Operations with Shaping Machines - Course: Mechanical Woodworking Techniques. Instruction Examples for Practical Vocational Training: Instruction Example 4.4.: Workpiece with Quarter Chamfer

Operations with Shaping Machines - Course: Mechanical Woodworking Techniques. Instruction Examples for Practical Vocational Training

		(introduction...)
		Preliminary Remarks
		Instruction Example 4.1.: Workpiece with Fold
		Instruction Example 4.2.: Workpiece with Groove
		Instruction Example 4.3.: Workpiece with Tenon
		Instruction Example 4.4.: Workpiece with Quarter Chamfer
		Instruction Example 4.5.: Workpiece with Quarter Round Chamfer

Instruction Example 4.4.: Workpiece with Quarter Chamfer

Milling a profile within the area accounted for by the workpiece narrow face, employing a chamfer milling machine.

Figure

Material

Solid wood piece, levelled and milled to a thickness of 20 mm with narrow faces abutted.

Dimensions:

Minimum length: 350 mm
Minimum width: 100 mm

Machines and tools

Shaping machine, chamfer milling machine

Diameter about 80 mm
Radius about 8 mm

(according to tool set at the machine)

Measuring and testing means

Folding rule

Aids and labour safety facilities

Spring-loaded comb

Necessary preliminary knowledge

Extensive knowledge of the assembly and function of a shaping machine besides all the essential labour safety measures whilst milling. Read drawings, measuring and testing.

Sequence of operations	Comments
1. Position the work materials and check tools and machines in respect of sound technological condition.	Workpiece length and width are determined by labour safety requirements and must not fall below these dimensions!
2. Mark the rest and bearing surfaces on the work-piece by means of a square sign.	The face of the workpiece to be worked should not feature any knots or knot ends.
3. Attach the tool to the cutter arbor and employ table spacers in line with the tool diameter.	The tool is attached in counter direction to the lower part of the cutter arbor. The spindle arrest is removed following firm chucking.
4. Set the spindle height at 8 mm between tool top side and machine table.	Position a short, straight strip onto the cylindrical cutter and control the measure of the spindle setting by means of a folding rule.
5. Set the guide rule at 8 mm to the knife cutting circle and arrest.	A tool cutting edge is turned to the maximum engagement size vis-a-vis the stop face. Position the workpiece parallel to the guide rule on the tool cutting edge and control the measure.
6. Align the stop faces to the knife circle.
7. Attach the pressure comb to the stop faces of the guide rule.	The pressure comb should completely enclose the tool vis-a-vis the stop faces.
8. Check the proper functioning of the machine.	Ensure that the machine table is clean. Ascertain that the tool, stop and spring-loaded comb are firmly positioned and check the spindle for unimpeded running.
9. Switch on the exhaust, switch on the main machine switch, preselect the spindle (3000 min^-1) and switch on the machine.	Ensure the correct rotational direction (counter running) of the spindle as an incorrect rotational direction can lead to serious accidents!
10. Mill a chamfer. Move the workpiece slowly and evenly towards the tool.	Position the workpiece with the broad reference face onto the machine table and with the envisaged narrow face to the right rule face.
11. Remove the processed workpiece and switch off the machine, main switch and exhaust facility.
12. Control the measure and attained quality.	Watch out for chipped edges. The chamfer should not evidence any unevenness as hollow chamfers can only be reworked by means of extensive manual operations.

Possible addition

Further chamfers can be milled along the remaining longitudinal edges of the workpiece. Thereby, heed possible slight changes in the workpiece grain sequence and reduce the rate of speed accordingly.

Figure