Frequently asked questions
Short, citable answers to the questions we hear most often about 3D printing, SLS, materials, pricing and lead times.
54 questions
Cost & lead time
How much does a custom 3D print cost?
The price of a custom 3D print depends on the material, the part volume and the chosen finishing. SLS prints start at…
Read more →What makes up the price of an SLS 3D-printed part?
Four line items shape the price. Material (40-60% of the price, depending on polymer). Machine time (share of build time). Finishing (de-powdering…
Read more →Why does 3D printing get cheaper at higher volumes?
With SLS you spread the fixed costs per build (heat-up, cool-down, order overhead) across more parts. Larger runs share the same oven…
Read more →How do you reduce the cost of a 3D-printed part?
Four concrete actions. Shell solid volumes to 2 mm walls: 30-60% material saving. Bundle multiple orders into one build. Choose PA 950…
Read more →What is the break-even between 3D printing and injection molding?
The break-even usually sits between 1,000 and 10,000 pieces per year, depending on geometry and material. Below 1,000 SLS is almost always…
Read more →What does a small batch of plastic parts cost?
For 10-500 plastic parts the SLS per-piece price sits between €10 and €80, depending on volume, material and complexity. A small PA12…
Read more →Applications
When is industrial 3D printing worth it for businesses?
Industrial 3D printing is the right call once you need speed, flexibility or complex geometry. Think runs of 1 to 10,000 parts…
Read more →Which parts suit industrial 3D printing production?
Parts with complex geometry, run sizes up to 10,000 units per year or urgent lead time are a fit. Typical: brackets, enclosures,…
Read more →Can I have a broken or discontinued part reproduced?
Yes — Parts on Demand regularly reproduces replacement parts for machines, classic cars, white goods and industrial installations. Send us a STEP…
Read more →Is 3D printing suitable for production runs?
Yes — SLS 3D printing is industrially mature for production runs of 10 to 100,000+ parts per year. Parts on Demand runs…
Read more →Can a machine part be 3D printed?
Yes, provided it fits within SLS material and tolerance. Plastic machine parts (gears, brackets, cable management, housings, guides, air ducts) we print…
Read more →What is reverse engineering a spare part?
Reverse engineering turns a physical part into a production-ready 3D CAD file. We do this via 3D scanning (for complex geometry), calipers…
Read more →When is 3D printing good for jigs, fixtures and production tools?
Almost always. Jigs, fixtures and production tools are one of the most cost-effective SLS applications. You save CNC milling (hours to days)…
Read more →How do you prevent downtime with on-demand parts?
On-demand SLS production reduces downtime in two ways. Reactive: part breaks, replacement at you within 3-5 working days, no waiting for the…
Read more →Technology
Industrial vs hobby 3D printing: what’s the difference?
Industrial 3D printing delivers parts you can trust in production: 45-89 MPa tensile strength, isotropic, tolerance ±0.1-0.3 mm, batch traceability and certified…
Read more →What is SLS 3D printing and how does it work?
SLS (Selective Laser Sintering) is industrial 3D printing without moulds or milling. A laser fuses layers of plastic powder into your final…
Read more →How strong is an SLS-printed part?
SLS-printed parts in PA12 (PA2200) reach 45 MPa tensile strength and are nearly isotropic — strong in every load direction. Fibre-reinforced materials…
Read more →Why is SLS suited for functional parts?
SLS parts are isotropic, ~100% dense and hit 45 MPa (PA12) to 89 MPa (PA802CF) tensile strength. Materials are certified and traceable…
Read more →What are the advantages of SLS for industrial applications?
Four advantages. No tooling, lead time from 3 working days. Full design freedom (complex geometry, internal channels, integrated assemblies). Isotropic, predictable mechanical…
Read more →What are the limitations of SLS 3D printing?
Honest about the limits. Minimum wall ~0.8 mm. Tolerances ±0.1-0.3 mm (tighter needs CNC finishing). Surface lightly grainy (Ra 10-15 µm). Polymers…
Read more →What tolerances are achievable with SLS 3D printing?
Standard SLS tolerances at our shop: ±0.15 mm on dimensions up to 100 mm, ±0.2-0.3 mm on 100-300 mm, ±0.3-0.5 mm above.…
Read more →How dimensionally stable are SLS-printed parts?
SLS parts are dimensionally stable within ±0.15 mm up to 100 mm, and keep their size long-term. Provided they are not exposed…
Read more →Can an SLS part fit into an existing assembly?
Yes, provided you factor in SLS tolerance (±0.15-0.3 mm) in your design. For most industrial assemblies with fits H8/f7 or looser, SLS…
Read more →How reliable is SLS for repeat production?
Very reliable. Our SLS machines are closed thermal systems with controlled laser power, bed temperature and powder refresh. Print-to-print variation stays within…
Read more →When is a pilot batch worth running before production?
A pilot batch (20-100 pieces) is worth it when you consider: a new geometry for >500 pieces/year, a tolerance-critical fit, a sensitive…
Read more →Materials
What is the difference between PA11 and PA12?
PA11 and PA12 are both nylons used for SLS, but PA11 is bio-based (derived from castor oil) and tougher — with 31%…
Read more →What is the strongest 3D printing material?
For SLS 3D printing, PA802CF is the strongest material in our range: 89 MPa tensile strength thanks to carbon-fibre reinforcement in a…
Read more →Which 3D printing material fits technical parts?
