Frequently Asked Questions

Should I use SLA or SLS for my prototype?

You need a prototype, and are thinking Additive manufacturing, but just not sure whether to go Stereolithography (SLA) or Selective Laser Sintering (SLS)?

Our simple to follow, light hearted step by step guide should help give you the basics…

SLSQ1 Toughness – what are you going to do with it?

This has to be the first decider! If you are planning on throwing your part around the office and your colleagues can’t catch, then we need to be thinking SLS! Parts made by SLS are typically nylon and hence tougher than the average SLA resin.

Years ago we built a 3 – 4mm wall section, box type part in SLS and I parked my car on it, to prove a point.

SLA resins continue to improve but they are generally not in this league.

Q2 Surface finish – rough or smooth?

On the presumption that we are not going to dress the parts as this always adds cost, and surface finish is important, then you need SLA.

SLS is like a course spark finish, SLA is closer to a moulded plastic part.

Q3 Clarity – do you need to see through it?SLA

SLS, no chance!

SLA, some resins are translucent and some are clear. To get the clarity you will need to polish/dress the ‘as built’ part.

Q4 Flexibility – hard or floppy?

SLS will allow you to build parts that bare a resemblance to TPE/rubber, whereas SLA works with hard materials. You will not get a range of hardness options (Shore A) but sometimes anything floppy is better than something hard!

Q5 Accuracy – how accurate is accurate?

These are all generalisations, but typically my money would be on SLA giving a more accurate part than SLS. Yes it depends on machine calibration and a host of other things but if you are in to measuring fractions of a mm then you want SLA

SLSQ6 I need something to test?

This is like the proverbial bit of string! It really depends on the test.

If you are checking IPXX, then accuracy of seal groves and quality of mating surfaces will be very important, go SLA.

If you are going to bolt it on a car and do 10,000km, go SLS.

If it's a temperature test, be careful! This can get geometry specific quite quickly. Some of the specialist SLA resins are good with temperature but ultimately it's the softening point that is your key combined with the service loads. (Note I ducked that one)

If it's a desktop product, either will suffice.

Q7 Cosmetics – exhibition models?SLA

SLS will usually take more time (hence cost) to dress to a cosmetic finish than an equivalent SLA part. Either will work, so perhaps the decider should be whether it’s going in a glass case or not!

Q8 Can I have hollow parts?

SLA requires support structures unless the part can be angled/designed to avoid them. As such access is required to remove them and this must be allowed for.

SLS uses the lose powder to perform this function, so as long as this can be shaken out there is less of a problem.

Q9 Do you need the parts yesterday or last week?

This is more about who you can find who has the capacity to do the job NOW!

SLS is a thermal process that requires the build to heat up and cool down – otherwise the parts distort like anything. However there are no supports so once cool the parts are almost instantly usable.

SLASLA requires supports but these can be constructed automatically and removed relatively quickly.

Possibly more importantly the economics of SLS require that the build is filled with parts, whereas SLA can run with a partial build. Hence SLS bureau's have to consolidate jobs to make the economics work.

Finally, it is possible to add parts to a running SLS build but not to an SLA build, useful if the train has just left the station…

Q10 Which do you want?

We all have a preference; sometimes instinct is the best guide!

Yes there is more, but this will point you in the right direction, if in doubt, just give us a ring or send your data to us at solutions@plunkettassociates.co.uk

 

  • “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

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

Stereolithography (SLA)

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

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