support my classes as a mechanical design teacher at a Technical School – Javier, Spain

I have downloaded your program and have confirmed that your Hertz Contact Stress calculation matches what I have been using. I believe that HertzWin will be helpful in quickly checking my hand calculations – Michael, USA (Pennsylvania)

I can only be positive about FlexBeam, very practical! – Philippe, Belgium

I have been a user of your FlexHinge software for the past few years and have found it very useful – Joey, USA

We have tested FlexBeam Pro and are very happy with it – Jaap, The Netherlands

I would like to thank you for your program HerzWin. It is really easy to use it and it has really nice visualization – Frantisek, Czech Republic

Recent Posts

Tolerance Analysis With TolStackUp of a Construction

The article 'Setting up the tolerance chain step-by-step', described how to set up a tolerance chain step-by-step using an example. The article ended with a sketch of the tolerance chain. You can see this chain in the figure below. By processing the part dimensions...

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Step-by-Step Example of Tolerance Analysis

A previous article described the entire step-by-step plan for building a tolerance chain. It was described using a relatively simple example. In practice, however, designs can be much more complex. And then the tolerance analysis of such a design is much more...

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Stresses, Tribology and Contact Mechanics

When two objects come into contact, depending on the shape of the surfaces, there may be point or line contact. The contact force causes deformation and thus stresses in the material. If these material stresses are high, the material may fail. The material stresses in...

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Setting up the tolerance chain step-by-step

The article 'Step Plan Tolerance Analysis', briefly summarizes the steps to achieving a good tolerance analysis. The following articles discuss the method of adding tolerances. Much attention has been paid to the Statistics of Dimensional Variations of manufactured...

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Rolling Contact Fatigue

Up to and including HertzWin 3.2.0, all calculated results are for a static situation. The most important material stresses for a static situation are the maximum shear stress and the von Mises equivalent stress. The Von Mises equivalent stress is most often used to...

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Tangential Force Acting on a Hertzian Contact in HertzWin

With the program HertzWin you can calculate Hertz point and line contacts. The influence of a tangential force can also be calculated. HertzWin is available online for free since March 2009. No approximation but the exact solution In older releases of HertzWin (before...

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Refined, Advanced Tolerance Analysis

In previous articles about tolerance analysis, I discussed the step-by-step plan and how to add up tolerances. The sum of tolerances can be a worst-case sum or a statistical sum. In 'The Distribution of Tolerances' I also discussed the types of distributions that can...

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The Distribution of Tolerances

A previous article discussed statistical tolerance stack-up analysis. It is usually more profitable to perform a statistical tolerance stack-up analysis instead of a worst-case analysis. A worst-case analysis often leads to low tolerance specifications and therefore...

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Statistical Tolerance Stack-up Analysis

In the Worst-case Tolerance Stack-up Analysis article, you will read about worst-case or linear stack-up analysis. Such an analysis assumes that all dimensions in the tolerance chain have worst-case deviations from their nominal values. A statistical tolerance...

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