Case Study – Replication of a key dating back to 1700’s using PolyWorks® Software

PolyWorks® Case Study

Replication of an original working hand-made Blacksmith’s key from an old farmhouse in Rhone, France.

3D Scanners UK were approached by a private customer, who required a replica key to his recently purchased farmhouse.

In 2001 a farmhouse, which was originally a silkfarm dating back to the 1700’s became available to purchase. Our customer bought the farmhouse, however only one key to the front door was found. This key was originially handmade by a local Blacksmith when the farmhouse was first built.

Before approaching 3D Scanners, our customer had already asked a Blacksmith who specialised in old locks and keys for churches, to replicate the key. Unfortunately, the slight misshape in the key & the irregular teeth proved too difficult to replicate and it failed to unlock the front door.

3D Scanning

We 3d scanned both keys separately in our laboratory (based in Coventry) using the ATOS Triplescan.

The photograph on the left shows the keys being scanned at the 3D Scanners laboratory in Coventry.

Scan Data

Once the scan data from the two keys had been captured in the lab, the scan data from both of the keys were then imported into PolyWorks Inspector for deviation analysis.

Deviation Analysis – PolyWorks Inspector™

From the data analysis, the handmade Blacksmiths replica key has a deviation of over 1mm in some places around the teeth. This discrepancy is why the key unfortunately failed to unlock the door.

PolyWorks Modeler™

The engineer then began the process of tidying up the data using PolyWorks Modeler software. This allows the most accurate data to be used whilst producing a smooth watertight polygon model. The polygons were decimated to .2mm.

3D Scanners supplied our customer with an stl file of the polygon model ( visual representation shown above within Polyworks Modeler ). This was then imported by 3D Systems Ltd to produce a replica key in Maraging Steel using Direct Metal Printing (DMP). This process had a surface finish resolution of approximately 5µmRa.


The new key which was produced, performed as if it were the original key. View the deviation analysis inspection report here.