Before starting a new sheet metal fabrication project, you should have some idea of the design. This doesn't mean that you should know the precise specifications required for the final fabrication process. Instead, you want to have a rough idea of what the end product looks like and does, including specific features it should have and specific functions you want it to perform. Knowing this will help you conceptualize the end product and outline any dimensional constraints that your sheet metal fabricator should bear in mind during custom design. The following are factors to consider for the design process:

1. Enlist help from a professional during conceptualization

It is okay not to know exactly what you want; you're not the professional after all. However, rather than make uninformed assumptions during conceptualization, enlist the help of an experienced metal fabricator. Explain what you want the best way you can – you can also show him/her where the product will be used so that he/she can better visualize what you need. They will then be able to advise you on required functionality, maximum and minimum lengths, flexibility, durability, cost and other design considerations.

2. Ask for a CAD prototype

Once you have the preliminary configuration details for your custom design, your metal fabricator feeds it into CAD software, in order to create a three-dimensional model of the product or part. You can also get two-dimensional schematics which will help you to properly visualize your end product prior to manufacture. The CAD prototype can show you what you think you want, so that you can determine whether or not it works. Any issues can be corrected at this early stage before work starts.

3. Determine degree of tolerance needed

Different custom projects demand different tolerance levels; precision sheet fabrication has very small tolerance for error and the fabrication process must be precise. Broader tolerance means that the fabricator can employ cheaper production methods which give end products much faster. You can reduce costs and ensure safety by maintaining tight tolerance on essential/potentially hazardous features and allowing wider tolerance for the dispensable features/functions of the part.

4. Assess the first-run product

If your custom project requires metal assembly, you will need to evaluate the first product of manufacture. This will give you a full idea of how weld fasteners and seams would look like, which could come out different from what you saw in the drawings or CAD outputs. Any differences can be addressed e.g. changing the hardware used or adjusting weld parameters. If necessary, another product can be built to confirm the function before the final run. At this stage, the fabricator will also configure tools to the right setting according to the design dimensions.

Bonus tip: weighing costs

You should determine before the project starts whether the end-product will need more hardware or assembly before being shipped. Weighing costs early in the project will ensure you don't run out of resources mid-project by allowing you to make allowances for everything. Also, determine the batch quantities which in turn affect raw material selection, tooling and design optimization to minimize total project cost.

For more information on metal fabrication, talk to a professional.