SolidCAM 铣削手册(中).pdf

Training Course Geometries 172 Lesson #3 - Geometries 1. Objectives Adding Geometry Wireframe Geometry 3D Model Geometry Drill Geometry Geometry synchronization Geometry editing Geometry settings 2. Overview SolidCAM enables you to turn 3D models, 2D and 3D sketches built with SolidWorks into G-code for any CNC-machine. In this process of modelling to manufacturing, geometries have to be defined to determine where the model will be machined. In SolidCAM, you can define geometries in two places; in the Geometries field of the CAM- manager and in each job. Defining geometries in the Geometries field is only possible if the CAM- part uses projected type homes; otherwise, this field is inactive. It is recommended to define the geometry from the job dialog; this enables SolidCAM to check if the geometry follows the necessary rules needed in this type of job. There are types of geometries used in SolidCAM: Training Course Geometries 173 3. Wireframe Geometry Wireframe geometry has sub-types; each with its own set of rules. All the sub-types use the same interface to select the geometry. In this lesson, the common selection methods will be explained without the special rules relevant for each sub-type. Chain geometries are defined from the following entities: edges of models, 2D curves, 3D curves, circles, lines and splines. Each chain is composed from one or more entities and defines an open or closed contour. 3.1. Defining Wireframe Geometries When defining a wireframe geometry, the Geometry Edit dialog will be displayed: In this dialog, you can select chains with two methods: Add Multi-Chain This option enables you to select chains in the automatic mode. Add chain This option enables you to select one or more chains, one at a time. Training Course Geometries 174 Settings This dialog enables you to define the Spline approximation tolerance for the chain selection. Arcs on the XY plane are saved as arcs in the SolidCAM database; if you select an arc or spline that is not on the XY plane of the actual part home position, SolidCAM will do the following: Project the arc or spline on the XY plane of the active home and divide it into segments according to the specified tolerance. In order to reduce the number of segments, SolidCAM tries to fit arcs on the segments generated in step 1 according to the specified tolerance multiplied by 3. Training Course Geometries 175 3.1.1. Chain selection The chain selection options in SolidCAM enable you to select contours and boundaries quickly and easily. Whenever you have to define a chain geometry, the Chain options dialog will be displayed. Note You can switch between the different chain options when defining a chain. The default option is the Curve option in the Single Entities section; you can, however, start the chain definition with any other option. Training Course Geometries 176 Chain Direction In some of the jobs in SolidCAM, the direction of the chain geometry affects the toolpath calculation (for example, in Profile Milling you have to specify the tool side, relative to the direction of the selected contour). The edges or sketch segments that you select for the geometry are highlighted; the arrow at the start point of the chain indicates its direction. If needed, use the Reverse command to reverse the chain direction during or at the end of the chain selection. Edit bar Whenever you have to select a point during the chain selection, you can use the Edit bar to enter the X, Y and Z values in two ways: 20, 20, 30 or 20 20 30. Type the values and click on the Enter button. Training Course Geometries 177 Single Entities You can define the contour by selecting edges, sketch segments and points on the contour. SolidCAM provides three options: Curve You can create a chain of existing edges or sketch entities by selecting them one after the other. Pick start curve Select the start entity (a solid model edge or a sketch entity). Pick next curve Select the next curve that belongs to the chain. The curve must be connected to the previous curve; otherwise, the following message will be displayed: Associativity SolidCAM will keep the associativity to any edge or sketch entity. Any change made to the model or sketch will automatically update the selected geometry. Training Course Geometries 178 Point to point This option enables you to connect specified points; a straight line will connect the points. Pick start point If it is the first geometry element, either enter the coordinates into the edit bar or pick a point from the model. Pick next point A chain element will be created from the previous point up to this point; either enter the coordinates into the edit bar or pick a point from the model. Associativity SolidCAM will not keep the associativity to any selected point. SolidCAM saves the X, Y and Z of the selected points. Any change made to the model or sketch will not update the selected geometry. Note You cannot select a point that is not on a SolidWorks entity (if you need to select such a point, add a planer surface under the model and select the points on that surface). Training Course Geometries 179 Arc by points This option enables you to create a chain segment on an arc up to a specific point on the arc or to define an arc by any 3 points. Pick start point If it is the first geometry element, either enter the coordinates into the edit bar or pick a point from the graphic view. Pick next point Choose a point that represents the second point of the arc. Pick end point Choose the third point where you want the arc to end. Associativity SolidCAM will not keep the associativity to any selected arcs by points. SolidCAM saves the X, Y and Z of the selected points. Any change made to the model or sketch will not update the selected geometry. Training Course Geometries 180 Exercise #22 - Chain definition using Curve and Point to point options Open the SolidCAM Part: exerciseschain_definition.prt Right click on the F_Profile_T1 job and choose Edit from the menu. In the Geometry Name field, delete the geometry name string. Click on the Define button to start the geometry definition. To select the pocket on the top face: Click on the Add chain button. The Geometry Edit dialog will be closed. The Chain options dialog will be displayed. Training Course Geometries 181 You can start selecting edges or sketch elements. With the left mouse button, select the shown edge. Use the Reverse button to see how it affects the geometry. Use the Undo step button to eliminate the selected element. With the left mouse button, select the shown element. Training Course Geometries 182 Choose the Point to point option. With the left mouse button, select the point as shown. SolidCAM will connect the last point of the previous selected element and the selected point with a line. Choose the Curve mode. With the left mouse button, select the next entity. The steps above explained how to define a bridge element between two edges. Use the Undo step button to eliminate the selected elements. Leave the first selected entity selected. The following rules have to be understood when using virtual line selection by the Point to Point option: When you select