WORKBOOK MODELING OF MULTI- MEMBER MACHINES

WORKBOOK MODELING OF MULTI- MEMBER MACHINES LUBLIN 2014 0

Author: Mirosław Ferdynus Desktop publishing: Mirosław Ferdynus Technical editor: Mirosław Ferdynus Figures: Mirosław Ferdynus Cover and graphic design; Mirosław Ferdynus All rights reserved. No part of this publication may be scanned, photocopied, copied or distributed in any form, electronic, mechanical, photocopying, recording or otherwise, including the placing or distributing in digital form on the Internet or in local area networks, without the prior written permission of the copyright owner. Publikacja współfinansowana ze środków Unii Europejskiej w ramach Europejskiego Funduszu Społecznego w ramach projektu Inżynier z gwarancją jakości dostosowanie oferty Politechniki Lubelskiej do wymagań europejskiego rynku pracy Copyright by Mirosław Ferdynus, Lublin University of Technology Lublin 2014 First edition 1

TABLE OF CONTESTS 1. Model of the tilting pad.... 3 2. Model of the spherical knob. 4 3. Model of the rod... 6 4. Model of the cap... 9 5. Model of the nut.. 14 6. Model of the screw... 18 7. Model of the body 24 2

The main purpose of this publication is to present the basics of solid modeling on the example of a specific device. Design exercises are supposed to enable the repetition of basic function and procedures in solid modeling. The adequate level of detail allows the independent work for people who previously did not use Catia v5 system. The order of subsequently performed elements of the screw jackr, results from their degree of difficulty. The participants of the course are guided toward more and more increased proficiency in handling of Catia v5 system. The individual elements of the jack will comprise separate files, which a participant will save in his own directory. We begin the design exercises with creating your own folder on the desktop. Then, we run Catia v5 system using the icon on the desktop. The lift s project is implemented in the Part Design environment, which is launched with the command: Start + Mechanical Design + Part Design. 1. Model of the tilting pad Tilting pad of the screw jack will be implemented using a method of base profile rotation. Open an empty file and in the structure tree name this part as tilting pad. Base profile must be implemented in the yz plane. Run Sketcher module and mark the mentioned plane in the plane selection tool or in the structure tree of the module. The profile can be drawn in two stages. In the first, an arc must be created using the Arc function and its center must be attached to the V axis, while the arc s endings for the convenience of drawing, end on H and V axis. Arc radius should be dimensioned with the use of Constraint tool. It s very important to make sure that the system has created Coincidence constraints, which are visible on the screen in the form of a green circle (fig.1.1a). If you didn t draw the profile in a way that would create the constraints automatically, then you must add them manually. a) b) c) Figure 1.1. Stages of creating the tilting pad profile, completed model of the pad In the second stage, the missing part of the profile must be drawn with the use of Profile function (while drawing an open profile you need to remember about the double click when you want to end profile or about the double Esc when you forget to end it). Exit Sketcher using the Exit workbench button. 3

Model of the tilting pad is formed through rotating the created profile by 360 o angle around the V axis, using the Shaft tool (fig.1.1c) Save the file in your directory and close it 2. Model of the spherical knob Spherical knob in the screw lift is an ending of the rod, through which the drive is implemented. Like the tilting pad, it will be created using a method of base profile rotation. Also, similar tools will be used to implement this profile. Open an empty file and in the structure tree name this part as knob. 2.1 Implementation of the main solid of the model Base profile must be implemented in the yz plane. Run Sketcher module and mark the mentioned plane in the plane selection tool or in the structure tree of the module. The profile can be drawn in two stages. In the first, an arc must be created using the Arc function and its center must be attached to the center of the coordinate system, while the arc s ending must be attached in some distance from this axis. Arc radius should be dimensioned with the use of Constraint a) b) c) tool (fig. 2.1a). Figure 2.1. Implementation stages of the spherical knob profile and model of the knob without the threaded hole The profile can be completed using the Profile function (while drawing an open profile you need to remember about the double click when you want to end the profile or about the double Esc when you forget to end it). It s very important to make sure that the system has created Horizontal and Vertical constraints on the appropriate edges (fig. 2.1b). If you didn t draw the profile in a way that would create the constraints automatically, then you must add them manually. Exit the Sketcher using Exit workbench button. Model of the spherical knob is formed through rotating the created profile by 360 o angle around the V axis, with the use of Shaft tool (fig. 2.1c). 4

