Partner in product development

With Vink System Design & Analysis I (Jaap Vink) provide engineering services to companies. I specialize in precision mechanics and 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 specialist mechanical calculations and analyes, I have developed a toolkit with software programs and a spreadsheet. You can download and use these.

Engineering Toolkit

Spreadsheet Tolerance analysis

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

Calculate Beam Deflection Pro

FlexBeam Pro is a user-friendly calculator for the deflection and buckling of beams. After filling in the data, FlexBeam Pro makes the necessary calculations.

Calculate Beam Deflection Lite

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

Calculate Hertz Contacts

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

Calculate Flexure Hinges

With the free FlexHinge program, you can quickly calculate the stiffness and material stress of a flexure hinge. It performs all calculations automatically.


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

Setting up the tolerance chain step-by-step

In the article 'step plan tolerance analysis', the steps to achieve a good tolerance analysis are briefly summarized. In the articles that followed, the method of adding tolerances is discussed. Much attention was paid to the statistics of dimensional variations of...

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Rolling Contact Fatigue

Up to and including release 3.2.0 of HertzWin, all calculated results related to a static situation. The most important material stresses for a static situation are the maximum shear stress and the Von Mises equivalent stress. Most commonly used to determine whether a...

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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 has been available online for free since March 2009. No approximation but the exact solution In older releases of HertzWin...

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Refined, Advanced Tolerance Analysis

In previous articles about tolerance analysis, I discussed the step-by-step plan and the way of adding up. Adding up tolerances can be a worst-case sum or a statistical sum. In 'The distribution of tolerances' I also discussed the types of distributions that may...

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The Distribution of Tolerances

In a previous article the statistical tolerance stack-up analysis is discussed. It is usually profitable to do 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 article Worst-case Tolerance Stack-up Analysis you read about the worst-case or linear stack-up analysis. Such an analysis assumes that all dimensions in the tolerance chain have worst-case deviations form their nominal value. A statistical tolerance stack-up...

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Worst-case Tolerance Stack-up Analysis

Suppose that you went through your tolerance analysis step plan and made a tolerance chain. The only thing to do now is to add up all tolerances. This seems easy enough but there are a few questions to consider: What to do with asymmetrical tolerances? Do you perform...

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Tolerance Stack-up Analysis

Tolerances become important as soon as you design an assembly of parts. Of course each dimension must be provided with a tolerance. But in an assembly the tolerances become important because all parts must fit. In this article I tacitly will assume that we are dealing...

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Flexure hinges: theory and practice

The flexure hinge is a tried and tested construction element in precision engineering systems. It is created by drilling or spark erosion of two adjacent holes. The positive properties of flexure hinges, free of play and friction, are partly undone by the limited...

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