A portable CMM arm can reach parts too large or heavy for a typical arm-type CMM. However, they are only ideal for some applications.

The required inspection type is the most significant factor when determining whether or not a portable CMM arm is needed. You should also consider the accuracy requirements of your product.

You Need to Measure a Large Part

A portable CMM arm may be a good option for measuring a large product. With a modular wrist or handle, these machines can quickly get into tight spots to inspect a part.

They also offer flexibility for various applications, from reverse engineering to quality control and inspection on the shop floor. Unlike stationary programmable CMMs, which must be fixed to the granite table and measured based on X, Y, and Z coordinate systems, an arm can move with a probe to quickly measure different angles of a part.

When deciding on a portable CMM arm, know your accuracy requirements. Accuracy levels vary, and prices tend to correspond with them. Ask your solution provider what measurements will be needed and whether or not the device can scan a 3D object. This will help you narrow down the available options for your needs. These devices typically come with host software that satisfies simple measurement needs by probing or scanning.

You Need to Measure a Deep Part

Using an arm-type CMM to take measurements on the shop floor is much more flexible than traditional quality control tools like calipers and micrometers. They also allow you to measure areas not easily accessible with other handheld devices, such as a rotary table or photogrammetry systems.

Generally, you’ll want to determine your accuracy requirements before purchasing a portable CMM. Portable CMMs come in a wide range of accuracy levels, and higher accuracy models tend to cost more.

You’ll also need to know how complex an object you need to measure and if it requires scanning capabilities. Most portable CMMs have host software that controls the device to gather 3D scan data. Depending on the manufacturer, some come with metrology software, making them a turnkey solution for inspection and reverse engineering applications. Leussink offers a wide selection of Tomelleri articulated measuring arms, compatible CMM software, and Demmeler welding tables to offer an entire system that works together.

You Need to Measure a Narrow Part

If you need to measure a part with very narrow spaces, you may need a portable CMM arm. Knoche says arm-style CMMs allow inspectors to take measurements of components while they are still integrated into the fixture, which cuts inspection time and machine downtime. These systems offer a more cost-effective option than a traditional stationary programmable CMM.

These manual articulating CMMs, or measurement arms, use encoders on multiple rotation axes to determine the probe’s position in 3D space. This allows them to reach around or into parts for 3D inspections, tool certifications, CAD comparisons, dimensional analysis, reverse engineering, and other metrology tasks. They are an excellent choice for reducing product defects and meeting strict quality standards. The articulating joints on these portable CMMs can be manipulated by hand to get into hard-to-reach spots. They can also incorporate touch or noncontact laser scanning to collect data quickly and accurately. The resulting data is then fed into software for analyzing the part’s geometry and dimensions.