2.2 Creation of the threaded hole in the knob The last stage in the construction of spherical knob model is the creation of the threaded hole M8. In order to do this, you need to use the Hole tool. Select the plane in which an hole is supposed to be created and click near the place where you want to place it. A window will appear, in which you need to set the parameters as shown in figure 2.2a, b. If you want to create the threaded hole, then the parameters must be set starting from the third tab - Thread Definition. This way some of the parameters in the first tab will be set automatically from the thread library. In the first tab in Bottom option, you can declare the shape of the hole s bottom. a) b) c) d) e) Figure 2.2. Implementation stages of the threaded hole in the spherical knob In option Positioning Sketch you need to definitely set the localization of the hole in the space (sketch in option Hole fulfills positioning function and contains only the point visible as a white asterisk). In this case, it s best to use Coincidence constraints, available in Constraints Defined In Dialog Box. You need to move the white point to the side, mark it along with the Origin point, while holding down the Ctrl key (figure 2.2c). Then, you need to set the Coincidence constraints (figure 2.2d) asterisk changes its color to green which means that it has been clearly assigned. Then if you exit the Sketcher using Exit workbench Hole is going to be carried out. The final result is shown in figure 2.2e. Save the file in your directory and close it. and confirm the hole s parameters with OK key, the operation 5

3. Model of the rod In the designed screw jack, the drive is implemented through the rod. It will be created using a method of base profile rotation. To implement the profile, you may use the universal Profile function. Open an empty file and in the structure tree name it as rod. 3.1 Implementation of the main solid of the model Base profile must be implemented in the yz plane. Run Sketcher module and mark the mentioned plane in the plane selection tool or in the structure tree of the module. The profile can be drawn in two stages. a) b) c) Figure 3.1. Implementation stages of the rod profile In the first, a sketch must be created using the Profile function as shown in figure 3.1a and it s best to draw it in clockwise direction due to its arc. It s very important to make sure that the system has created Horizontal and Vertical constraints on the appropriate edges. If you didn t draw the profile in a way that would create the constraints automatically, then you must add them manually. Coincidence constraints must be added manually between the middle of the arc and the edge that is marked with orange line in the figure. In the second stage, the profile must be dimensioned with the use of Constraint tool. Due to the fact that the target profile is supposed to be extended in one direction, it s convenient to modify its dimensions in thought out order. Figure 3.1b shows dimensions of the profile. Dimensions in black color must be set first and dimensions in red color are unchanged arbitrary and must be set in accordance with figure 3.1c, starting from the larger one. Exit Sketcher using the Exit workbench Using the Shaft button. tool, we implement the model of the solid through rotating the created profile by 360 o angle around the H axis. The results of this operation are shown in figure 3.2. 6

Figure3.2. Effect of Shaft operation Figure3.3. Creating the chamfers in the rod model 3.2 Features supplementing the model Features supplementing the model are all kinds of roundings, chamfers, tilts, etc. In a rod that we re designing, it s necessary to make chamfers with dimensions 0.5 x 45 o at its ending. The edges marked in figure 3.3 with red line must be chamfered with the use of Chamfer tool. The effect of this operation is shown in the figure below. Ending of the rod should be threaded in order to enable the fixing of the knob. To create a thread on the outside surface, we need to use the Thread tool. After starting this function, we must define parameters of the thread by selecting the appropriate settings in the appearing windows, as shown in figure 3.4. As Lateral Face surface, you need to select the cylindrical surface marked in green in the figure and as Limit Face the front plane marked in purple. This operation will result in assignment of thread s feature to the surface of cylindrical ending of the rod (thread will not be visible on the screen figures 3.4 and 3.5, but as a feature of the model, it will appear in the structure tree). Figure 3.4. Creation of the thread on the rod s ending The next stage is the creation of the mirror image in respect to zx plane. This operation is carried out with the use of Mirror tool. The most effective way to do this is to perform these operations in the 7

following order: highlight the Part Body in structure tree of the model, run Mirror function and point to zx plane marked in figure 3.5 with yellow color. The complete model of the rod is shown in figure 3.6. Figure 3.5. Half model of the rod Figure 3.6. Model of the rod Save the file in your directory and close it. 4. Model of the cap Open an empty file and in the structure tree name it as cap. 4.1 Implementation of the base part of the cap Base profile of the cap must be implemented in yz plane with the use of the Profile dimensioned with Constraint tool as shown in figure 4.1. tool and Exit the Sketcher using Exit workbench button. Solid model of the cap is created through rotating the base profile by 360 0 angle in respect to vertical axis of the coordinate system - Shaft tool figure 4.2. Figure4.1 Base profile of the cap Figure 4.2 Solid model of the main part 8

