Wenzel America - Granite

Do your CMMs Have Rock Solid Accuracy & Durability?

Wenzel America Granite Article

Do your CMMs Have Rock Solid Accuracy & Durability?

Not All Measuring Machines Are Created Equal

CMM structures are not all the same. Some metrology companies have moved to aluminum alloy for their metrology material of choice because it is lighter and cheaper. The problem with this is that they sacrifice the very thing companies rely on most - ACCURACY. Their solution is to throw complex error-mapping software on top that “compensates” for the inaccuracy of the machines.

From an engineering perspective this is completely backwards and by no standard could this be considered an optimum solution. The only real benefit to anyone is a possibly a slightly lower cost machine for buyer and a better margin for the seller. Of course, the cost-benefit ratio goes out the window when you have to scrap thousands of parts or do a massive recall because your CMM didn’t produce the measurement and quality control data set you needed.

We build our CMM structures from granite, a naturally occurring material, millions of years old. Granite is the perfect structure for CMMs due to long term stability, resistance to temperature change and high stiffness.

For our premium LH Bridge and Gantry machines, we source granite from selected quarries in South Africa – this Black Impala stone has been found to be the most consistent, the least porous, and the most structurally and thermally stable.

Getting a quality CMM made of thermally-stable granite, involves a long process of skill and logistics, but ironically machines from Wenzel cost no more than other systems made from cheaper materials and processes.

When you buy from Wenzel you get coordinate measuring machine fit for a lifetime. A solid, stable metrological workhorse that gives consistent results over many years of service.

Why Black Impala Granite?

The story starts in South Africa – after many years investing and sourcing the best granite from the best quarries, Wenzel now works with a select few. Only a handful of quarries can handle the highest quality, large-sized pieces we need for our bridge and gantry machines.

Large blocks are literally ‘sheared’ out of the mountain, the end result looks like a tiered wedding cake!

Because of the lead time involved in mining and shipping the large raw granite blocks to Germany, where they will be cut, finished and hand-lapped to precision Wenzel standards, we pre-order blocks which are then mined and stored at the quarry. We base future orders of the huge granite slabs on past experience and order forecasts from our sales network.

These larger blocks remain at the base of the quarry until we need them.

Precision German Engineering - From Start to Hand Finish

The raw, rough blocks then make their way first by ship and then truck to Wenzel Steintechnik in Germany. Steintechnik have been processing granite since 1988 and for the last 8 years have been part of the Wenzel Group.

Large CNC saws cut the rough blocks to within 10mm of the finished size so that they are ready for more precise machining.

The granite is then ground, honed and polished to a flatness of +/- 2mm and any additional slots and inserts required are added.

The tables, X-beams and quills are then ready to make the 40 mile journey to the Wenzel Prazision factory in Wiesthal, Germany.

At Wenzel Precision, after a few days of temperature stabilization and relaxation of stresses, large CNC grinding machines are used to machine the components to the finished size.

This might be the end of the process for many, but at Wenzel there is one final stage that ensures the optimal, intrinsic accuracy.

Each part is then thoroughly inspected with laser interferometers to make sure the exacting flatness, parallelism, and square tolerances are met. Large tables are inspected with digital levels.

This inspection is particularly critical for the Z-axis quill as straightness of this part dramatically affects the accuracy performance of the finished CMM. If the grinding process has not delivered the required form, a team of skilled technicians will hand lap out any errors. The skill of these Wenzel engineers is unrivaled. Simply put, no other company has the experience or care to produce granite CMMs of this caliber.

These components are then assembled to become the most stable and intrinsically accurate CMM structures to be found anywhere in the world.

No other coordinate measuring machine company can compare to the expertise and standards Wenzel maintains in all of our machines. From our years of experience in sourcing the world’s best granite to the painstaking, laser-precise measurement and craftsman finishing, our processes and product quality are not duplicable.

Wenzel America is your North American Source for the worlds finest coordinate measuring machines. We proudly sell and support these products with the personalized customer service and training. We are always happy to answer any questions you have about CMMs, Gear Measuring Machines, CT Scanning services, pre-owned machines, Renishaw scanners or any other aftermarket coordinate measuring products or services.  

Visit our newly re-designed website for more information www.wenzelamerica.com. If your CMM is down and you need emergency repair of a measuring machine you can call us at  248.295.4300 24 hours a day, 7 days a week.


About Wenzel America
Wenzel America is a division of Wenzel Group GmbH & Co. KG, a 45-year-old, family-owned, world-leading manufacturer of metrology solutions. Wenzel America is a top supplier of both traditional CMMs, GMMs, and CT and non-contact 3D Scanning measuring machines to the North American aerospace, automotive and medical device markets For more information about Wenzel America contact President, Andy Woodward 248.295.4300 or email info@wenzelamerica.com

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