FDM 3D Printing Design Guidelines

Fused Deposition Modeling (FDM) 3D printing technology is the most widely accessible and commonly used form of 3D printing. It’s often used for modeling, prototyping and production applications. This additive manufacturing process layers material(s) from the bottom up by heating and extruding thermoplastic filament to produce a finished prototype.The system creates each prototype using layer upon layer in precise toolpaths that originated from the CAD file. After the model is completed, it is removed from the build chamber and the support material gets washed away.  

Through following these fused deposition modeling (FDM) 3D printing design guidelines your parts should come out as intended, but for additional questions and complex projects be sure to reach out to a member of our engineering team.  This video gives a great general overview about FDM 3D printing technology and what it can be used for.

 

 

Using FDM materials, you can guarantee specialized features and properties such as the following:

 Toughness

 Electrostatic dissipation 

 Translucency 

 Bio-compatibility 

 UV resistance 

 High heat deflection

These features allow FDM technology  to be flexible with working from a range of 3D printing applications and industries. The following materials make this possible.

FDM Materials

ULTEM 1010  ULTEM 9085  Nylon 12  Nylon 12CF  PC  PC-ISO  PC-ABS  ASA  ABSplus  ABS-M30  ABS-M30i

 

Please keep in mind that commercial grade material will automatically generate necessary supports. This allows for greater design freedom.There are many design considerations to factor in when manufacturing high-quality FDM parts. They are the following:

Corners – When printing with FDM, the nozzle is circular, so the radius of the printed models edges and corners will be the exact same size as the nozzle being used. Thus leading to not being able to assemble a perfectly square piece. When printing sharp edges and corners,the nozzle prints layer upon layer and compresses the material down to improve adhesion. This creates a flare and is usually called an ‘elephant’s foot’. The flare or ‘elephant’s foot’ impacts the ability to put together FDM parts outside the specified dimensions. There are other problems that often take place during the first print layer of FDM. Another one being, warping. Compared to PLA, ABS is more susceptible to warping because of its high temperature.  The first layer that is printed is the base. The base cools down as the other layers are printed on top. More times than not, this will cause differential cooling. It can also lead to the base layer curling up away from the build plate as it shrinks and contracts Something to consider is to include a 45 degree angle radius on all edges that come in contact with the build plate if the overall dimensions are critical to the function of an FDM part..

Hole Orientation –  Changing the print orientation can eliminate the need of support holes. You may find it challenging to remove support in the horizontal axis holes. However, moving the build direction by 90 degrees will get rid of support requirement. When working with components that include multiple holes in different directions, ensure the blind holes are prioritized. Later focus on holes including the smallest to largest diameter.

 

Feature	Description
Overhangs/Support	45 degree angle
Tolerance	±0.5%
Holes	0.2 mm
Supported Walls	0.8 mm
Unsupported Walls	0.8 mm
Pin Diameter	2 mm
Embossed/Engraved Details	0.6 mm wide  2 mm high
Connecting/Moving Parts	0.5 mm

 

Maximum Accuracy	0.089 mm or 0.038 mm/mm    0.0035” or 0.0015”/”
Layer Resolution	0.18 mm.-0.5 mm  0.005”-0.020”
Minimum Wall Thickness	1mm
Maximum Part Dimensions (single build)	914 x 610 x 914 mm (36 x 24 x 36 in.)
Finishes	Smoothing, painting, sanding

Single Contour Thickness

Slice thickness in. (mm)	Minimum wall in. (mm)
0.005 (0.13)	0.010 (0.26)
0.007 (0.18)	0.014 (0.36)
0.010 (0.25)	0.020 (0.50)
0.013 (0.33)	0.026 (0.66)

Produced FDM parts have the ability to withstand a great deal of post-manufacturing processes such as machining operations like drilling and tapping, sawing, turning, milling, smoothing, burnishing, sealing, joining, bonding, and plating. Keep in mind that heat is easily developed in plastic parts. If you remove the material using coolants and at a slow pace, it will keep the parts from distorting.