The cap will be fixed with the use of push screws. Prior to the implementation of the holes in the cylindrical surface, a milling operation is conducted in order to obtain the proper support for the drill. The removal of material from the side surface of the cap model will be carried out using the method of subtracting other solids from the cap solid in this case: two cuboids. To do this, using the command from the top menu - Insert/Body, we put a new solid Figure4.3 Base profile of the cuboid object into the structure tree, which we name Prism ( command Properties - tab Product). Base profile of the cuboid must be implemented in yz plane using the Rectangle tool and dimensioned with the use of Constraint tool in a way presented in figure 4.3. During the drawing of the profile presented in Fig. 4.3, after you ve drawn the rectangle, you need to assign Coincidence constraints between the appropriate edges of the cap and the horizontal sides of the rectangle. Exit the Sketcher using Exit workbench button. Cuboid is obtained by pulling the base profile to dimension of 20 mm with the use of Pad with option Mirrored extent. After creating the cuboid with the use of Mirror tool, tool, we need to make its copy in regard to zx plane (first, we need to select Prism in the structure tree and after we start the Mirror tool, we need to indicate zx as a plane of symmetric reflection) figure 4.4. Figure4.4. Implementation stages of the cuboid models Then, with the use of Remove tool, we need to subtract the created Body named Prism from the cap solid. The effect of this operation of subtraction is shown in figure 4.5. Figure 4.5. Results of the subtracting cuboids operation Threaded holes M5 must be implemented in the obtained flat surfaces. In order to do so, first you need to determine a point in the middle of a flat surface using Point the Reference Element tool from menu, with option On Surface. In the dialog box called Point Definition in the window Distance, we need to enter the value 0. Process of point determination is shown in figure 4.6. 9

Figure 4.6. Entering the center point of the plane Threaded holes M5 must be implemented using the Hole tool. Prior to the starting of this function, we must select the created point. Then we launch the Hole tool and select a flat surface of the milling. Such order guarantees that we will not have to position the Sketch (we can check it in the Positioning Sketch window there s a green asterisk there, which indicate a full parameterization). Hole s parameters must be set in accordance with figure 4.7, starting from the Thread Definition tab, and then going to the Extension tab. After completion of the above-mentioned step, we will obtain two holes with M5 thread - figure 4.8. Figure 4.7. Parameters of the Hole tool Figure 4.8. Result of the Hole operation 4.2 Implementation of the notches on the surface of the cap model Material notches on the top surface of the cap must be implemented in two mutually perpendicular directions, based on the same base profile. 4.2.2 Implementation of the notching tool s profile Base profile should be implemented in the yz plane. Run Sketcher module and mark the mentioned plane in the plane selection tool or in the structure tree of the module. To obtain the intersection of the solid with a Sketch plane, we need to use Cut Part by Sketch Plane drawn in four steps: function. The profile can be 10

In the axis of created rotary solid, we draw a vertical line Figure 4.9. Stages of outline drawingstep 1 using Axis function and system should automatically assign Coincidence and Vertical constraints, if it does not, then it have to be done manually (figure 4.9). In the created axis using the Centered Rectangle function draw a rectangle and using the Constraint tool assign a dimension of 2 mm, which represents the depth of subsequent selection (figure 4.10). We delete Vertical constraints from the vertical edges and by gently pulling the corner of rectangle, we transform it into the trapezoid as shown in figure 4.11. Figure 4.10. Drawing stagesstep 2 Figure 4.11. Drawing stages step 3 Figure 4.12. Drawing stagesstep 4 We assign the other dimensions in accordance with the figure 4.12. Exit the Sketcher using Exit workbench button. The semifinished cap, along with the created profile is shown in figure 4.13. Figure 4.13 Semi-finished cap along with the profile of notching tool 4.2.3. Implementation of the grooves in the selected direction A single groove can be implemented using the Pocket tool and as a secondary option in the first and second limit we must select Up to next. The result of this operation is shown in figure 4.14. In the structure tree of the model, we need to change the name of the function Pocket to milling ( Properties command - Feature Properties tab). 11

