Door Arm Rest Week 8 Challenge

DOOR ARM REST

The Class A surface is provided to us. We need to create B Surface and C Surface and create a solid model. At the end we have to do draft analysis to check whether the component is manufacturable or not.

Fig 1. Class A Surface

First of all we need to check whether the surface provided has any discontinuity in it. For that we will use the command boundary and check if there is any discontinuity in the surface.

After that we will join the whole surfaces by using join command.

Fig 2. Join Command

Then we will randomly select the tooling axis. For making the selection first analyse the shape of the product and avoid side cores as far as possible. Here we will take the Z axis as the tooling direction and mark a point there and create a datum axis at that point. We will make a dummy tooling axis in the Z direction. Here the side core cannot be avoided because there are ribs which are present on the side faces and this will not clear in the Z direction tooling axis. So we need to consider Side Core Tooling axis.

Fig 3. Dummy Tooling Axis

Next step is to take the intersect of the Class A Surface and the XZ plane.

Fig 4. Intersect in the XZ plane

Observe the surfaces which are parallel to the dummy tooling axes and which will create a problem while the component will be ejected from the mould. Draw a line through the surfaces.

Fig 5. Extending the surfaces which are parallel to the dummy tooling axis

Next bisect both the lines and obtain the line that is going in the direction of the dummy tooling axis. That will be the tooling axis in the XZ direction.

Fig 6. Bisecting the lines which are parallel to the dummy tooling axis

Fig 7. XZ Tooling Axis

Next obtain the tooling axis for the YZ direction by following the same steps.

Take the intersect of YZ plane. Identify the faces which are parallel to the dummy tooling axis.

Fig 8. YZ Tooling axis

Now we have got tolling axis in the XZ and YZ direction. Bisect both the lines and obtain the line which is in the direction of the dummy tooling axis. That is the required tooling axis.

Fig 9. Tooling Axis

Now we have to perform the draft analysis in the required tooling direction.

Fig 10. Draft analysis in the tooling direction.

When there are inner and outer holes or undercuts on the plastic part that are different from the mold opening direction usually a side core is used. Here also to clear the ribs we need to have a side core. So side core tooling axis is created and draft analysis is done in that direction.

Fig 11. Side Core Tooling Axis

Fig 12. Draft analysis done on the side core tooling axis

Now we have to create B Surface which is the Engineering Surface. All the features like holes embosses are created on the B Surface. For that we have to extract A surfaces, extend it and then trim it and apply the required fillets.

Fig 13. Class B Surface

Then we have to create C Surface. C surface is the surface which joins the A Surface with the B Surface. Extrapolate the A Surfaces and for the curved portions use Multi Section Surfaces to create surfaces. Join both A and C Surfaces.

Fig 14. Class A + C surface

Trim both the A + C Surface with the class B Surface. Then by using close surface command from the part workbench, turn the component into a Solid.

Fig 15. Solid Model

Draft analysis for the solid model on the tooling axis:

Fig 16. Draft analysis of the solid component in the tooling axis

Fig 17. Draft analysis of the solid component in the side core tooling axis

Some of the views of the solid model:

Fig 18. Isometric View

Fig 19. Top View

Fig 20. Front View

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