3D Prototype Design Inc. was the first company in Canada to own and operate FDM 3D printing technology when it was introduced to the industry. After successfully offering and building numerous 3D printed parts for our customers, we added two more FDM machines to keep up with the demand.

Recognizing the need to provide customers with 3D prototypes that supplied better surface quality, improved strength and flexibility (in addition to building multiple pieces faster), 3D Prototype invested in Selective Laser Sintering (SLS) technology and retired their FDM machines.

As a result, we know a thing or two about FDM and SLS capabilities and the differences between the technologies, materials used and ultimately the quality of the final prototypes achieved.

Think You Want An ABS Part?

Many people interested in 3D printing an ABS part think they should make their part using FDM technology. After all, it’s the process that actually uses ABS material so it makes sense — or does it?

When we first offered ABS parts with FDM printing, we thought the same thing. But, when we gained our experience and knowledge with SLS and nylon parts we got some insight as to why this isn’t the case.

Yes, FDM builds parts in ABS material, however due to the nature of the process where one layer is placed on top of the next, the part doesn’t function the same as an injection molded ABS part (even though it’s made out of the desired material).

Here’s where it gets interesting…if you want an ABS part, you actually would be better off with a nylon 12 SLS part. Since the SLS printing process sinters (melts one layer into the next layer instead of laying one on top of the next), it actually creates prototypes that come closer to representing the characteristics and functionality of an injection molded ABS piece.

The Differences Between SLS & FDM 3D Printing

The easiest way to tell the different between the two processes is by comparing the flat surfaces of the 3D printed parts. SLS flat surfaces will have an even finish with a slight grainy consistency, whereas FDM flat surfaces will clearly show the extrusion lines where the material was deposited. While both offer durable materials, we do find SLS offers benefits that FDM technology cannot, such as building large multiple quantities at once, showcasing finer details and can be treated much the same as an injection molded part. For all these reasons and more, we moved away from FDM technology.

SLS 3D Printing Characteristics

SLS Printing Example

  • Builds .004 inches/.1016 mm layers
  • Fine nylon powder laser is melted one layer to the next
  • Powder is not lasered, but remains & acts as support, dusted away when build is complete
  • Solid plastic parts are produced
  • Can produce living hinges, functioning springs, snap fit, drill, tap & ready to assemble
  • Final parts have even surface finish as material originated in powder form
  • Building multiples in most cases

FDM 3D Printing Characteristics

FDM Printing Example

  • Builds .006 inches/0.1524 mm to .010/.254 mm
  • Uses ABS or polycarbonate plastic spooled material
  • Temperature-controlled heads extrude materials in layers, primary head and support material head. It draws the prototype similar to how a hot glue gun extrudes melted beads of glue.
  • Parts have some flexibility & functionality
  • Final prototypes show extruded line paths due to nature of the process
  • Often only builds one or a few parts at a time

If you’re unsure of whether SLS or FDM 3D printing is best for your project, please contact us for more information. Our 3D prototyping experts can help you decide which 3D printing technology will be most beneficial to your project.