milling Figure 4.14. Semi-finished cap with a single groove. Changing of the name of the function in the tree structure To duplicate the groove, we must use Rectangular Pattern function. In order to do so, it s best to highlight the milling in the structure tree and then run Rectangular Pattern function. Figure 4.15. Window of the Rectangular Pattern option As Reference Element we need to indicate the top surface of the semi-finished product. In the tabs: First Direction and Second Direction we set the parameters as shown in figure 4.15. Button More >> enables to expand the window with very useful functions that allow to obtain the effect of feature duplication on both sides of the original groove. Figure 4.16 shows the operation of grooves duplication in the rectangular manner and with the end results of this stage. Figure 4.16. Creation of the first row of the grooves 12

4.2.4. Implementation of the grooves in the perpendicular direction Figure 4.17. Semi-finished product of the cap after copying the groove to zx plane The next stage of the work is to copy the milling feature to zx plane. We do it in the structure tree ( milling Copy command Paste command). To distinguish the two millings, we change the name of the last to 4.17. milling2. The result of the copying is shown in figure We again need to use the Rectangular Pattern Second Direction we set the parameters as shown in figure 4.18. function. In order to do so, it s best to highlight the milling2 in the structure tree and then run Rectangular Pattern function. As Reference Element we need to indicate the top surface of the semi-finished product. In the tabs: First Direction and Figure 4.18. Window of the Rectangular Pattern option Figure 4.19 shows the operation of grooves duplication in the direction perpendicular to the first series, along with the end result finished model of the cap. Save the finished file in your own directory and close it. Figure 4.19. Creation of the second row of grooves. The end result finished model of the cap 13

5. Model of the nut Figure 5.1 Profile of the nut Nut of the screw jack is going to be implemented through the rotating of the base profile (Shaft function). Trapezoidal thread will be implemented as a result of the Slot operation, where the Helix screw line is used as a central curve. Open an empty file and in the structure tree name this part as nut 5.1. Implementation of the basic axially solid. Define new Sketch in the yz plane. Indicate the mentioned plane and run function. Using the Profile function draw the base profile as shown in figure 5.1, while making sure that its orientation in respect to the coordinate axes is correct and that appropriate geometric constraints are assigned. Then, assign the dimensions using Constraint Exit the Sketcher using Exit workbench button. With the use of the Shaft tool, implement the axially symmetrical solid through rotating the base profile by 360 o angle around the V axis. This solid is shown in figure 5.2. 5.2. Implementation of the chamfers. Using the Chamfer tool. function, we implement the chamfers with dimensions 4 x 45 o of inner edges of the hole. The most convenient way to do this is to indicate the inner surface of the hole, and then the system will carry out the chamfers on both edges. The effect after the implementation of this operation is shown in figure 5.3. Figure 5.2 Effect of the Shaft operation Figure 5.3 After modeling of the chamfers 5.3. Implementation of the trapezoid thread. Define a new Sketch in yz plane. Select the mentioned plane and run the Sketcher module. Then, change the name of the sketch to trapezoid outline (in the structure tree of the model - Properties - Feature Properties tab). The profile of the trapezoid outline will be implemented in twelve steps, which will be briefly presented: Just below the created rotary solid, we need to draw, using the Axis horizontal. tool, two lines: vertical and 14

