The great thing about the Indexable Stylus Changing System is that it replaces the need for separate articulating probes and changers. In this regard, the cost savings are dramatic – the Indexable Stylus Changing System costs about one-third of what you would pay for the same set up with separate articulate probes and changers.

It will work with any SCEPTRE System-equipped CMM, which includes our Legend IMC, CMMs made by Wenzel and Moore Tool Co. Of course, any CMM can be outfitted with the Indexable Stylus Changing System as long as it is upgraded to SCEPTRE System’s constant-contact scanning capability, which includes software, controller and analog probe.

The Indexable Stylus Changing System is composed of EMD’s analog probe-2, which has a stylus changer receiver built into the probe head, a removable stylus adapter head and a multi-docking-station stylus rack or changer.

Multiple stylus adapters may be used during any part inspection. A stylus adapter may be used to store a stylus cluster without having to break down the pieces, styli, extensions and angled joints. Several adapters can be placed on the stylus rack where they can be accessed under SCEPTRE System control.

Each stylus cluster may be indexed about the vertical axis in 72 positions or every five degrees for full 360-degree stylus articulation capability. For normal operation, the stylus cluster may be switched with another one in the stylus rack without the need for a stylus re-calibration. (For high-precision applications a stylus re-calibration is recommended.)

The stylus changer receiver is permanently built into the CMM’s probe head and contains a circular row of 72 precision spheres. At the center of the locator is an electromagnet that is energized only when the stylus is ejected. Because it is energized for only 100 microseconds during the ejection process very little net heat is generated.

The removable stylus adapter head contains a high-energy magnet that couples to the receiver on the probe head during normal operation. An iron cup contains the magnet’s magnetic fields, eliminating these fields from influencing measurement results on iron or steel parts.

A highly repeatable Kelvin coupling (i.e., kinematic locator) seats itself against three spheres on the stylus changer. The length of styli used on the stylus adapter head determines the repeatability of a stylus change. At the kinematic locator, the repeatability of an adapter is specified as +/-0.5 um or 20 micro inches. The repeatability of the angular location of the adapter is specified as +/-2 arc seconds. For extension lengths of every 200mm (8 inches) and additional 2um or 80 micro inches of uncertainty is added.

Normal CMM styli with M4 threads are available on this adapter. The adapter head has 17 receiving locations for styli, which are orientated in all the five primary axial directions

(-Z, +/-X, +/-Y). The adapter has four more styli receiving locations for elevation angles of –22.5, -45, and –67.5. Coupled with the azimuth ability to index the whole cluster every five degrees, there is adequate access flexibility.

Two types of docking stations are on the changer – "Fixed" and "Indexing." Only one "Indexing" station is needed because any stylus adapter may be transferred to the indexing station for indexing. For each stylus adapter, a fixed position station is required on the changer.