“You’ll see a closed loop manufacturing process, from CAD to printing to materials development. There will be a continuous workflow and everything will be refined.” Steve Immel -BD Manager, Materialise, USA
The intent here is to convey that adhering to certain tried and tested CAD design procedures help big time in attaining profitability of your finished sheet metal products.
In today’s competitive market, sheet metal fabricators’ efforts are in the direction to achieve collaboration between technology, people, processes, and supply chain across levels. Fabricators try to find a close loop between each stage from initial CAD design drafts to all the way through fabrication and back to designs.
‘Closed loop’, like other business jargons, too, have as many interpretation as the speaker and the audience. However, for sheet metal fabricators it is a very holistic concept; especially when designers try to adopt coherent fabrication processes right from designs. CAD fabrication drawings and the actual shop floor conditions vary extremely. This holds back the fabricators in achieving a seamless collaboration between designs and fabrication teams, but ends up with compromises in final products.
Challenge: A missing link between real world fabrication and ideal designs
CAD software environment is technically an ideal design world and the fabrication workshop is where the real world conditions come into picture. For example, while preparing designs, sheet metal design engineer may show an angle of 90° in fabrication drafts.
However, at times, it is impossible to achieve this due to wear of machine tool. This gap initiates change orders from shop floor and disrupts workflow which in turn breaks the closed loop system. The effects of ECO – Engineering Change Orders furthermore cause sheet metal fabricators to have cost overruns in order to meet stipulated deadline.
Apart from this, other barrier is when the sheet metal fabricator is compelled to deal only with a small part of a whole product, for example, designing a metal frame for a machine structure. Such issues occur at the time of assembly of the interfacing components. Additionally, there are extra efforts required to make the exchange a smooth process between contractors, suppliers and fabricators.
To design sheet metal products as per customized company rules, for efficient production stage, and to attain final products of highest quality; Design for Manufacturing guidelines are at the core of design needs. If design standards are not followed, it gives rise to an expensive hoax and trust issues between fabricator and contractor.
DFM: Design essentials for topnotch sheet metal end products
To attain final products of highest quality, fabricators look for a couple of valued propositions ingrained in 2D drafts and 3D CAD designs. Some of these include:
- Initial design drafts with design standards as per the fabricators’ target market
- Conceptual designs with DFM guidelines
- Refined finalized designs to attain functional prototypes
- A short-run manufacturing process
- Get the supply chain in place
To attain profitability from finished sheet metal products, implementing above mentioned steps is more than necessary. However, the initial step starts with accurate CAD drafting of sheet metal parts and components.
Keeping a quality check from right from design inception avoids last minute changes. Quality checks from start essentially ensure that conceptual designs and drafts fulfill all the product requirement and DFM guidelines. CAD drafting along with nesting drawings give comprehensive manufacturing information and avoids costly mistakes and keeps fabricators far from being wrong.
With an aim to avoid any ruckus, fabricators resort to more standard and reliable approach like CAD drafting of sheet metal fabrication with DFM strategy and design essentials that do not break the closure of the loop.
Digging deeper into CAD drafting
Once CAD drafts are accurately formed, annotated 3D CAD models with PMI and nesting drawings allow fabricator to understand the purpose of each and every element of design. Design engineers not having the right information of shop floor condition is probably the root cause of ECO, and nesting drawings prepared in collaboration with fabricators are the best way to address it. It prevents the fabricators on shop floor from running onto wrong path led by guess work and do not need to step away from production line asking questions to sheet metal design engineers.
To comprehend it even more efficiently and making a case in point; a sheet metal fabricator was able to save 50% of the manufacturing material during plasma & laser cutting using nesting drawings from CAD drafts. Besides, the fabricator could optimize the total fabrication time and future needs for modification was made easier due to CAD drafts.
Sheet metal product design engineers are empowered to inculcate design changes easily with editable CAD files and 3D models to evaluate the impact of design changes resulting from customer feedback. Flat patterns, cuts, bends, pattern parts, etc. can be easily made in the existing CAD models all before the product is actually manufactured. With high fabrication volumes on assembly lines, the smallest change in CAD drafts will affect the entire production line output; and in such scenarios, these features work to the advantage of sheet metal fabricator.
Starting from CAD draft, it goes all the way to designs, nesting drawings, manufacturing aids and finally accepting a feedback from customer; CAD thus forms a closed loop system. CAD goes on adding value to each step by receiving inputs from previously enhanced stage and finally gives a better product output with purpose built capacity. Once design procedure is aligned with fabrication, purchasing, procurement and costs can be streamlined, and big profits are on its way.