Frequently Asked Questions

When is Stereolithography the better option?

Many years ago, Stereolithography (SLA) was the rapid prototyping solution, accurate, fast, relatively stable unless you can remember the acrylic based resins, and easy to paint. It was the dream master pattern for the vacuum casting process and could even be used as an investment casting pattern.SLA

Then along came laser sintering (SLS), worse surface finish, less accurate (usually), often slower due to the required cool down times (or it warped!), a real pain to use in vacuum casting and totally the wrong material to go anywhere near investment casting. (You had to run polystyrene to do this)

Come up to date and whereas the request was “please quote SLA” the most common request we hear today is “please quote SLS”, so what happened and are people missing out?

SLS provides functionality testing

What SLS brought to the game was a level of functionality that an SLA user could only dream about, working predominantly in Nylon 12 these parts could take some serious abuse. In fact, so much abuse that we were constantly trying to come up with ways to demonstrate the potential. We dropped them, we parked my car on some, and then we built panels for a Smart car and drove it around. Up to this point the only alternative would have been to use a Stereolithography master and vacuum cast it in polyurethane, a combination that would have doubled the lead time. Against this the negatives were insignificant; parts could now be used.SLS

Of course, the other differences were no supports and a consequence of this, the ability to pack parts in three dimensions rather than two. Both of these offered a potential economic advantage that led to SLS being generally regarded as the most cost-effective prototyping option.

So, given functionality and a better price why is Stereolithography still around? Well for vacuum casting that is easy to answer, the finish is far better suited to moulding form. For prototypes the clue is in the materials, these have not stood still, and whilst there may be a general acceptance that Nylon 12 will out function Stereolithography resins, there is another objective hidden here and that is one of simulation.

SLA produces accurate parts with an excellent surface finish

It remains that a massive reason to prototype is to confirm the design integrity before going to tooling, a high value long lead item that can be compromised by changes. To achieve this accuracy is clearly important, but so are the tactile senses - does it look and feel right? This is why in resin marketing we see phrases like “the look and feel of an injection moulding”.

This creates a different objective, that Stereolithography is well placed to fulfil. This is about simulating injection mouldings, about accuracy, appearance and yes functionality but only to a threshold and not absolute. Mouldings utilise snap fits and self-tapping screws for example and clearly these must also work. We have to be able to handle and assemble the parts without fear of breakage too, but is it necessary to drop it on the floor? If the material is not the production material what is this going to tell us?SLA ClearVue

The logical follow on question is “well what if it was the production material?” With the ever-increasing process speed this is starting to happen, material properties are there for some applications and will no doubt continue to progress. There is also much work going into post processing of all additive parts, methods of colouring and improving the surface finish of SLS being some of the most dramatic.

Economics and price

The other issue was economics or price, and this brings some surprises, SLS is not always the cheaper option. This is geometry and resin specific but there are increasing cases of Stereolithography offering a very competitive price point to SLS.

There is no ‘one answer fits all’ but in this particular tussle its worth stopping to ask, ‘what am I really trying to achieve’ and at least explore the options. There are other processes out there that also deserve consideration and the optimum choice will only come from a wide understanding of the pros and cons of each, for example, where should DLS or FDM fit in this? 

Understanding your objectives

It is for this reason that Plunkett Associates will often ask for more information, to try and better understand your objectives rather than just quoting what you ask for. It’s not that we know better, it’s just that there may be another option out there!

PS Before you ask, the Stereolithograhy resin alluded to that has given us such good results is from DSM and is called Somos EvoLVe 128 – a data sheet can be found here

