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.


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

Tangential Load in HertzWin

With the program HertzWin you can calculate Hertz point and line contacts. The influence of a tangential load can also be calculated. HertzWin has been available online for free since March 2009. In older releases of HertzWin (prior to release 3.1.2) a general...

read more

Advanced Method of Tolerance Analysis

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

read more

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...

read more

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. In such an analysis it is assumed that all dimensions in the tolerance chain have worst-case deviations form their nominal value. In a statistical analysis...

read more