First perform rough machining of sand casting mold template, create a tool with diameter d = 40mm and fillet radius r = 5mm, then create a process, select the tool just created, and select cavity milling, mode selection rough machining, strategy selection depth first, and cutting mode selection follow parts. The step distance is set as the percentage of tool straightness, and the value is set as 90%. The depth of each tool is constant. Since it is the first roughing and the processing blank is aluminum alloy, the maximum depth of each tool is set as 3mm. Allowance setting in cutting parameters.
The feed mode of the tool is spiral feed, and the spiral diameter is set to 33mm. In this paper, the unified selection method of spiral feed diameter is; The maximum diameter of the spiral is D.R of the selected tool and the minimum diameter is d-2r. The final selection range of spiral diameter is between the maximum diameter and the minimum diameter. The flat head tool is slightly adjusted and will not be repeated. Here, the minimum diameter of helix is 30mm and the maximum diameter is 35mm. Therefore, the helix diameter is taken as 33mm. As it is the first roughening of the blank, the transfer type set for tool crossing and transfer, feed and retract is the safe plane distance, that is, after the tool retracts and leaves to the safe plane height, the next approximation and feed can be started. The rotation speed of the main shaft is set to 1400. After the processing parameters are set, the rough machining of the sand casting mold template is carried out to generate the tool path. The tool path after generation is shown in Figure 1.
Copy the blank roughing process created above, create a milling cutter with diameter d = 30mm and lower fillet radius r = 2mm, and select this cutter. Reduce the depth of each tool to 1.8mm, and select the layer based method in the drop-down menu of cutting parameters – space range – Blank – workpiece under processing. Each time a new tool is created, the compensation parameters for tool change need to be set according to the size difference of the tool, which will not be repeated below. The setting of other parameters remains unchanged, and the secondary roughing process is generated. The tool path diagram is shown in Fig. 2A. After the roughing of two cavity milling, the roughing stage of sand casting mold template is completed. The processed 3D simulation results are shown in Fig. 2B. It can be seen that the large structure outline of sand casting mold template has been completed and the surrounding positioning holes have been processed.