Fitting 360° of steel with 3D measurements

Author: Cornelia Dietz

Schmid Metallbau, founded as a classic metal workshop in 1993, offers today perfectly crafted products and solutions in the fields of metalworking, stainless steel processing and metal construction. To serve customers on large construction sites or commercial and industrial buildings, a total of 15 employees focus on metal construction and design where high-quality work and a high attention to detail is of utmost importance.

In the spring of 2017, the company was given an exciting new project – to design and construct an outward-facing railing for a newly-built helipad on the rooftop of a hospital in Ravensburg, Germany. To install the helipad’s built-in components, the railing was positioned along the edge of the structure in a circular way. To avoid all pre-installed components facing different directions and twisted or tilted, each individual holder was required to be measured and modelled individually.

Closing the steel belt

It was labour-intensive to manufacture a railing running around the helipad’s platform in a circular way. Metal was bent with a special tool, so everything could fit seamlessly when installed on site. A misfit would have caused the circle’s steel pieces not to match.

"It’s just like when you can’t close your belt anymore because you’ve gone past the widest hole," says Markus Schmid owner of Schmid Metallbau.

In addition to the outward facing railing, a steel net was installed. In a worst-case scenario, the net must withstand catching a falling helicopter.

A trip to BAU to find the right solution

Schmid Metallbau decided to visit the BAU exhibition in Munich, Germany, with the goal of finding a solution to these complex 3D measurement needs. The company found the 3D DISTO and approached a colleague who already owned the product. After listening to the colleague’s positive feedback and receiving a more detailed explanation of the product, the firm ordered the 3D DISTO right away.

The high-precision survey was taken from one position only using the 3D DISTO with the aid of an adapter plate mounted on site. The company designed a simple target plate where foremen could mount the tilted, pre-installed, outward facing components of the railing. The 3D DISTO was set up in the centre of the helipad so it could measure all 54 structural components at once. After re-positioning the 3D DISTO only twice in line with the three-point-method, measurements were quickly completed, and all data was transferred to CAD.

A cross between a surveyor’s robotic total station and a handheld DISTO

It would not have been possible to complete these measurements using conventional methods, such as a tape measure or a laser distance metre. The 3D DISTO was able to measure the 54 skewed components with millimetre accuracy from one position and measure each component in relation to one another.

“Data transfer is easy and straightforward, so you can start working straight away with the captured measurement data,” says Schmid. "As the person responsible for implementation, I want to be certain that the data is transferred one-to-one into CAD. The measured points are clearly transferred into CAD making easier the preparation of the work and making sure each piece will fit.”

In upcoming projects, Metallbau Schmid already sees many different use cases for its new 3D DISTO, from the installation of glass, metal cladding of outward facing staircases to staircase shape, height and depth.