|Milling of End Face - Course: Techniques for machining of material. Trainees' handbook of lessons (Institut für Berufliche Entwicklung, 18 p.)|
The setting-up of the milling machine and the milling of end faces ensues as follows:
- Check the functionality of the milling machine to be used (oil level control and lubrication according to the lubrication plan).
- Position the clamping elements (clamps, chucking screws and bolts, washers and accessories), the tools (chucking wrench, vice crank, milling tools, clamping means for milling tools) and the measuring and testing means.
- Check that the workpieces conform to the accompanying data sheets (dimensions and numbers).
- Align the workpiece clamping means (machine vice), the stopping means (stop strip, stop) and clamp the workpieces in single or multi-piece clamps.
- Clamp the milling tool onto the stub cutter arbor or directly into the milling spindle.
- Set the cutting values (rotational speed and rate of feed).
- Set up the cooling unit.
- Position the milling protective device or position the chip catch.
- Position the milling machine table in the processing location to the milling tools (X-Y-Z direction).
- Scratching, setting the milling depth and end face rough milling.
- Dimensional inspection, adjusting to the required length and end face final milling.
- Unclamp the workpiece, deburr the cutting edges and clean, control size accuracy and angularity.
- If necessary, undertake dimensional inspection and angular controls. Otherwise mill the end faces of all workpieces according to "position", that is to say rough and final milling ensues in accordance with the marked scale setting (manual adjustment of the saddle). Accordingly, it is necessary that the workpieces are positioned directly at a stop rest. In the absence of a stop, the required size would have to be reset for each workpiece.
- If a second end face must be milled on the workpiece then proceed as for the first face side.
- When handling measuring and testing means, heed the ambient temperature for measuring and testing. Workpieces which warmed up during milling shall only be checked at normal room temperature.
If workpieces are measured and tested at a temperature over 20° C measurement errors may result because of length extension!
- Where end faces are simultaneously milled on a horizontal milling machine the required workpiece length is attained by means of a gang cutter. The gang cutter consists of two cylindrical cutters and the inbetween positioned milling arbor and spacers. These end faces are immediately milled to their final length in one work process. Rough milling becomes unnecessary when gang cutters are used. The maximum workpiece length which can be processed by using gang cutters is limited by the length of the stub cutter arbor (cutter arbor - long).
- After having completed the work process the milling machine and all tools, measuring, testing and accessory equipment must be cleaned.
Which preconditions must be fulfilled for attaining the angularity of end faces?
Which measuring and testing means are employed to check dimensional and positional deviations of milled end faces?
What limits the length of the processed end faces when using gang cutters?
How can cutting injuries be avoided when handling sharp-edged workpieces (burr at the cutting edges)?