Week 9 - Attachment Feature Creation (Ribs & Screw Boss) - Challenge 1
DOOR HANDLE - CLOSED SURFACE - ATTACHEMENT FEATURE CREATION - RIBS AND SCREW BOSSES
AIM:
To create a Door Handle Plastic Component using a Class 'A' Surface and by using the Closed Surface Feature to create a solid part from the surface and create a B Surface Attachement features Ribs and Screw Bosses.
OBJECTIVE:
- To Create a Plastic Component using the Class 'A' surface.
- To create a Tooling axis for a class 'A' Surface, which meeting the requirement of the draft angle and to analyse the solid model.
- To create a solid model from the surface using the Closed Surface Feature.
- To create a Attachement features Ribs and Screw Bosses on the created Class B Surface.
- To create a report which explains the Draft analysis and Tooling Axis cration - Bui secting Method and colour scale varient.
- To attach the screenshots of the expanded Tree Structure for the Geometrical Sets .
- To attach the screenshots of the 3D Part Model in different orientations.
PUBLICATION:
- Class 'A' Surface.
- Tooling Axis.
- Class 'B' Surface.
- Class 'C' Surface.
- Door Handle Solid Part.
INTRODUCTION:
TOOLING DIRECTION:
The Tooling Direction is the direction that the mold pulls apart. The mold is built in two separate pieces,
- A Cavity side and
- The Core side.
The Core pulls apart from the Cavity and that's the Dyeline or the Tooling Direction. The direction in which the mold or core and cavity opens is the tooling axis.
FEATURES OF TOOL:
- Cavity half – The cavity half is the side of a tool that does not move. It is typically attached to the side of the molding machine.
- Core half – The side of the tool that opens and closes with the mold machine against the cavity half. It opens when removing the part from the tool.
- Cooling lines – Channels that allow coolant to flow throughout the tool and control the cooling of the plastic part.
- Ejector system – Pins on the core half of the tool that helps push the cooled part out after molding.
- Runner – A flow path for the plastic resin allowing the press to inject material directly into the part cavity.
- Side actions – Moving pieces within the part cavity added to allow for undercuts.
CATIA 3-D SURFACE SOLID PART MODEL - CLOSED SURFACE FEATURE
CLASS 'A' SURFACE:
DESIGN CHECK:
The Class A Surface are Checked Visually by using the Join Feature or by using the boundary feature the Class A surface are selceted and Disassembled the Surface to check the surface are created without the gaps.
The Class A Surface should be created without the boundary Gaps. By using the Join Definition with the Merging distance of 0.001 mm the Class A surface are Joined Together to check the connectivity.
PUBLISHING THE CLASS A SURFACE:
By using the Publication option the Class A Surface are Published. The Publication is used to retrive the Class A surface in the easier way to use from the Structured Tree Implementation.
CREATING TOOLING AXIS:
The Tooling for the Class A Surface are Created in the direction in which the parts are getting Ejected from the Tool. The Tooling Axis which defines the core and cavity pulls apart from the Tooling Direction.
By uisng the EXtract feature definition the flat surface are selected and extracted .
By using the Point Definition, The point has been created on the circle midpoint.
The Reference Tooling Axis has been created using the line definition feature. From the line type point direction, Point has been selected and direction along z component are selected to define the line.
By using the Plane Definition the planes are created from the xy plane and moved through the point created from the origin.
By using the Intersection feature, the first element and second element are selected. The first Element Class A surface are selected and for the second element Plane are selected.
From the Intersection to the plane created. By using the line Definition, point - point type are selected and from the intersection Points, Line type 1 are created and another point - point lines are created.
The Two lines are created from the intersection, The lines are created which makes or slightly parallael to the Reference Tooling axis.
BI- SECTING METHOD:
By Using Line Type Bisecting, The Main Tooling Axis are created by selecting the Parallel Lines which are parallel to the tooling Axis. By Selecting the point as a support the Bi- Secting lines are created In- between Two parallem Lines. That line is the Main Tooling Axis.
The Bi- Secting Line divides a line into two equal halves. Thus, the perpendicular bisector of a line segment between lines, it implies: It divides two lines which are parallel/ slightly parallel to the Tooling Axis into two equal halves or bisects it.
MATERIAL MODES:
For the Draft Analysis, the material modes are Selected from the Shading Type.
DRAFT ANAYSIS:
For a Class A Surface, The Draft analysis are to be performed in order to meeting te requirement of the draft angle to the required Tooling Axis. For Plastic component the Minimum angle required for the daft to be 3 degrees.
