NIMS CNC case studies
NIMS CNC · Put your knowledge to work in context.
The NIMS CNC credential is a industry-recognized certification for machinists who set up and run computer numerically controlled milling and turning equipment. NIMS awards credentials per duty area, so a candidate can earn recognition in CNC milling, CNC turning, or both, and stack those credentials with related machining certifications over time. The NIMS CNC case studies are 5 cases and about 3,595 words.
1The Zip-Tied Interlock on a Friday Deadline
At 14:20 on a Friday, the chip conveyor on a 40-taper VMC stalls mid-cycle during a 900-piece run of 6061 brackets. 240 pieces remain and the truck leaves at 06:00 Monday.
721 words, about 4 min2Bonus Tolerance at MMC: Rework, Ship, or Scrap?
A lot of 120 anodized aluminum housings is at final inspection. The drawing specifies a Ø10.0–10.1 through hole, position Ø0.2 Ⓜ to A B C, and a general note that position may be verified by functional gauging.
669 words, about 3 min3The Bore That Read Good for the Wrong Reason
The finish bore on a 6061 aluminum housing is Ø50.000/50.025 mm. A machinist checks the first article with a two-point bore gauge zeroed on a 50.000 mm steel setting ring and reads 50.009 mm - inside tolerance.
723 words, about 4 min4A 0.4 mm Step Where the Cutter Comp Engaged
A 2.5D finish pass around a 60 × 40 mm pocket wall in 6061 uses a 12 mm, 3-flute carbide end mill with G41 D21. The entry is G1 G41 X20.0 Y-4.0 D21 F600 - a 4.0 mm linear move perpendicular to the wall at Y0 - followed by G1 X20.0 Y0.0 and then the contour.
785 words, about 4 min5Six Marks per Revolution
A 4140 PH (30 HRC) block is face milled with an 80 mm, 6-insert face mill on a 40-taper VMC: 600 rpm, 0.15 mm/tooth, 1.0 mm depth, 50 mm radial width, dry. The finish shows a regular pattern of six evenly spaced marks per cutter revolution, about 0.02 mm deep, with no audible squeal and a steady 55% spindle load.
697 words, about 3 min