4476 CMM Lab

Recommended Reading:

• Demystifying DMIS, Quality Digest

Objectives:

• Familiarize students with the the purpose and function of a CMM machine
• Develop an understanding of how CMMs define point geometry
• Reinforce spatial visualization skills
• Introduce students to the Dimensional Measuring Interface Specification (DMIS) language
• Introduce students to PC-DMIS software

Materials

• LATHE REVIEW INSPECTION PRINT
• Workpieces from TECH 4571

Procedure:

1. Power up PC
   
2. Power up CMM
   
3. Make sure the E-stop is out by twisting it gently.
   
4. Start the servos by pressing the “Enable Servos” button.
   • Hold it down until you hear the a “click.”
5. Be sure your tool stack looks like the photo below and the probe points straight down.
   
   If it does not, SEE YOUR INSTRUCTOR.
6.  Start PC-DMIS.
   • You will need to click “yes” at the dialog box that appears.
7. Start a new program.
   • Be aware that PC-DMIS defaults to opening an existing file.  Cancel this dialog box.
   • Name your file YOURUUID_4476_1
     • Note: UUID is Not your U001234 number.
   • Select INCH units.
8. Select “4476 Probe”
9. Click OK to home the machine
10. Jog the machine by holding either “T” button on the pendant while jogging the joystick.
    • USE “TURTLE MODE” when within 3″ of the part.
11. Ensure that the part is set up as shown here:
    
12. Enable the “Measured Features” toolbar.
13. Select “Measured Guess” mode.
    
14. Probe five points on the end of the small cylinder. Avoid the stamped letter.
    
15. Press “ENTER” on the teach pendant.
    • You should hear a chime.
    • A plane entity should appear in the DMIS program.
    • Rename this plane to END PLANE.
16. Now probe a series of 10-15 points on the small cylinder as shown:
    
    • If guess mode creates an entity other than a cylinder, delete all the points (and the entity) and re-probe.
    • Rename this cylinder to “SM CYL”
17. Probe the cone shape with 10-15 points as shown:
    
    • Rename this element CONE.
18. Probe the large cylinder with 10-15 points.
    
    • Rename this cylinder LG CYL
19. Create a constructed circle between the large cylinder and the cone:
    
    • Rename this circle “CIRCLE.”
20. Create an alignment
    • Name the alignment AL1
    • Position the alignment such that it is
      • LEVELED on the CIRCLE
      • ROTATED to the SM CYL
      • Origin on on the CIRCLE
    • You should notice the probe now appears in the display with your geometry.
      
21. Create a distance dimension between CIRCLE  and END PLANE.
    
22. Verify other dimensions , such as angle of the cone, and the diameters of the cylinders.
23. Write the actual dimensions on the inspection sheet.

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