DFM Concurrent Costing 2.4

Transcription

1 DFM Concurrent Costing 2.4 Setting Up the Cost Estimation File This software will enable you to obtain an estimated cost of production for a component. As such, it can also be used to compare the costs of different production methods for the same part. You will a basic understanding of the various manufacturing processes in order to use this software. File setup and completing the header Set units under the Tools menu Fill in the Header Begin by naming the part and defining a part number*. Enter a predicted life volume value. The life volume is the total production number expected over the life of the design. This value will affect the per item cost. * Make sure that your team devises and agrees upon a number system for your components and subassemblies before starting. Define the part envelope This may be done using the CAD Import option.

2 Importing Geometric data from a CAD file. If the file was created in SolidWorks, Set the options for the import using Tools > CAD Options Select the most recent version of SolidWorks Open SolidWorks and open the file In Concurrent Costing, select; Analysis > CAD Import > Import CAD Results Make sure the file type is set to SW part file, then select the file. If the file was created in NX, set the CAD options as before In NX, export a Parasolid format file File > Export > Parasolid Pick the component in the selection window Set the destination folder and name the file Import the file into SolidWorks Open > Parasolid Save the file, then in Concurrent Costing, select; Analysis > CAD Import > Import CAD Results Set the file type to parasolid and select the file If the file was created in PTC Creo or AutoCAD Inventor, export either an IGES or STL file (IGES is more accurate) Open the file in SolidWorks, Save, then import CAD Results as before

3 Forming Direction Even after importing the geometric data from a CAD file, you will still however, have to define the Forming Direction. For near net shape production techniques (casting, forging, injection molding, etc.), the form direction is the direction in which the mold or die opens (perpendicular to the parting line). In the case of stock material, forming direction is the rolling or drawing direction. Select the Process and the Material If you select the material first, the software will then display suitable operations for that material, if you specify operation first, the software will display appropriate materials. We will use the component shown at right as an example for instruction. This part will be sand cast (semiautomatic) from gray cast iron. Once the manufacturing operation has been set, a listing of the operation tree will appear in the display window, and an information window will open. The information window will include information such as Basic Part Data and Part Geometry. NOTE: The information displayed is operation specific and hence will be different for different operation choices. Operation Tree Operation data such as Basic Part Data and Part Geometry

4 Modifying Operation Data The basic data displayed will have a number of default settings. Some may require alteration. For example, for castings the Number of Cores default value is set to zero. In the case of our example, this value will likely be changed. The number of impressions refers to the number of identical castings produced in one operation. The Pattern Complexity is based upon the number of surface patches in the solid model of the part. This value should have been determined in the CAD data import. Values modifies from the default will be highlighted. NOTE: If you have a question about any entry in a dialogue box, go to the Help menu, select Contents and Index > Topics > Index, then enter the entry listing (for example Batch Size) in the search window. Adding Machine Operations Most components will also require additional machining. Considering the cast part we are using for an example. This component will require surface milling, the drilling of holes, counterboring of holes and milling of the slot. Each of these operations needs to be specified for the component. This process requires both tool set up and definition of the machine operation. For example, for the surface milling of our component, the command string for tool set up would be as follows. Analysis > Insert Machine Tool Set Up > Milling Machine > Generic Vertical Knee Mill

5 For the operation (surface milling the base) the command string would be as follows. Analysis > Insert Operation > Machining > Face Milling > Rough and Finish Face Mill NOTE: The insertion commands can be found by moving the mouse to the part tree area and pressing the RMB. NOTE: You must Insert the Machine Tool Set Up before inserting the operation. You should specify fixturing prior to machining. This is done by selecting the Setup/load/unload entry in the process tree.

6 This will let you define the fixture type. The reason this is important is if you wish to repeat the same machine process on a different surface, you will have to re-insert the tool setup and re-specify fixturing. This reflects the time cost of unclamping, re-orienting and re-clamping the part. Certain data pertaining to the operation must be inserted in the open dialogue box. You will need to specify (at a minimum) the dimensions of face machined, the total material amount to be machined (removed), and the finish surface quality. Once these values are entered go to the bottom left area of the screen and select Calculate.

7 This will update the current part costs to reflect your new entries. Once the recalculation is performed, the other default settings for the machining process will be displayed. These include the cutter diameter, cutting and feed speeds, number of cutter passes, etc. for both the rough and finish cuts. Adjust as required based upon you machining knowledge. Make sure that you recalculate if you make changes. We could now continue and specify the face milling on the other faces. Set your fixturing based upon what is to be performed. In our example, milling will occur on one horizontal face and two vertical faces of our part. Because of this our set up will have to be changed during machining There are multiple holes in the part. We will next specify the machining of the two spotfaced holes.

8 Machining Holes Analysis > Insert Machine Tool Set Up > Boring and Drilling Machines > Generic CNC Drilling Center For the operation (surface milling the base) the command string would be as follows. Analysis > Insert Operation > Machining > Drilling > Drill Multiple Holes

9 The values of Diameter and Depth will have to be adjusted. The number of holes (if greater than 2) may also have to be set. The two holes will need to be counterbored (we use a shallow c bore for a spotface). Since we are using the same equipment (CNC Drill Center), at the same part orientation, no Setup is required, we can simply insert the operation. Analysis > Insert Operation > Machining > Drilling > Counterdrill Multiple Holes Again the values of diameter and depth will have to be adjusted

10 This document is not intended to be a comprehensive tutorial, but rather, simply an introduction to the software and some of its basic operations. The structure for other commands and operations is very similar to those shown. After completion of your cost estimation file, you will want some output of data. This is very easily accomplished with the commands under the Reports menu. Reports > Executive Summary This one page report, for a single analysis, presents cost data in both table and graph form. Choose it from the Reports menu on the main window to view and print it in the Print Preview window. The report includes, for the specified life volume and batch size, the following cost results for the part: Initial tooling investment Material cost per part Piece part cost Process cost per part Rejects Setup cost per part Tooling cost per part Total cost per part

11 Reports > Results The Results report, for a single analysis, presents all the cost results in table form. The report includes, for the specified life volume, all cost results for each operation in the standard process, the standard process total, totals for each secondary operation, and the total cost per part. The results include: Initial tooling investment Material cost per part Piece part cost Process cost per part Rejects Setup cost per part Tooling cost per part Operation time per part Total cost per part

12 Reports > Responses This text report includes all responses for an analysis, organized by Process Chart entry.