Week 9 - Attachment Feature Creation - Challenge 2
Creating Dog House, Screw Bosses on Coin Holder
Tooling Axis:
The tooling axis of the product tells us the direction of movement where the part is being produced effectively.
There are Some advantages if we follow the effective tooling axis like
The side cores and other things can be reduced.
Tooling axis has to be produced by considering some criteria’s like
- Direction of movement
- Bosses and other references have to be considered.
Creating Tooling axis by using CATIA V5:
The above image shows the different directions where the tooling axis possible to produce.
The tooling axis is not restricted to a particular direction. It can be produced in that direction where the product can be produced easily.
Bisecting method:
There are several ways to create a tooling axis, one of the methods is the Bisection method, where the line is created by bisecting the other lines and the point.
In the above picture, the tooling axis is created by using the bisecting method.
Step1:
The intersection is created directly in a sketch by using the intersection option, were created by simply using the intersection tool
Step 2:
The lines are drawn by taking the intersection lines are references. Just make sure to select the two points as a line type.
Step 3:
The two lines were drawn by simply selecting the two points.
Step 4:
The tooling axis is created by using the line tool, just make sure that to select the bisection option as a line type.
Step 5:
Bisecting lines are drawn by simply selecting the lines which are drawn above and the middle point.
Side Core Tooling Axis:
The side core tooling axis is used to show the movement of attachment and detachment of side core during the injection molding process.
There are several methods to follow:
On this side core, the tooling axis is generated by simply selecting the line and using the point direction.
In above green colored axis is the side core tooling axis
Screw bosses:
There are certain rules to follow to create the attachments like screw bosses and dog house.
Screw bosses:
Screw bosses are used as a guided way to the screw which is used to hold another component.
Screw bosses have to design in such a way that part could not be affected because of the screw bosses
Generally, the defects like heat shrink occur if the wall thickness is more.
To overcome these defects, we need to follow certain guild lines to construct the screw bosses.
Rules to follow:
- Draft - 0.5 degrees on walls of boss
- Thickness - Typically 40% of the nominal wall at the base.
- Height to Diameter Ratio - 3:1
- Radii - 0.25mm maximum radii.
Dog houses: these are the projections that are used to hold the screw bosses and other attachments.
These are used to overcome the defects which occur when the thickness of the wall getting increased because of the attachments.
Rules to follow (Dog house):
- Doghouse wall thickness at the intersection of the part wall (C) should be 40% or less than the main wall stock ( T ).
- Height of (B) should be between 3.0 – 6.0 mm
Draft angle: Usually draft angle is provided on the part, as well as the core and cavity, in order to reduce the wear and tear of the product while ejecting from the mold.
Draft analysis is nothing but the analyzing the draft angle provided on the part as well as the core and cavity of the injection mold by the Engineer
Draft angle allows ejector to simple push, to pop out the part from the mould
There are certain standards should be followed to provide the draft angle on the parts, core and cavity.
- Usually, the nominal draft angle 3deg is provided on the part
- Providing the nominal draft angle is easy and very economical.
Draft angle is depending on the material which is being used to prepare the product.
Ex: Textured parts required the more draft angle than the usual
Draft Angle Of 1 To 2 Deg:
There is a thumb rule that the part with a depth of 2 inches requires a draft angle of 1-2 deg for easy removal of the part.
Steps to Analyze the Draft:
Step 1:
To Analyze the draft angle first we need to turn on the draft analysis tool feature.
To turn on the draft analysis tool feature need to follow:
the above picture shown the way to turn the feature draft analysis.
If the draft analysis shown the error like wrong draw mode:
Needs to select the new material type which is there at the bottom with the question mark.
After selecting the new material, a pop-up is shown with several options, in those options needs to turn on the material type, and click ok.
After that, click the same feature draft analysis option which is available in insert.
Step 2:
Check the draft angle of the faces by clicking the options available on the tool bar.
The popup below the draft analysis toolbar shows the range of the draft angle of the face with the different colors.
From the above toolbar convey that the draft angle of the coin holder is above 3 deg so it shows in the green color.
The above toolbar shows the range of the draft angle of the Class-A surface.
If the Draft angle of the face is above 20 deg it shows the face color in red. If the draft angle is in between the 2-20deg it shows in sky blue color.
From these options, we can analyze the draft angle of the part surface.