  • “Plunkett Associates have excellent breadth of experience, work with high quality partners and have a flexibility that we have found enables challenges to be met successfully, cost effectively and in a timely manner.”
    Nick Skaer, CEO, Orthox Ltd
  • Plunkett associates always find a solution. Whatever we need to prototype, they have a great grasp on the technologies available, costs and lead-times so we get the right solution tailored to the project needs. Have always delivered and never let us down.
    Naim Audio
  • “I can’t recommend Tim and his team highly enough. We ended up with a design which can be produced and assembled quickly, efficiently and reliably, in volumes that make sense”
    Simon Leggett, Director, Olivewood Technology
  • "Tim's experience, expertise and supplier base have been fundamental to us getting this project off the ground."
    Sam Pearce, Jelly Products Ltd
  • “We were really surprised at how quickly they turned round such a high quality prototype and the parts certainly proved their worth. They were of high enough quality to provide a fantastic visual representation and to undergo rigorous testing."
    Stuart Wilson, Design Director, TRT Lighting
  • “Accuracy, finish and delivery all first class.”
    Andrew Peters, JMDA Ltd
  • “We use Plunkett Associates because we want someone we can trust, that knows what they’re talking about, has all the contacts, will provide reliable advice and feedback and will get the right result for us.”
    Jim Copestick. Design Manager, Thorlux Lighting
  • “We always know exactly what we’re getting and we know we won’t be let down on quality, price or lead times.”
    Mark Williams, Research and Development Director, Johnson Safety Products
  • “Plunkett Associates truly offer a complete turnkey solution with Speed, Effectiveness and Precision.”
    David Harden, Director, Enica Ltd
  • “Kirintec were thrilled with Plunketts. They made a complex process simple and we were just amazed at the lead times achieved. Plus, every single deadline was met without any drama.”
    Penny While, Marketing Director, Kirintec
  • “Thanks to Plunkett Associates flexible, bespoke and cost effective service I was able to produce the objects that I had originally had in mind.”
    Simon Ryder, Artist
  • To create such a consistent quality finish in chrome was an amazing achievement and the prototypes really gave our stand the wow factor.
    James Clark, Group Commercial Director, The Airdri Group
  • Interestingly, people who look at it in its own right with little knowledge of what it does, just like it! It’s tactile and it looks good…
    Tim Collings, Operations Director, Troika Systems Ltd
  • "With their simple to understand language, willingness to go the extra mile and approachability, Plunkett Associates were a great partner for our company. We couldn’t be happier with the results of our project. (A working prototype that they got right first time, by the way). Thank you!"
    Carolina Ballon-Forrester, Director, Kittyrama Ltd
  • Plunkett Associates worked on the design and production of titanium frames for an artificial heart valve where precision and consistency was paramount. Communications were efficient and productive with concepts readily incorporated into the final design, and suggestions for improvements all highly appropriate. The quality of the end product was ideal and I have no doubt that I will use the advice and expertise of Plunkett Associates again.
    David Wheatley, Wheatley Research Ltd
  • “Thanks for the present that arrived this morning, as promised. Parts look first class, as always.”
    Jon Todd, Design Manager, PHS Group
  • “Plunkett Associates have a fantastic supply chain, work with all sorts of production processes and will always do their utmost to solve a problem.”
    Naim Audio
  • “ Plunketts developed a solution that met our precision requirements at a cost significantly lower than alternative manufacturing approaches we had investigated”
    Nick Skaer, CEO, Orthox Ltd
  • “Doing business with you has been an absolute pleasure. You have made my goals a reality. You have been patient, helpful and above all, responsive. Best service that I have experienced in ages. I consider Plunkett Associates to be an integral part of my business plan moving forward.”
    Jet Cooper, Sculptor
Related Processes

Stereolithography (SLA)

Produces accurate 3D models with a range of material choices. High Res SLA and Micro SLA for smaller parts.

more info

Selective Laser Sintering (SLS)

Selective Laser Sintering (SLS) is the second most commonly used process after Stereolithography (SLA). SLS parts can be produced with high functionality in very short lead times.

more info

Read more expert articles in our FAQ section where we discuss topics on materials, methods and products.