Using the Intersection Point function located in the Point- menu, we generate the intersection point of these lines. The created point is of Standard type marked with a cross, we can change its appearance e.g. to more visible square or asterisk (Graphic Properties menu). If you generate this point correctly, then double Coincidence constraints should appear. Next, we scale the distances from this point to H axis and V axis in accordance with the figure 5.4. Figure 5.4 Stages of outline drawing step 2 and 3 Figure 5.5. Stages of outline drawing step 4 Figure 5.6. Stages of outline drawing steps 5.7 Draw a rectangle in the generated point using the Centered Rectangle function (figure 5.5). Delete the Horizontal constraints from the horizontal edges of the rectangle (marked with a red circle). This operation facilitates you to easily obtain the shape of a trapezoid by gently pulling the corner of the rectangle. Do that and in result you should get the profile with a shape as shown in figure 5.6. You also need to delete the Equidistance constraints (marked with blue circle), which are responsible for the symmetry of the vertical profile lines in respect to the vertical axis the designed trapezoid profile does not have this type of premises. Using the Intersection Point function located in Point menu, we generate the intersection points of the vertical axis and non-parallel sides of the trapezoid. The created points of Standard type are automatically visualized with a cross. In the figure, their appearance is changed to red square. If you generated the points properly, then each point should have double Coincidence constraints. 15

Using the Constraint tool we assign dimensions in accordance with figure 5.7. To create the fillet, you need to use the Corner Figure 5.7. Stages of outline drawing step 8 the vertical line using the Trim tool in both directions (figure 5.9). function. To implement the fillet on the right side of the profile (figure 5.8) in the Sketch Tools menu, you need to set Trim All Elements option and then you can created the fillets by editing the value of the radius and setting it to R= 1 mm. To create the fillets on the left side of the outline, you need to notice that they are located outside of the profile, and you need to extend Then, using the Corner function with Trim First Element, we create the fillets by editing the radius value and setting it to R= 0,5 mm. In this option, the order of lines selection while drawing is very important (the rest of the first clicked line disappears). You also need to delete unnecessary lines (marked in orange). The best way to do this is using Quick Trim tool with Break And Rubber In option, while selecting the unnecessary lines. Fully parameterized profile is shown in figure 5.11. Figure 5.8 Stages of outline drawing- step 9 Figure 5.9 Stages of outline drawing- step 10 Figure 5.10 Stages of outline drawing step 11 and 12 Then, you need to change the three points, which were created during Intersection Point operation - from standard to construction. The most convenient way is to do this while testing the profile with Sketch Analysis Mode tool. You need to highlight the mentioned points and using Set In Construction located in the Corrective Actions group, you implement changes of the mentioned point to construction. Prior to this operation, these points had the Isolated status, which made them unable to be used in the sketch. Close the analyzer window and exit the Sketcher using Exit workbench button. 16

Figure 5.11. Outline of the trapezoid thread Figure 5.12 Window of the sketch analyzer Figure 5.13 Starting point of the Helix The next stage of the work is to generate Helix type screw line. It s not possible in the Part Design module. Before the exiting, it s recommended to create a point that will become the beginning of the screw line. Use the Point function with Coordinates option in the Reference Element menu to create a point with coordinates shown in figure 5.13. Change the application to Wireframe and Surface Design (Start- Mechanical Design- Wireframe and Surface Design). Run Helix function, which is located beneath the Spline function. The parameters of screw curve must be entered to the window (figure 5.14), while as starting point you need to select previously created point and as axis you need to select V axis. Set the threat s pitch to 7 mm and height to 80 mm. Other parameters must be left default. Figure 5.14 Defining of the screw curve Figure 5.15. Generated screw curve Now, we have created all components for the implementation of the trapezoid thread. For this operation we must use Slot function with Pulling Direction option. Figure 5.16 shows the window of the Slot operation and the effect of its implementation. After the operation, an alert window will appear with information that in the notch there s a fragment with radius equal to zero, which is not possible to implement in the milling technology. 17

Figure 5.16 Window of the Slot operation and the effect of its implementation Save the file in your directory, but do not close it. Trapezoid profile of the thread will be needed in model of the screw. 6. Model of the screw Model of the jack s screw will be implemented using the method of base profile rotation. Open an empty file and in the structure tree name this part as screw. 6.1. Implementation of the screw s main part Define a new Sketch in the yz plane. Select the mentioned plane and run Sketch Using the Profile of Constraint tool. function. tool, you need to draw the profile shown in figure 6.1 and scale it with the help Figure 6.1 Profile of the screw s main part Figure 6.2 Model of the screw s main part Exit the Sketcher using Exit workbench button Using the Shaft tool implement the solid of the main part of the screw through rotating the profile by 360 0 angle in respect to the vertical axis - figure 6.2. 18

