A freelance engineer was retained by a major tool making company to create tools for a customer. The engineer was provided with digitized samples and point cloud data of a severely damaged component to create a 3D CAD model and technical drawing for manufacturing. The engineer then modified the model to make it suitable for die casting and designed moulding dies. Finally, the engineer created a process plan and simulated machining a prototype of the component in aluminum to optimize machining time.

1. Engineering Software – PTC Creo
School of Engineering
Computer Aided Engineering (Product
Realisation)
2
0
1
5
Luke Rumming
Course Code: ENG661, ID No. 667368
Lecturer: Dr Ivan Popov, Dr Alkistis Karabela.
Location: An 0.2
The target was imported into the PROE manufacturing by the
assemble reference model, and the work piece was then
merged. This identified the offsets needed to be machined.
Freelance engineer retained by a major tool making company. This
company is supposed to produce a tool for a customer.
For this purpose a severely damaged sample of the component (body) has
been digitised. A point cloud file is provided alongside with a picture of the
conceptual model.
Objectives are:
•Pick up the design concept from a digitised component and create a solid
3D CAD model and a 2D technical drawing for manufacture. Check the
model for accuracy.
•Modify the model in order to make it suitable for die-casting. Design a set
of moulding dies. Test the mold.
•Make a process plan and simulate the manufacture of a prototype of the
component in aluminium. Estimate and optimise the machining time.
Scenario
Reverse Engineering
Process plan and simulation
Mould Design
•Several damaged samples of a component (body) were digitised.
•A point cloud file has been chosen according to my last ID student
number; 667368.
•The independent geometry was then imported into the CAD system.
•Point tolerance and carve distance was set to 0.
•Datum points were created to constrain the point cloud in space,
enabling extrusion to take place.
The new model had to be within a ±0.05% tolerance of the original point
cloud.
The longest part of the model created is 125mm. The following
calculations were done in order to get the maximum allowable tolerance
in mm:
122mm x 0.005%=±0.625mm
A mould block 3x bigger than the part is constructed to insure the
mould will be able to withstand the pressures that injection
moulding puts on the work piece.
Mandrels were used to decrease the amount of waste material and
to form the bores of the valve and holes which are larger than
5mm. All mandrels have been draft to be extractable at the pull
direction.
Draft check tool was used to guarantee the mould parts and
mandrels are able to extract properly.
Roughing required a smaller
number of flutes (4) and lower
cutting speed. The tool being
used is a HSS End Mill.
The Finishing operations
followed the same path as the
roughing operations. However
more flutes were required, lower
step over, higher cut speed,
higher spindle speed, lower
tolerance and setting the profile
stock to zero. All these
parameters will ensure the
process will produce the most
accurate finish.