It may seem bizarre but in the high precision world of motion control engineering the way numbers are calculated in Primary school maths is inherently more accurate than digital processor calculations. Digital processing is not good at calculating real world numbers. As binary systems work in 0 and 1 representing some partial numbers or fractions is a problem. One third, one seventh, one eleventh are typical examples. Floating numbers were introduced to represent partial quantities Read more

Dec 192011

Torque is the third in the trio of tools, along with inertia and speed, which I need to work with to calculate the right size of servomotor for a project. When picturing Torque I like the analogy of the cyclists approaching a hill. The force delivered at the pedals to propel a cyclist up the hill will be the same regardless of the speed. The cycle’s gearing mitigates the steepness of the hill. Equally, if Read more


My experience tells me that the single most critical factor in designing efficient and effective dynamic positioning systems is specifying the correct size of servomotor. Why do I think this is so important? Because getting it right, apart from being personally very satisfying, will make a real difference to return on investment. It saves on capital cost – don’t buy more motor than you need It saves on maintenance cost – buy enough motor to Read more


In these three blogs I want to share what my experience has told me about the interplay of the three critical factors that determine the best servomotor for a specific job. It will always be one of inertia, speed and torque that takes the lead in determining the right motor and the ideal of most ‘bang for buck’. In my previous blog I gave my view on inertia as a criterion. Now it’s the turn Read more

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