6.2. Implementation of the recesses in the top part of the screw Figure 6.3. Profile of the recesses in the screw s top part Define a new Sketch in the yz plane. Select the mentioned plane and run Sketch function. Implement the profile of recesses in the screw using Rectangular and Profile tool. Dimensioning of the profile must be carried out with the use of Constraint tool in accordance with the figure 6.3. Exit the Sketcher using Exit workbench button. With the use of the Groove tool, you need to make an undercut in the main part of jack s screw through rotating the created profile by 360 0 angle in respect to axis of the screw. Effect of this operation is shown in figure 6.4. In the obtained main part, we need to thicken the plug cooperating with the rod using ThickSurface tool. Select the cylindrical surface that you want to thicken. It s important to check whether the arrowhead direction of the thickening is correctly pointed outside you can change its direction using Reverse Direction button. Parameters of this operation, state during its implementation and the end result are shown in figure 6.5. Figure 6.4. Undercuts in the top part of the screw Figure 6.5 Implementation of the thickening in the top part of the screw 6.3. Implementation of hole for the rod Define a new Sketch in yz plane. Select the mentioned plane and run Sketch function. Implement the profile of the hole using Circle tool and scale it using Constraint tool in accordance with the figure 6.6. While drawing the circle, you must provide the Coincidence-type relation assigning the center point of the circle to V axis. 19

Exit the Sketcher using Exit workbench button. Using the Pocket tool, you need to make an opening in the screw s plug. In the following tabs: First Limit and Second Limit set Up to Next. The effect of this operation is shown in figure 6.7. Figure 6.6. Profile of the hole for the rod Figure 6.7 Finished hole for the rod 6.4 Implementation of chamfers and fillets for edges Dress-Up Features operations Using the Chamfer tool you need to make chamfers with dimension 1x45 o of the edges shown in figure 6.8. Change the color of the created surfaces to dark blue. Using the Edge Fillet tool implement the fillets of the edges presented in green with a radius of R = 1mm, and the edges presented in blue with a radius of R = 2mm. Change the color of created fillets in accordance with figure 6.9. Figure 6.8. Implementation of edges chamfers Figure 6.9. Implementation of fillets on the screw s edges Figure 6.10. Implementation of the chamfer on the bottom edge Using the Chamfer tool you need to create a chamfer with dimensions 4x45 o on the bottom edge of the screw. Change the color of created surface to dark blue. Chamfer Definition window and the end result of the operation are shown in figure 6.10. 20

6.5. Implementation of the thread in the jack s screw Trapezoidal thread of the Tr 42 x 7 screw will be created in a manner similar to model of the nut. We will use the profile of trapezoidal thread created in the nut model. Copy it and paste to yz plane in the screw model the easiest way is to do it in the structure tree ( trapezoidal profile Copy Paste). By double clicking on the copied Sketch - trapezoidal profile in the structure tree of the model, we can enter it to make the necessary modifications. The copied profile is shown in figure 6.11. Figure 6.11. Copied profile of the nut s thread a) b) Figure 6.12. Modification of the thread s profile The modifications include: Rotating it by 180 0 angle in respect to profile s vertical axis. You need to select the entire profile (without the symmetry axis, but necessarily with the constraints), then run Symmetry function and select the vertical dividing axis of the thread. The results of this operation are shown in figure 6.12a. Changing (from 10mm to 6.5mm) or assigning (17.2mm) the dimensions marked in red in figure 6.12b. The conducted modifications are necessary for precise configuration of the profile in respect to model of the screw. Exit the Sketcher using Exit workbench button. 21

Figure 6.13. Starting point of the Helix screw line Use the Point Element function - Coordinates option in the Reference menu to create a point with the coordinates presented in figure 6.13. This point will be a starting point for creation of the Helix screw line. Similarly as in the case of the nut, we need a Helix-type screw line to cut thread on the screw. Change the application to Wireframe and Surface Design (Start- Mechanical Design- Wireframe and Surface Design). Run Helix Figure 6.14 Implementation of the Helix screw line function, which is located beneath the Spline function. Parameters of the screw curve must be entered to the window (figure 6.14), while as the starting point we must select previously selected point and as the axis we must select axis V. Set the threat s pitch to 7 mm and height to 390 mm. Other parameters must be left default. After the implementation of the screw line, return to Part Design module by going to the top menu of the program: Start Mechanical Design - Part Design. Thread on the screw surface will be implemented using the method of cutting the thread profile along the screw line with the help of Slot tool. First, you must set the profile control method (Profile control - Pulling Direction) and as axis select screw s axis or V axis. As Profile you need to select trapezoidal outline of the thread and as Center curve you must select Helix screw line. Slot Definition window and notched screw are shown in figure 6.15. Figure 6.15 Implementation of the screw s thread Control of the thread output in the upper recess is very important. In the case of irregularities you need to correct the Helix s height preferably in the structure tree. 22

