CREAT3D 3D printing tips: Desktop SLA 3D Printing Applications in Engineering
11 December 2017 | Sabina Gonzalez-George
Desktop SLA 3D Printing Applications in Engineering
This post was originally written in 2017 and has since been refreshed and republished for accuracy purposes.
The terms 3D Printing & Additive Manufacturing cover a huge breadth of technologies at varying levels, costs and accessibility, covering a broad range of materials, output and applications. In this blog, we focus on the use of SLA (Stereolithography) at desktop level for engineering applications, which produces parts with a combination of an excellent surface finish, level of detail and accuracy, at low cost.
What is SLA? What is Stereolithography?
SLA, or Stereolithography, is also known as vat photopolymerisation additive manufacturing. The SLA process is a light-based 3D printing process that builds individual layers of a model using a liquid polymer that is cured using a light source. Whilst the technology has been around since the 1980s, it’s development moved into the desktop sector from late 2010s onwards, with market leader Formlabs releasing their first SLA 3D printer.
What are the benefits of integrating SLA desktop technology?
Integrating 3D printers into your business bring a huge number of benefits; improving business workflows, faster turnaround times with rapid iterations, ability to improve design, increase sales, create alternative production methods, reduce product development time, enhance cross-team performance and sharing, and reduce costs, to name but a few.
In particular, the SLA process creates printed parts that have a smooth surface finish, with a high level of dimensional accuracy, tolerance and fine details, making SLA technology like the Formlabs Form 3 ideally suited to a range of engineering applications:
How is SLA technology used in Engineering?
Whilst the uses of SLA 3D printing technology cover a huge variety of applications, we have summarised how and why our clients are using and benefitting from bringing Form 3 and Form 3L 3D printers in-house:
Fine details on small prints are typically hard to print, but with the SLA process, positive and negative surface features can be produced to a fine level, even on small parts. For example, depending on the part geometry, with the Form 3, surface features are produced with a laser spot size of 140 microns.
Applications: Arts & Entertainment, Model Making, Jewellery Design, Dental, Assemblies, End Components
Smooth surface finish
With the SLA process, the 3D printed product has a very smooth surface finish, which can also be further sanded, polished or painted where required.
Applications: Electronics, Consumer Products, Medical Devices, Mould-making, Sales Models,
Tolerance, fit and repeatable accuracy are very important qualities, particularly for assemblies, end components and form, fit and function testing. SLA technology offers an excellent level of overall dimensional accuracy. For example, 95% of prints from the Form 3 were measured to within 240 μm or less (0.24 mm) of the designed dimension.
Applications: Form, fit & function testing, Medical Devices, Prototyping, Mechanical Assemblies
One key difference of SLA printed parts versus extrusion (also known as FFF or FDM) printed parts, is that the end print is solid (fully dense, rather than honeycombed), as the SLA process creates a chemical bond across layers in the polymer. Fully dense parts are water and air-tight and have consistent strength in all orientations, they also transmit and refract light (for example Formlabs Clear Resin can be used for visibility in structures, or prototyping of lenses)
Applications: Research & Development, Prototyping, Mechanical Engineering, Pneumatics, Microfluidics
Machining / Threading / Tapping / Moulding & Bonding
The range of post-processing applications that can be made to printed SLA parts is wide, due to their solid status; machining, threading, tapping, creating airtight connections, bonding, sanding, polishing, lubricating and moulding.
Applications: Automotive, Aerospace, Robotics, Contract Manufacturing & Engineering
Table 1: Machining operations with Formlabs SLA Resins, courtesy of Formlabs Inc.
Variety of materials
With the Form 3, you have the additional benefit of being able to use a wide range of resins, with different material properties, ranging from Standard Resins, through to Engineering range of High Temperature, Durable (printed part properties similar to polypropylene), Flexible and Tough (high tensile strength, with a flexural modulus similar to ABS). These materials vary significantly in tensile strength, elongation, and wear resistance, meaning they can be applied to a wide range of applications.
Best advice: Right technology for the right job
As 3D printing covers a huge array of technology, material and output, with an even broader range of applications, the best advice we at CREAT3D can offer is to choose the right tool for the right job.
There is no one size fits all solution, and each type of technology offers differing qualities, with different material options. As 3D printers are specialist equipment, in our experience we find that for many client applications a range of printer technologies and machines are required.
It all comes down to what you are trying to achieve, and that’s the best place to start with your decision.
Speak to a specialist. If you are looking for advice on which printer is going to deliver the best results for your needs, then contact the CREAT3D team and we can talk you through the options.