When attempting to gauge the internal dimension of a part with any
accuracy, conventional metrology often requires the test piece to be
destroyed in order to view its internals. This is wasteful, particularly
if the part was correctly dimensioned in the first place. Now, Vision
Engineering has a non-destructive solution to this measurement problem in
Metro-Form, an extremely stable polymer that accurately adopts the shape
of an internal cavity or bore.
What you get is a kit comprising an applicator gun, putty, three types of
silicone-based polymer and a hardening agent. The gun mixes the silicone
compound and hardener automatically and delivers the mixture into the
part through a nozzle, of which there are many shapes and sizes. The
putty is used to block off any open channels and to create a grip point
for removing the moulding from the part.
Thanks to the silicone, the moulding is extremely flexible, so it can be
pulled from inside the part without suffering any permanent damage or
distortion. Once free, the moulding returns to the cavity's original
shape to within 0.04% in any dimension, so the internal features are
replicated to a high degree of accuracy for measurement purposes.