Understanding Print Settings When Ordering Parts: FDM and Resin parts

When ordering parts either using our online ordering tool or by contacting us, you will need specify a couple of settings based on your requirements.

The very first and probably the most important thing is to choose the material for your parts. This will depend on your requirements and you can use our materials page to help you choose. If in doubt, don't hesitate to contact us directly.

Once you have decided on the material, there are couple of settings you need to decide on to order your parts. This article aims to provide a quick overview of what these settings mean.

FDM Printing

For FDM printing you have two options to select - thickness and infill.

Thickness and Infill settings in our instant ordering tool.

1. Thickness (a.k.a Layer Height): The Balance Between Detail and Speed

FDM printers build parts by depositing thin layers of plastic. The thickness or layer height is the height of each of these individual layers.

Depending on the material you are using, we have two thickness options:

• 200 microns (0.2mm) - Available for all materials

  • This is by far the most common thickness setting.

  • At this setting layer lines are usually visible

  • This is optimal for print time and overall part cost.

    
    

• 100 microns (0.1mm) - Available for selected materials only

  • At this layer height individual layer lines are not usually visible unless you are looking very closely. This makes it a better option for parts where surface finish is the primary consideration.

  • Downside of smaller layer height is the significantly increased print time and cost as the printer has to print double the number of layers.

Our recommended thickness setting is 200 microns for most parts as it is provides good balance between cost and print quality.

You may also come across layer height of 300 microns being used in the industry. Traditionally this has helped to reduce print time and cost. However, we find that with modern printers going from 0.2mm layer height to 0.3mm does not really reduce printing time or cost, but has a potential to reduce part strength.

2. Infill: How Strong Do You Need It?

Your FDM 3D printed part is generally not 100% solid plastic on the inside. Instead, it's printed with an internal latticework called "infill". The infill density refers to how dense this internal structure is.

• 20% Infill - Low strength

  • Best for: Most non-functional prototypes, visual models, and parts that don't need to withstand significant stress.

  • Benefits: Faster printing, uses less material (more cost-effective)

  • Expectation: OK structural integrity for general use.

• 50% Infill - Stronger, More Durable Parts

  • Best for: Functional prototypes, mechanical components, and parts that will experience moderate loads or stress.

  • Benefits: Significantly increased strength and rigidity compared to 20% infill.

  • Expectation: Much more robust, but uses more material and takes longer to print.

• 80% Infill - Maximum Strength & Rigidity

  • Best for: High-stress functional parts, jigs, fixtures, and components that require near-solid strength.

  • Benefits: Close to maximum strength an FDM part can achieve.

  • Expectation: Very strong and heavy, but the longest print time and highest material usage.

Comparison of 20%, 50% and 80% infill.

Resin (SLA) Prints

Resin 3D printing builds parts by curing liquid resin with light, resulting in incredibly high detail and smooth surfaces. The technology is fundamentally different from FDM, leading to different setting considerations.

All our resins have been optimised to give the best quality parts and are printed at 50 micron layer height.

For resin prints, infill works differently to FDM. Parts with thin walls and sections are generally printed solid.

However, for parts with thick sections it is often better to hollow out the part to improve print quality and reduce material usage. This is a manual process and also requires adding small holes into the part to allow for airflow during printing and allow all uncured resin to be removed from the part during post processing.

Cross section of a hollowed out part with internal infill as well as a "vent hole".

Choosing What's Right For You

Understanding these settings empowers you to better communicate your needs to us.

Don't worry about being an expert – that's our job! We deliver high quality 3D printed parts and knowing your requirements will help us do that.

Do you have parts that you need 3D printed? Contact our Coventry team for a consultation or upload your model for a free quote.