Manual WorkWork using CNC Machines
Manual layout required to cut the beam or to drill all holesAuto measurement is done and cutting and drilling operation is automatic, 70-80 % cycle time can be saved
Cutting quality is not satisfactory and one more operation of grinding is requiredSmooth finish is obtained since grinding is avoided and accuracy is achieved upto 0.1mm
Since the operation involves manual materials handling for cutting and drilling, the turning of the beams occurs at least 3 to 5 times, leading to chances of handling damages and accidents.No material handling is involved since cutting and drilling of holes takes place for all the sides of sections with the beam in one position.
Time taken to drill 100 holes of dia 22 mm in one beam of size 500x300x25x15x9000 mm long is approximately 400-420 min with a good fitter and cutterTime taken by CNC is approximately 30 minutes
Manpower required for material handling is more hence the man-hour spent per hour will be moreOnly two machine operators (For cutting and for drilling machines ) required to perform entire operation and hence less man – hour per ton
Chances of human error are more as the drawings have o be referred to on the shop floorSince CNC files are downloaded directly from the drawing software, chances of errors are almost negligible
Chances of human error are more as the drawings have o be referred to on the shop floorSince CNC files are downloaded directly from the drawing software, chances of errors are almost negligible.
When percentage of components is high in structures, time taken to prepare is long resulting in delay in fabricationWhen the percentage of components is high, mass production is possible which helps in cutting down the cycle time for fabrication.