Back to FAQs
  • “Plunkett Associates have excellent breadth of experience, work with high quality partners and have a flexibility that we have found enables challenges to be met successfully, cost effectively and in a timely manner.”
    Nick Skaer, CEO, Orthox Ltd
    Nick Skaer, CEO, Orthox Ltd
  • Plunkett associates always find a solution. Whatever we need to prototype, they have a great grasp on the technologies available, costs and lead-times so we get the right solution tailored to the project needs. Have always delivered and never let us down.
    Naim Audio
    Naim Audio
  • “I can’t recommend Tim and his team highly enough. We ended up with a design which can be produced and assembled quickly, efficiently and reliably, in volumes that make sense”
    Simon Leggett, Director, Olivewood Technology
    Simon Leggett, Director,  Olivewood Technology
  • "Tim's experience, expertise and supplier base have been fundamental to us getting this project off the ground."
    Sam Pearce, Jelly Products Ltd
    Sam Pearce, Jelly Products Ltd
  • “We were really surprised at how quickly they turned round such a high quality prototype and the parts certainly proved their worth. They were of high enough quality to provide a fantastic visual representation and to undergo rigorous testing."
    Stuart Wilson, Design Director, TRT Lighting
    Stuart Wilson, Design Director, TRT Lighting
  • “Accuracy, finish and delivery all first class.”
    Andrew Peters, JMDA Ltd
    Andrew Peters, JMDA Ltd
  • “We use Plunkett Associates because we want someone we can trust, that knows what they’re talking about, has all the contacts, will provide reliable advice and feedback and will get the right result for us.”
    Jim Copestick. Design Manager, Thorlux Lighting
    Jim Copestick. Design Manager, Thorlux Lighting
  • “We always know exactly what we’re getting and we know we won’t be let down on quality, price or lead times.”
    Mark Williams, Research and Development Director, Johnson Safety Products
    Mark Williams, Research and Development Director, Johnson Safety Products
  • “Plunkett Associates truly offer a complete turnkey solution with Speed, Effectiveness and Precision.”
    David Harden, Director, Enica Ltd
    David Harden, Director, Enica Ltd
  • “Kirintec were thrilled with Plunketts. They made a complex process simple and we were just amazed at the lead times achieved. Plus, every single deadline was met without any drama.”
    Penny While, Marketing Director, Kirintec
    Penny While, Marketing Director, Kirintec
  • “Thanks to Plunkett Associates flexible, bespoke and cost effective service I was able to produce the objects that I had originally had in mind.”
    Simon Ryder, Artist
    Simon Ryder, Artist
  • To create such a consistent quality finish in chrome was an amazing achievement and the prototypes really gave our stand the wow factor.
    James Clark, Group Commercial Director, The Airdri Group
    James Clark, Group Commercial Director, The Airdri Group
  • Interestingly, people who look at it in its own right with little knowledge of what it does, just like it! It’s tactile and it looks good…
    Tim Collings, Operations Director, Troika Systems Ltd
    Tim Collings, Operations Director, Troika Systems Ltd
  • "With their simple to understand language, willingness to go the extra mile and approachability, Plunkett Associates were a great partner for our company. We couldn’t be happier with the results of our project. (A working prototype that they got right first time, by the way). Thank you!"
    Carolina Ballon-Forrester, Director, Kittyrama Ltd
    Carolina Ballon-Forrester, Director, Kittyrama Ltd
  • Plunkett Associates worked on the design and production of titanium frames for an artificial heart valve where precision and consistency was paramount. Communications were efficient and productive with concepts readily incorporated into the final design, and suggestions for improvements all highly appropriate. The quality of the end product was ideal and I have no doubt that I will use the advice and expertise of Plunkett Associates again.
    David Wheatley, Wheatley Research Ltd
    David Wheatley, Wheatley Research Ltd
  • “Thanks for the present that arrived this morning, as promised. Parts look first class, as always.”
    Jon Todd, Design Manager, PHS Group
    Jon Todd, Design Manager, PHS Group
  • “Plunkett Associates have a fantastic supply chain, work with all sorts of production processes and will always do their utmost to solve a problem.”
    Naim Audio
    Naim Audio
  • “ Plunketts developed a solution that met our precision requirements at a cost significantly lower than alternative manufacturing approaches we had investigated”
    Nick Skaer, CEO, Orthox Ltd
    Nick Skaer, CEO, Orthox Ltd
  • “Doing business with you has been an absolute pleasure. You have made my goals a reality. You have been patient, helpful and above all, responsive. Best service that I have experienced in ages. I consider Plunkett Associates to be an integral part of my business plan moving forward.”
    Jet Cooper, Sculptor
    Jet Cooper, Sculptor