5 Top Tips for FDM 3D Printing

There is no doubt that 3D printing has grown in popularity in the last decade to become a term we are all familiar with. More specifically, within the design industry, the FDM 3D printing process has become an invaluable tool, saving time and removing risk from the design process.

Whether printing at home or using a professional service, like all processes, 3D printing has limitations and design constraints which should be considered before hitting the print button.

This post aims to outline 5 tips to ensure your part is accurate, cost effective and ultimately a success.

1. Minimise Overhangs

Most FDM machines are now sophisticated enough to print using a secondary support material. This material is either removed by hand or dissolved in a solution.

Although this means that we can print parts with overhangs, laying support material is an additional process for the 3D printer to complete. This means that parts with overhangs will usually require more material and machine time, ultimately resulting in a more expensive part.

Of course, there is many instances where overhangs are unavoidable, and this is the beauty of the 3D printing process. But if the part can be orientated to minimise the overhang, your bank balance will thank you for it.

OVERHANGS = COST

2. Use Fillets Much like the injection moulding process, using fillets is a simple yet effective method of increasing a parts strength. By adding fillets, we can minimise sharp corners and in turn, reduce the stress concentration at the intersection.

This simple addition to your designs means your part will be much stronger under force.

FILLETS = STRENGTH

3. Don't be afraid of post processing

One common constraint of the FDM 3D printing process is hole accuracy. Generally, holes print undersize, and the smaller the hole, the bigger the inaccuracy.

Because the level of this inaccuracy is hard to predict, it is difficult to adapt your design without 'designing blind'. Instead, we recommend designing holes slightly small and post process using a drill to ensure complete accuracy and hole definition.

HOLES = SMALL

4. Take care when scaling down

A common process when 3D printing models is scaling down. This is particularly common when 3D printing models where exact size is not important, such as model houses and floor plans.

However, when doing so, we must bare in mind that ALL model characteristics will be scaled down including wall thicknesses.

For example, if we have created a model house using a wall thickness of 5mm, but we want to print this 1/10th of the original size, this will make the walls just 0.5mm thick. In this case, it would be necessary to increase the thickness of the walls, to ensure a successful print.

WALLS = >1MM

5. Beware of tabs

Tabs and thin extrusions may be liable to breaking in FDM, especially if they are required to do work such as bend. We can minimise this by increasing the thickness of the tab and adding fillets. Furthermore, by orientating the tab in the horizontal plane on the printing bed, we can also increase the strength of the tabs.

You may wish to consider designing tab replacement into your model.

TABS = WEAK

We hope these simple but effective tips can help you create successful parts when using the 3D printing process.

Got some other useful tips when printing in FDM 3D printing? We welcome your comments.

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