Automated inspection for the commuters choice in personal transport

Owners of Brompton’s don’t just own a bicycle; they own a product which through its designs and innovations is built to last. The ability to fold the bike into a compact unit which can easily be taken on public transport is the fundamental element of its design.

With their commitment to excellence and the high quality expected by its customers the company has decided that now is the right time to invest in twenty first century measurement equipment in the form of a DEA GLOBAL Performance coordinate measuring machine (CMM).

At its site in Brentford, London, Brompton Bicycle designs and manufactures the famous Brompton folding bike, an iconic sight on the streets of London for 30 years, and now increasingly seen in cities around the world. Brompton are proud of their heritage: when you enter their manufacturing facility the first thing you see is a mini museum of the original Brompton’s as designed by the bike’s inventor Andrew Ritchie.

Increase in throughput required

Whilst the fundamental design principals of the folding bike have remained the same since the original 1973 design, the product and manufacturing processes have undergone continuous improvement, especially in recent times. With the increase in sales Brompton has turned from manual to automated brazing and CNC machining. “In order to reach our output targets we have had to modernise the whole production process”, explains Greg Smith, Technical Support Manager. “Over the next few years the plan is that we will double our output, meaning that we have had to go through a complete change in our manufacturing.”

Taking a big step forward

It is because of this huge increase in output that Brompton needed the automated DEA GLOBAL Performance CMM from Hexagon Metrology for bike frame inspection. Inspecting 1 in 50 frames and sub-assemblies keeps the inspection room very busy. Terry Blackman, Quality Control Engineer at Brompton is extremely confident in the product he is assuring – so much so that his 12 mile journey to work each day is taken partly on the London underground and partly on his folding Brompton bike.

How to measure easily

When Brompton was looking at potential suppliers for the new CMM a particular focus was on the ease of use. “We were particularly impressed with the simplicity of the PC-DMIS CAD software which allowed us to quite easily achieve the results we needed”, explains Terry Blackman. “The hands-on training I had at Hexagon Metrology’s training centre was enhanced with a day onsite at our factory to further understand measurement techniques specific to our bike frames. I find the software very impressive, using it both with and without CAD.”

Prior to the installation of the DEA GLOBAL Performance CMM measurements and inspections on bike parts were carried out using basic principles. A multitude of hand tools and dedicated checking fixtures were in use. Whilst dedicated gauging offered a general check for manufacturing, it was time- consuming and inflexible when parts changed.

How to hold the parts

One of the challenges of measuring the bike frames with the CMM is being able to hold them in a suitable position in order for the probe to easily access all the features. Hexagon Metrology was able to cover this issue using its own fixture design and manufacturing service. A series of fixtures have been designed to hold the various parts. “Having these fixtures means that we can ensure extremely repeatable measurement”, explains Terry Blackman. “It is our intention in the future to have shop floor operators able to use the CMM unsupervised. Using fixtures makes this much easier as no manual alignments will be necessary. The operators can just load the part and click a picture on the screen.”

Significant purchase

The future certainly looks bright for Brompton. The increase in demand from environmentally concerned commuters is ensuring that the new DEA GLOBAL Performance CMM will be kept busy for years to come. Greg Smith is confident that the CMM will play a big part in securing the future of their product: “The CMM is probably the most significant capital purchase we have ever made.”