Choose standard PA12 (PA2200) for most technical parts: 45 MPa tensile, isotropic, broadly applicable. For tough or bending parts PA11 (54 MPa,…
Read more →When should you choose PA12?
Choose PA12 (PA2200) for most industrial applications without specific requirements. 45 MPa tensile, isotropic, good dimensional stability, smooth surface. Suits prototypes, jigs,…
Read more →When should you choose PA11?
Choose PA11 when your part must withstand shocks, vibration or repeated flex without cracking. With 31% elongation at break, PA11 is considerably…
Read more →When should you choose Carbon LW (PA640GSL)?
Choose Carbon LW (PA640GSL) for parts that must not deflect under load. Glass- and carbon-fibre-reinforced SLS material, about 2x stiffer than standard…
Read more →When should you choose TPU Rubber-Like (TPU 1301)?
Choose TPU Rubber-Like (TPU 1301) for flexible, rubber-like parts: seals, dampers, grip zones, protective sleeves, gear rubbers or grippers for robot arms.…
Read more →Which 3D printing material is a good aluminium alternative?
For aluminium substitution in structural parts, PA802CF (89 MPa, carbon-fibre-reinforced PA11) and Carbon LW (56 MPa) are the best 3D printing alternatives.…
Read more →File & design
STEP vs STL: what is the difference?
STEP (.step) is a parametric CAD file that contains the exact geometry and feature history — ideal for production and machining. STL…
Read more →How do you design a part for SLS 3D printing?
For SLS you do not design like you would for CNC or injection moulding. No draft restrictions, no tool reach, no demoulding…
Read more →What is Design for Additive Manufacturing?
Design for Additive Manufacturing (DfAM) is designing so you exploit the benefits of 3D printing instead of copying classic restrictions. Use geometric…
Read more →What is the minimum wall thickness for SLS 3D printing?
For SLS, 1.0 mm is the minimum for non-loaded structures, 1.5-2.0 mm under mechanical load. Below 0.8 mm risks deformation or powder…
Read more →How do you prevent warping in SLS-printed parts?
Warping arises from thermal stress during cool-down, especially with large solid volumes or strong wall-thickness variations. Prevent it via uniform wall thickness…
Read more →How do you design snap-fits for SLS?
For reliable snap-fits use PA11: 31% elongation withstands repeated flex cycles far better than PA12. Design the snap lip at least 2…
Read more →How much clearance for moving 3D-printed parts?
For moving parts in SLS: 0.3-0.5 mm clearance. Enough to absorb SLS tolerance and let the part move smoothly after de-powdering. Precision…
Read more →How do you make a 3D-printed part stronger?
Four levers. Material: PA802CF (89 MPa) or Carbon LW (56 MPa, stiffer) instead of PA12 (45 MPa). Wall thickness up to 2…
Read more →How do you make a part lighter with 3D printing?
Three ways to make your part lighter. Shell solid volumes: solid to 2 mm walls saves 40-60% weight. Use lattice or topology-optimised…
Read more →What are common design mistakes on SLS parts?
Five classics. Walls under 0.8 mm (deform during print). Solid volumes >=10 cm³ without shelling (warping + high cost). Sharp internal corners…
Read more →Which file do you need for industrial 3D printing production?
STEP (.step) is the gold standard. Contains the exact parametric geometry we can modify. STL works too (mesh approximation) but gives less…
Read more →Can SolidWorks, Inventor or Fusion 360 files be used?
Yes, indirectly. Native files from SolidWorks (.sldprt), Inventor (.ipt) and Fusion 360 export to STEP (.step or .stp). All three packages support…
Read more →Why is my 3D file not production-ready?
Five classic causes. Not water-tight (open surfaces). Walls below 0.8 mm. Closed cavities without outflow. Wrong units (mm vs inch). Internal overlaps…
Read more →What happens in a manufacturability check?
A manufacturability check (DfAM check) is a free review by our engineers. They walk your CAD file for printability. Wall thickness, stress…
Read more →Comparison
When to choose 3D printing over traditional manufacturing?
Choose 3D printing over traditional manufacturing for runs below ~5,000 per year, complex or organic geometry, or when you cannot wait weeks…
Read more →Rapid prototyping vs production 3D printing: what’s the difference?
Rapid prototyping is one or a few parts with fast lead time, where iteration comes first. Production is tens to tens of…
Read more →When should you choose SLS over FDM?
Choose SLS over FDM as soon as you need functional, isotropic end-use parts, designs with overhangs or complex internal structures, or production…
Read more →Can 3D printing replace injection molding?
Up to roughly 1,000-5,000 units, SLS 3D printing replaces injection molding by saving €10,000-50,000+ in tooling cost and delivering in 3 working…
Read more →When is 3D printing cheaper than CNC machining?
3D printing (SLS) is cheaper than CNC machining for complex geometries, small runs up to roughly 100 parts, and designs with internal…
Read more →When should you choose SLS over SLA?
Choose SLS as soon as you need mechanical strength, toughness or higher temperature resistance. SLS PA12 hits 45 MPa, isotropic and tough.…
Read more →When should you choose SLS over MJF?
Choose SLS if you need a broader material range or higher strength. SLS runs 7 polymers (PA12 through fibre-reinforced Carbon LW and…
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