Manual CMM Home Position

A manual CMM that utilizes Non-Linear scale compensation must also have a home procedure which consists of either reference marks at a predetermined location along each axis scale or an instruction to position the CMM in a corner and then to reset the XYZ values.

On manual CMMs that do not have reference marks, the Geomet startup procedure will detect that the Home position has not been established and prompt the operator to establish home, see figure 1.

figure 1, Manual CMM Home Dialog

The prompt requests that the CMM be positioned in the upper right front corner of the measuring envelope. The operator should move the CMM into that position until all axis stops have been reached. When the CMM is in that position, press the <Set Home> or <Enter> key and Geomet will record this position as MCS (XYZ) 0,0,0.

NOTE: This method of establishing a Home position on a manual CMM requires the operator to hold the CMM against the stops for each axis. Most stops are made from an elastic material and therefore can not be relied upon to establish the MCS XYZ origin accurate enough to be used with File Recover operations. It is accurate enough to be used for Non-Linear applications.

This reference to Home will be maintained while Geomet is in operation, even through part program restarts and will reset when Geomet is closed.

On manual CMMs that utilize the Helmel ProCounter II CMM interface, reference marks, see figure 2, can be installed which are detected and used to set a absolute zero reference.

figure 2, Scale with Reference Mark

To establish Home, pass the CMM over the reference mark slowly and the internal position counters will reset to zero.

NOTE: This method of establishing a Home position on a manual CMM requires the operator to pass the CMM, slowly, over the reference marks for each axis. This method can be relied upon to establish the MCS XYZ origin accurate enough to be used with File Recover operations.

Related Procedures:

Home a DCC CMM, Scale Factors