Drawings supplied for the production of prototype parts or to receive a quote, will specify the overall tolerance required on the finished part and sometimes on specific dimensions. The tighter the tolerance, the more challenging it is to come up with the highest quality finished parts.

Numerous projects require a very high tolerance – this being the nature of prototype engineering. At Woodley Engineering, we have extensive experience of producing parts to a tight tolerance in prototype design and how that can be achieved. We use the latest turning and milling equipment coupled with manual fabrication skills to bring our clients the highest quality prototypes.

Tight Tolerance: What Is It?

Tolerance in prototype engineering is an acceptable deviation from the measurements and dimensions determined for a certain project. Usually, it’s written as “+/-“ value. For example, if the dimension for a given feature is 40 mm, the tolerance is a number slightly above or below the measurement. For example, +/- 0.1 tolerance means the dimensions can vary from 39.9 mm to 40.1 mm.

The smaller the tolerance value, the tighter it is. For example, 0.002 is an extremely tight tolerance.

A tight tolerance is not always good for a feature. All materials tend to contract and expand due to temperature changes. They wear out and change shape under a load or when faced with vibration. So no matter how perfectly the prototype is manufactured in a factory, it will change when used. That’s why the majority of objects need some room for manoeuvre.

Achieving High Tolerance

Our approaches to achieving high tolerance vary. They are aimed at meeting the client’s needs regardless of the project type, materials or deadlines.

Precision CNC Turning

Years of experience coupled with the latest equipment allow specialists to create precision CNC turned parts. Complex CNC turning requires a special approach to achieve a tight tolerance. Precision CNC turning can help manufacture the most delicate features.

It’s vital for the CNC turning machines to be compatible with the latest software in order to achieve the most precise results.

CNC Machining

CNC machining can help achieve tight tolerance if:

• Operated by a team of experienced specialists
• Supported by highly trained CNC programmers
• Checked by attentive quality control staff.

Getting quality finished parts to a high tolerance is much easier when you have the right equipment and the right specialists. However, a lot depends on how well the task is presented. The more time and effort the designer spends on the project and the more accurate the information on the drawing, the faster and more precise the engineer’s job will be.

Technical Factors Tight Tolerance Depends On

If we dig a little deeper into the process, achieving high tolerance is possible with the following considerations:

• Proper warm-up of the equipment
• The right choice of abrading and finishing tools
• Maintaining the right temperatures
• Properly calibrated equipment
• Tool compensation

At Woodley Engineering, we know that the latest CNC machines coupled with experienced engineers and software experts can allow us to achieve the tightest possible tolerance for all our projects. For more information about our services, please download our free Precision Engineering Guide by clicking here.