6.6. Implementation of the holes in the bottom part of the screw There are two holes in the bottom part of the screw. First is located in screw axis with M12 thread and is used to fix the safety washer. Second is a socket of the cylinder pin that protects this washer from loosening. To make the holes, we need to use the Hole tool. First hole must be implemented with options shown in figure 6.16. Run the Hole tool and select the surface of the screw s button around the planned hole. If we want to create a threaded hole, then we enter the parameters starting from the third tab - Thread Definition. This way some of the parameters in the first tab will be set automatically from the thread library. In the first tab in option Bottom, we can declare the shape of the hole s bottom. Operation of the holes implementation is shown in figure 6.17a. In option Positioning Sketch you need to definitely set the localization of the hole in the space. Figure 6.16. Implementation of the threaded hole in the bottom part of the screw a) b) c) Figure 6.17. Implementation of a M12 threaded hole in the bottom part of the screw Sketch in the Hole option fulfills positioning function and contains only Figure 6.18. Creation of the point the point visible as a white asterisk. In this case, it s best to use Coincidence constraints that are available in Constraints Defined In Dialog Box. We need to move the white point to the side, mark it along with the Origin point and enter Coincidence constraints asterisk changes its color to green which means that it has been clearly assigned. (figure 6.17b). Finished hole is shown in figure 6.17c. Second hole is for cylindrical pin and we implement it in such manner so there s no need for its positioning. First, we create a point on the bottom surface of the screw. Use Point function in the Reference Element 23

Figure 6.19. Parameters of the hole for the pin Figure 6.20. Bottom of the screw with holes menu with On Plane option. Enter coordinates of the point in Point Definition window as shown in figure 6.18. Highlight the created point, then run the Hole function and select bottom surface of the screw. Coordinates of the point will be assumed as conclusive location of the created point. In Hole Definition window, which will appear, set the diameter and depth of the hole (figure 6.19), in Type tab choose Countersunk type and the deepening parameters might be set as desired. Bottom of the screw with created holes is shown in figure 6.20. Save the file in your directory and close it. Figure 6.19. Parameters of the hole for the pin Figure 6.20. Bottom of the screw with holes 7. Model of the body Body of the screw jack will be designed as a die-cast element, reinforced with three ribs. Foundry slope value of the model walls should be assumed as 3 o. 7.1. Implementing central part of the body Figure 7.1 Profile of body s central part Figure 7.2 Solid of body s central part First stage in the construction of jack s body will be to create its central part, located between the base and the nut. Model of this body part will be implemented using method of base profile rotation around the jack s axis. Base profile must be implemented in the yz plane using the following sketcher tools: Profile, Constraint - Fig.7.1 (!angular dimensions must be created after the determination of the linear dimensions). Exit the Sketcher using Exit workbench button. Using the Shaft tool create the solid of the central part of the body through rotating the profile by 360 0 angle in respect to the vertical axis Fig.7.2. 24

Using Shell tool you need to choose the material from insides of the obtained solid, by setting thickness of the walls to 5mm and selecting front walls of the solid for removal marked in Fig.7.3. Figure 7.3 Model of body s central part 7.2. Implementation of socket for the nut Base profile of this part of the body must be implemented in yz plane in three steps: Figure 7.4. Implementation of the nut socket s profile step 1 Figure 7.5 Implementation of the nut socket s profile step 2 - step 1: drawing of the profile must be started by creating a line that will tie the implemented profile with already existing solid. This is done by projecting (using Project 3D Elements tool) body s top edge into the surface of the sketch (yellow horizontal line Fig.7.4). - step 2: using the Profile tool you need to draw the profile presented in Fig. 7.5, starting the drawing from the end point of yellow line and finishing on it (a Coincidencetype constraint should appear). The profile must close through the yellow line (yellow line constitutes the bottom edge of the profile). The profile must be dimensioned with the use of Constraint tool in accordance with figure 7.5. - step 3: using the Trim tool you need to cut the yellow line so that it will close the profile Fig. 7.6. Exit the Sketcher using Exit workbench button. Part of the body that constitutes the nut socket is implemented through rotating the base profile with the use of Shaft tool - Fig.7.7. Figure 7.6 Implementation of the nut socket s profile step 3 Figure 7.7 Part of the body that constitutes the nut socket 25

