We live in a world of instant gratification. Rushing to find absolutes where they often don’t exist. And, when anxiously awaiting the arrival of something necessary, needed and game changing, like the Elio, we often forget that things most valuable to our existence take time.
Elio Motors continues to forge ahead with major developments. As noted on the timeline in the Elio Motors Tech Talk v4, (click here) one such development is the prototype kick-off for the engine block and cylinder head.
Elio Motors 3-Cylinder Block Program
IAV Automotive Engineering (click here), the power-train design and development engineering consultancy for Elio Motors, intends to produce engines using a high-pressure die casting process. To achieve this, IAV, together with Grainger & Worral (click here), will use their skilled expertise to design the prototyping process to replicate the design process for mass production.
Step 1: This process begins with the receipt of data from IAV. Best practices of manufacturing will be discussed to achieve the desired program timing and budget. While designing the tooling, IAV’s CAD model is checked for thin wall areas using specialized software. This activity is included in the design for manufacturability activities along with foundry processes including the addition of contraction, adding draft, removing undercuts and adding extra machining stock.
Step 2: As part of tooling, the gating and feeding system is to be designed for the casting. The introduction of the liquid metal into the mold cavity ultimately determines the integrity of the material and hence the functional life of a casting. The feeding system is used to ensure the last liquid metal to solidify is outside the net shape of the desired casting. Depending on the material properties required, chills can be used to enhance the properties of certain areas of the casting. For the 3-cylinder block this will be the cylinder bores and the bolt bosses.
First prototype Elio Motors 3-cylinder block raw casting
A few sample parts are poured and left until solid for the initial casting validation. After this process, the castings are knocked-out and the gating and feeding systems are removed. The castings are dressed with joint lines and any flash is removed. Castings are then heat treated and finally shot blast to clean and improve the appearance.
Step 3: The purpose of this final step of the process is to validate the material integrity and dimensional accuracy of the part. Using a CT scanner, 1 mm image slices are manipulated by a software program into a digital 3D model. This model is then overlaid to IAV’s machine CAD model and reviewed by a metrology engineer. Any deviation from the IAV model is highlighted and reviewed by the project team. This information is then relayed back to IAV via an inspection report.
During the development process, small modifications had to be made for the water jacket and the clamping feature locations for final machining. These were all common items needing detail during the design for manufacturing process.
What’s Next?
As you can see, the first prototype Elio Motors 3–cylinder block has been cast and is in the process of being shipped to IAV in Northville, MI. The next steps will be to take the raw casting and machine all of the specific Elio features.
Using companies like IAV and Grainger & Worral provide leading word-class design for manufacturing processes and features to ensure prototype parts will perform as designed. Stay tuned for an update on the Elio cylinder head in an upcoming Tech Talk.
First prototype Elio Motors 3-cylinder block raw casting -top view