The Direction compass are to be selected and placed it on the Main Tooling Axis line and the comass are been locked using the lock feature in te direction.
In the Display window the clour code varients are been selected, to know the range of the draft in the Class A surface. In the Display Window the colour varient shows,
- For 3 degeree - Green Colour Varient (Positive)
- For 0 degeree - Red colour varient.
- For Negative degeree- Blue colour Varient.
By Using the pointer feature in the Display the draft are been analysed for each individual points. The points perpendicular to the toling axis are displayed as 90 Degeree Direction and the Rib faces are analysed as 64.03 degeree angle.
The drafting are been performed in both the core and cavity side of Class A Surface. The Green colour Implies the draft angle are in the positive region. if The draft angle are been inverted the colour of the surface are imled as Blue colour.
For the given Class A Surface The draft analysis are been performed in order to determine whether the part aree cleared with the draft angle of 3 degeree. But with the given Class A Surface are not cleared with the 3 Degeree draft angle for the respective tooling direction. It will be cleared by 0.5 Degeree draft.
CREATION OF CLASS 'B' SURFACE:
By using the Class A Surface the Class B Surface are created by offsetting to the respective length to th respective direction. By using the offset surface definition the class A Surface are been offsetted to the length of 3 mm from the direction towards downward.
By uisng the Multi Section Surface creation the unfilled patches are been filled by selecting the respective guide curves and the guide spines.
By using the Joining feature the created patched area and the offsetted surface are been joined together to the merging distane of 0.001 mm.
By using the Extrapolate feature the Untrimmed surfaces are been extrapolated by selcting the boundaries and also the extrpolands. The continuty for the extrapolation are selected as curvature and propogation mode are been selected as point continuity. By selecting the features the boundaries are been extrapolated to the respective length provided.
CREATING CLASS 'C' SURFACE:
To make the Class C Surface, the Boundaries are been Extracted from the Class A Surface. The outer Boundary, are been extracted using the Bundary feature/' EXtract definitions.
By using the Sweep surface Creation definition, The respective profile type are been selected and subtype with draft direction are been selected. In that the Guide curve are selected as the. Boundary in the Class A Surface, and draft direction are selected as Tooling Direction with the draft angle of 3 degree are perforemed and the creation of Class C Surface.
By using the Join definition feature the created Class C Surfaces are been Joined together, and also by using the Extrapolation and Trimming feature the edges are been exttapolated and trimmed together to for the class C Surfaces.
The Class C Surfaces are been created by using the sweep feature and also the Direction along the Tooling direction and the reference with the surface and guide curve are been selected to form the Class C Surfaces.
By using the Join feature the Class A and Class C Surface are Joined Together with the Merging Distance of 0.001 mm.
The Final Trimming Has been performed on the Class B and Joined Class A and C surfaces. The Trimming has been performed.
CLOSED SURFACE:
By using the close surface definition the part surface are selected to make them into solid part from the part workbench.
DRAFT ANALYSIS:
The Draft Analysis has been performed on the Fianl component created as a closed body using the part design Closed Surface Feature. For Plastic component the Minimum angle required for the daft to be 3 degrees.
The Direction compass are to be selected and placed it on the Main Tooling Axis line and the comass are been locked using the lock feature in te direction.
In the Display window the clour code varients are been selected, to know the range of the draft in the Class A surface. In the Display Window the colour varient shows,
- For 3 degeree - Green Colour Varient (Positive)
- For 0 degeree - Red colour varient.
- For Negative degeree- Blue colour Varient.
By Using the pointer feature in the Display the draft are been analysed for each individual points. The points perpendicular to the toling axis are displayed as 90 Degeree Direction and the Rib faces are analysed as 6.89 degeree angle.
The drafting are been performed in both the core and cavity side of Class A Surface. The Green colour Implies the draft angle are in the positive region. if The draft angle are been inverted the colour of the surface are imled as Blue colour.
CREATING B SURFACE ATTACHMENT FEATURES RIBS AND SCREW BOSSES
CREATING RIBS ON B SURFACE:
The Door Handle surface are selected from the solid Surface and are extracted by selecting the elemets.
CALCULATION FOR THE RIB DESIGN:
As per the design rules the Ribes are been created, The Solid part for the Door Handle are been created with the thickness of 2.5 mm. For the Door Handle the Calculation are as follows,
(1). RIB LENGTH = `5*2.5 mm` `= 12.5 mm`
(2). RIB THICKNESS = `0.4*2.5 mm``=1.00 mm`
(3). RIB FILLET RADII = `0.25 mm`
(4). RIB DRAFT = `0.5 deg`
(5). RIN THICK @ TIP = `0.75 mm`
By using the positioned sketch the extracted surface are been selected and by using A Positioned Sketch the line has been created is a sketch that has its origin location or orientation defined with construction geometry. As the construction geometry changes the sketch position or orientation will change accordingly.