a virtual line between two edges, the line will behave as a spring. Whenever the model is changed and synchronized, the geometry will be updated with the model. When you select a sequence of more than one virtual line, only the points connected to model edges or sketch elements will be updated, but all the other points will stay fixed at the defined X, Y and Z positions. This will now be demonstrated using two examples. Change the Chain option to Point to point. With the left mouse button, select the shown point. Training Course Geometries 183 Change the Chain option to Curve. With the left mouse button, select the shown element. Use the Finish button to save the selected geometry. The Geometry Edit dialog will be opened. Click on the Finish button. In the Geometry name dialog, type the name and click on the OK button. In the job dialog, click on the Save the position is not so important but it should be on the edge. Select the second geometry point on the corner vertex. Change the selected item in the geometry option to Arc by points. Select a point on the arc (point 2). Select a point on the arc (point 3). Click on Finish to save the selected geometry. Close the Geometry Edit dialog by clicking on Exit. Auto Select In the Auto Select mode, SolidCAM will automatically find the chain entities and try to close the chain contour. The Auto Select mode offers the following three options: Training Course Geometries 193 General Chain In the process of the chain selection, SolidCAM will highlight all entities that are connected to the previous chain entity; you have to select the entity that you want the chain to continue to. This mode is useful mostly in sketch selection (as you can see in the picture of the solid model, every edge is connected to at least two other entities). Constant-Z This option enables you to automatically select only the entities that are on the same XY-plane with the previously selected chain entities. You will be only prompted to identify the next chain element when two entities on the same Z-level are connected to the chain. The system tolerance for this option can be set in the CAM settings. This is the preferred selection method for a loop; however if you do not need the complete loop, you can use the Undo button to unselect the last entities. Delta-Z When you select this option, you will be required to enter a positive and negative Z deviation into the Delta-Z dialog. Only entities whose end point is inside this deviation range will be identified as the next possible entity of the chain. Training Course Geometries 194 Steps of Auto Select mode: If you have already selected some entities, select one of the Auto Select options to activate it. If this is the first geometry element, pick the start curve. Select the start entity of the chain. Pick point in chain direction - Indicate the chain direction by choosing a point on the selected start entity of the chain. If the system detects more than one entity that could be the next element of the chain, you will be prompted to select one of the possible curves; indicate your choice. When the system can close the chain, you are asked whether it is OK to accept; choose Yes to accept. If you answer No, you can edit the chain selection in the Chain options menu. You can, for example, undo the last step or cancel the chain selection. Auto to Point This command is useful if you do not want to define a closed chain, but rather an open chain upto a certain point. Note It is not possible to select the upto point on an entity; it can only be an end point of an entity. The Auto to Point selection offers three different options: All of the above three options are the same as Auto Select except that the chain is not closed but stops at the upto point. Steps of Auto to Point mode: Pick start curve - Select the start entity of the chain. Training Course Geometries 195 Pick point in chain direction - Indicate the chain direction by picking a point on the selected start curve of the chain. Pick upto vertex on chain - Select the end point of the end entity of the chain. You will be prompted to Pick one of the possible curves if the system detects that more than one entity could be the next element of the chain; indicate your choice. Confirm your chain with Finish in the Chain option dialog. Edit Chain Reverse This option enables you to reverse the direction of the chain you are currently working with. An arrow at the chains start point indicates the direction. Undo step This option enables you to undo the last selection of a chain entity. To delete the first chain entity, click on Reverse and then on Undo Step. Finish Confirms the selection of the chain and proceeds to the next step. To exit the chain selection without saving the selected entities, click on the X button. Training Course Geometries 196 Exercise #24 - Chain definition using auto selection options Right click on the geometry and choose Edit. In the Geometry Edit dialog, right click on Chain1 and select Replace. The geometry shown to the left will be added; this geometry can be used for cutting the pocket or profile. Choose the Curve mode and pick the first geometry element as shown. This element will enable you to set the direction. Training Course Geometries 197 Choose General Chain in the Auto Select section. SolidCAM will show you the entities that are connected to this point. You have to select one of the entities. You can also choose the Constant Z option. SolidCAM automatically creates a chain with the entities. SolidCAM will prompt you to accept the selected chain. Choose No. Click on Undo step. The last selected entity will be deleted. Click on Reverse. The chain direction will be reversed. Click on Undo step. The last chain entity from the other side of the chain will be deleted (first selected entity). Training Course Geometries 198 Exercise #25 - Chain definition on a sketch using auto selection tools Right click on the geometry and choose Edit. Right click on Chain1 and choose Replace. The geometry shown here will now be added (Sketch #6). Note This sketch is suppressed. Unsuppress it to define the geometry. Set the Curve mode and pick the first geometry element. This element will enable you to set the direction. Training Course Geometries 199 Since the sketch is only on the XY plane, selecting General Chain or Constant Z in this case will give you the same results. Note that the chain has stopped at the upper right hand corner of the sketch. There are two possible directions in which the chain can continue. Choose the entity marked by the arrow. The chain will continue in the direction you have chosen until it forms a closed chain. You will be prompted whether or not to accept the chain. To finish, choose Yes. Save the job and exit. Edit the sketch. Change the dimensions as shown. Finish and exit from the sketch. Synchronize and edit the assembly. When you click on the CAM Manager area, SolidCAM will prompt you to check the synchronization status. Click on Yes. Training Course Geometries 200 The synchronization marks will appear on the job and on the geometry. Right click on the Job name and choose Synchronize from the menu. SolidCAM will synchr