3D printing speeds up tool and mould development
The design and development of tools in a traditional manufacturing setup, happen most of the time under uncertain circumstances. This results in either over-engineered tools and fixtures or underperforming ones. A few design iterations with actual tool builds could be useful for optimizing. But tool making is expensive with traditional manufacturing. So iterative tool building is not a viable option. 3D printing can speed up tool and mould development.
In tool design and manufacturing, there are always some tradeoffs. The tradeoff criteria include (a) performance, (b) lead time for development, and (c) cost. As the saying goes: “Good, Fast, and Cheap. Pick any two!”. This is the philosophy that traditional manufacturing works with.
Performance of a tool would depend on the following aspects:
- How effective is the tool?
- What is the quality of the output?
- Is it easy to use?
- What is the expected lifetime?
- Does the tool help to improve product cycle-time?
- Will cost of production improve by using the tool?
Lead time and Cost:
The following factors influence the lead time and cost for tool development.
- Available resources for design and development.
- Correct specifications on fits and tolerances. The internal communication process will determine how close to reality these figures are.
- Internal process standardization.
- The tool will manufacture how many parts? This will determine the material of construction, the ruggedness, etc.
- The assembly process. The location where the proposed part will join the main product. The preceding and succeeding processes also exert influences.
- Ability to perform in-process inspection or verification.
- The decision to make the tool in-house or get it made by an external tool maker.
- Availability of stock of required materials. Most of the times, fixtures and tools get made with available material which could be an overkill. This could help in machining costs or lead times. But it may also have a negative impact on the weight of such fixture or tool. In such cases, extra machining of the tool to reduce weight can increase costs.
- Traditional tool and fixture designs have to follow the rules of Design for Manufacturing (DFM) and Design for Assembly (DFA).This increases the number of parts in a typical tool or fixture. The cost and lead time of the tool go up as a result.
How does 3D printing change this scenario?
With 3D printing, it is possible to have all 3 – “Good, Cheap, and Fast!”. The tool can be good, inexpensive and have a short lead time. This is because 3D printing is able to provide the following benefits:
- The process is fast.
- It’s not bound by DFM or DFA. So there is more design freedom.
- The design can reduce the number of parts. There is no need for dowels and screws.
- The design-to-print methodology can help us to arrive at a near-final product without further machining or material removal.
- It is possible to use high temperature, high strength plastics for tooling.
- Complex shapes affecting the geometry and topology of the tool – such as bevels, pivot points and NURBS (non-uniform rational b-spline) surfaces can be included in the design.
- Different plastics such as hard, soft, conductive and elastic can be combined into a single design.The number of iterations of the design will not be a critical path for delaying the project. “Design-print” cycles can be really fast.
- The number of iterations of the design will not be a critical path for delaying the project. “Design-to-print” cycles can be really fast.
- Considerable weight reduction is possible without compromising structural integrity.