The Main tooling axis has been selected as projection point in which the defined point are selected based on the references. As per the design rules the Ribes rae created with the extruded length of 12.5 mm by calculating with respect to the thickness of the solid part.
By using the thickn feature the Extruded surface are been thickned to 1 mm as per the design rules.
By using the draft definition the fcaes are been selected in order to do the drafting on the faces of the ribs. Thre neutral elements are been selected as a extracted face and the pulling direction are been selected as a Main tolling direction.
The Boolean operation Union Trim are been performed on the created ribs and the faces to remove are been selected and the ribs are been formed in the solid part on the Class B surface.
The edge fillets are been performed as per the design rules 0.25 mm at the faces of the Ribs. The fillet operation are been performed.
RIB ROOT ANALYSIS:
Ribs should be designed to be 30-40 percent of the nominal wall thickness. Thinner does not provide much structure and may be hard to fill. Thicker ribs are tempting, but they can begin to introduce sinks on the cosmetic surface.
By using the plane definition the respective planes are been intersected into the middle of the ribs and also the elements are been selected to do the intersections on the plane surface. The Rib Root Thickness are been measured using the tritangent circle on the faces of the fillets and the bottom ssurface, the diameter of the root thickness are been measured as 2.686 mm, which is as per the design rules.
SCREW BOSS CREATION:
As per the design rules the Screw Bosses are been created, The Solid part for the Door Handle are been created with the thickness of 2.5 mm. For the Door Handle the Screw Boss Calculation are as follows,
(1). HEIGHT/DIA RATIO = `3:1`
(2). WALL THICKNESS = 40 % NOMINAL WALL @ BASE SIDES
(3). RIB FILLET RADII = `0.25 mm`
(4). WALL DRAFT = `0.5 deg`
By using the positioned sketch the Extracted surface are been selected and the screw circles are been drawn and the sketches are been Iso - constrained using the repective geometrical and dimensional constraints.
By using the Pad definition the 2 D sketch are been extruded to the respective lengths as per the design rule of screw bosses.
By using the Draft definition the inner and outer areas are been selected for the draft analysis and the neutral elements are been selected as the extracted elemet with respectto the pulling directions as main tooling directions.
For the Support for the Screw Bosses the Supporting Ribs are been added to the screw side faces. For that the supporting Rib sketch are been drawn and by using the pad definition the 2 D sketch are been extruded to the respective lengths.
The Boolean operation Union Trim are been performed on the created ribs and the faces to remove are been selected and the Screw Bosses with the supporting Ribs are been formed in the solid part on the Class B surface.
The screw with the supporting Rib profiles are bee selected and using the translate feature the anothr screws are bee created to the respective lengths.
By usig the Edge fillets the scre and supporting rib faces are been filleted to the respective radii 0.25 mm.
By using the plane definition the respective planes are been intersected into the middle of the ribs and also the elements are been selected to do the intersections on the plane surface. With the intersection the screw bosses with the supporting Ribs are designed and will validate with respect the design rules.
EXPANDED TREE STRUCTURE:
In CATIA the sketches and te surface operations are been defined using the Geometrical sets. By using the profiles like line, circle, hexagon, polygon, arc the 2 -D sketches are been created with reference to the Geometrical sets. According to the selection of plane from the possitioned sketch the 2-D sketch has drawn with the referene plane.
The surface opeartions like Extrude, extract, trim, split, edge fillets, surface untrim, sweep, smooth curves, extrapolating, Boundary and Fills are deined using te respective geometrical sets.
3 DIMENSION PART AND ORIENTATIONS:
ISOMETRIC VIEW, FRONT VIEW, SIDE VIEW AND BOTTOM VIEW:
CONCLUSION:
- The Door Handle Plastic Part Component using the Class 'A' surface are Created.
- The Tooling axis for a class 'A' Surface, which meeting the requirement of the draft angle are analysed and perfrmed.
- The solid model from the surface are created by using the Closed Surface Feature.
- To create a Attachement features Ribs and Screw Bosses on the created Class B Surface.
- The detailed report which explains the Draft analysis and Tooling Axis cration and colour scale varient are explained.
- The Class A, B and C surfaces are Published using the publication option.
- The expanded Tree Structure for the Geometrical Sets are explored .
- The expanded tree structure for part design are explored.
- The 3D part Model with various orientations are attached.