If you have been following our blog, you know about Formlabs which is a Massachusetts based company dealing with the manufacturing and development of desktop-based SLA 3D Printers. You might have heard of the Form 2 printer which was developed by Formlabs using Inverted Stereolithography or Inverted SLA methodology. They have done that again recently with the launch of Form 3 which is being touted as the Next Generation of Desktop 3D Printer with Industrial capabilities for which Formlabs has adopted a state-of-the-art Low Force Stereolithography (LFS) technology.

What is Low Force Stereolithography?

The basic idea that goes behind the development of this Low Force Stereolithography methodology is that the force exerted by the printer on the material during the printing process should be minimal. This methodology makes use of a flexible tank and linear illumination. This reduces the force used by the 3D Printer on parts resulting in better part detail as well as a better surface finish.

Apart from that, a completely new redesigned optics engine called Light Processing Unit (LPU) is used. LPU consists of a system of lenses and mirrors. This system helps in delivering accurate prints repeatedly. The LPU basically consists of a galvanometer which directs the positioning of a high-density laser beam towards the Y direction. Next, it makes the beam pass through a spatial filter and further towards a fold mirror and a parabolic mirror. This ensures consistent delivery of the beam perpendicular to the build plane.

Light Processing Unit (Source: Formlabs)

With the help of above technologies working in the backend, Low Force Stereolithography ensures production of flawless products in a rapid manner.

Watch this video by Formlabs to understand the working of this technology.


Low Force Stereolithography technology is an upgrade on Inverted SLA:

  • One major limitation faced during implementation of Inverted SLA is the exertion of significant force on the material during the printing process. This limitation is primarily tackled by LFS as discussed in the previous section of the article.
  • Another major problem faced by customers is that of Clean Part Removal. The LFS methodology is able to produce finer supports that are not supported by other SLA systems. This is done with the help of the flexible tank which is used in the system.
  • There are loads of improvements from previous versions such as easy of support removal, improvement in accuracy, more reliable, easy maintenance and support for large part printing, as well as advancement in special materials.
  • With technology, you can never be 100% sure as things can go wrong sometimes. What you can do is build your product in such a way that you can tackle all the problems. LFS uses Light Processing Unit with a resin tank, optical window and rollers. In a rare case that a fault arises in the product, these parts are easily replaceable. Apart from this, failure detection, as well as failure handling, has been improved so you can work and experiment without worry.
  • The technology of Low Force Stereolithography will allow businesses to manufacture large parts in their own premises with the added advantage of lower cost per part as well as faster turnaround time.

Applications and Future Scope of Low Force Stereolithography

Source: Formlabs

Low Force Stereolithography, with all of its innovations and developments, can be used to implement multiple functions.

  • We have mentioned fast turnaround time as one of the highlights of this technology. A practical example of this can be explained with the help of a jeweller’s case. A jeweller will be able to print around 150 rings in a single build. We can also take an example of a dental lab which can now produce and print around 40 dental arches in a single build.
  • Rapid Prototyping has been made easier and faster. With the use of a new material called Draft Resin, you can print large parts quickly and meet the accuracy needs of prototyping. With a layer thickness of 300 µm, it is three to four times faster than other standard resins and hence ideal for the process of rapid prototyping.
  • When we talk about future scope, we need to talk about growth. The scale at which technology can grow is very well thought of when technology is being developed initially. With the help of Light Processing Unit’s modular design, uniform linear illumination and other features, the LFS technology is built to scale up to a five times larger print area. So you can initially start with a single printer and as your business grows, you can bring in more printers together and integrate a network of machines.


This article about Formlab’s latest invention is important for all the companies or businesses dealing with 3D Printing SLA as well as others. It is important to note and appreciate the strides that they’re making with each new 3D Printer. I hope this article was worth your time. Do subscribe to our blogs for more content like this.

Learn more about stereolithography