7.3. Implementation of the body base Base profile of the body base must be implemented in yz plane in the following steps: Figure 7.8. Profile of the body base step 1 Figure 7.9. Profile of the body base step 2 - step 1: drawing of the profile must be started by creating a line that will tie the implemented profile with already existing solid. This is done by projecting (using Project 3D Elements tool) body s bottom edge into the surface of the sketch (yellow horizontal line Fig.7.8). - step 2: using the Profile tool you need to draw the profile presented in Fig. 7.9, starting the drawing from the end point of yellow line and finishing on it (a Coincidence-type tie should appear). The profile must close through the yellow line (yellow line constitutes the top edge of the profile). - step 3: using the Constraint tool assign the dimension 4 mm between the starting point of yellow edge and vertical edge of the profile Fig.7.10. You also need to check, whether during drawing of the profile the contact constraints have been automatically assigned at both ends of the fillet arc. If not, then you must to assign them manually using the Contact Figure 7.10. Profile of the body base step 3 Constraint tool or Constraints Defined In Dialog Box - Tangency. - step 4: using the Trim tool you need to cut the yellow line so Figure 7.11. Profile of the body base step 4 that it will close the profile Fig. 7.11. - step 5: using the Constraint tool you need to assign the appropriate dimensions and change their values in accordance with Fig.7.12. Figure 7.12. Profile of the body base step 5 26

Exit the Sketcher using Exit workbench button. Model of the jack s base is implemented through rotating the base profile (Fig.7.12) by 360 0 angle in respect to axis of the jack, with the help of Shaft tool the end result is shown in Fig.7.13. After implementation of the base, you need to create a radius of R = 4 mm on the edge between the base and body of the lift using Edge Fillet tool Fig.7.14. Figure 7.13. Model of the lift s base Figure 7.14. Implementation of fillet for the base edge 7.4. Implementation of the ribs reinforcing the jack s body Figure 7.15. Profile of the rib reinforcing the lift s body Profile of the rib must be implemented in yz plane. Using the Line tool, you need to draw a line as shown in Fig.7.15. While drawing the line, you must make sure that the Coincidence-type relation is connecting its bottom end with axis H. The line does not have to enter into the material of the body. Then, using the Constraint tool, you must assign the dimensions in accordance with Fig.7.15. Exit the Sketcher using Exit workbench button. Model of the rib must be implemented using Stiffener tool by setting the thickness of the profile to value 8mm Fig.7.16 Figure 7.16. Implementation of the rib reinforcing the lift s body 27

Using the Edge Fillet tool, you must implement the fillets with a radius of R = 3 mm on the side edges of the rib walls. In order to do so, you must select the side walls of the rib (edges around the selected surface will light up in red). The program will create the fillets on all edges around these walls Fig.7.17. Figure 7.17. Fillet of the rib s side edges Figure 7.18. Circular Pattern window with entered parameters of the pattern Other reinforcing ribs will be implemented by copying the finished rib in a circular pattern with the use of the Circular Pattern tool. This function is located in Patterns menu, along with the Rectangular Pattern function. In order to enable the possibility of duplicating the rib with the fillets, it s necessary that they are loaded into the function when it is starting. To do this, you need to hold down the Ctrl button and then select a rib (stiffener), as well as the edge fillets in the structure tree of the model, and then turn on the Circular Pattern tool. In the dialog box, you must set the parameters in accordance with figure 7.18. As a reference surface, you must select the top surface of the lift s base. The ribs will be copied in the circular pattern with a spacing of 120 0. The model of completed jack s body was shown in figure 7.19. Figure 7.19. Completed model of jack s body 28