FAQ's & Help related to RP industry

Please check frequently asked questions related to CAD, CAM, RP & CNC Machining

What is preferred 3D Cad file format for cnc machining?
We prefer cad files in one of these formats:
  • PARASOLID (.x_t or .x_b)
  • STP or STEP (.stp or .step)
  • IGS or IGES (.igs or .iges)
Can you use STL file for machining?
Sorry, we cannot use STL file for machining. We can use STL file for viewing or quotation purpose but need 3d CAD file in Parasolid or STEP or IGES format for machining.
Can you use 2D file for machining?
Occasionally we may accept 2D files like Autocad .dwg or .dxf formats for 2D machining, routing or wire-cutting jobs but prefer to have 3d file.
Do you work in Millimeters or Inches?
MM (Millimeters).
What is CNC machining?
CNC, stands for Computer Numerical Control, applies to machine control system but erroneously used as a replacement term for NC. CNC is a generic term for vast field of numerical controllers. Our application is related to CNC Milling; used for machining complex parts and shapes hard to machine with conventional machines. Firstly cutter path is generated direct from the CAD model, which is transferred to machine controller in the form of numerical data. This data is used to move the machine table and tool to create the high precision jobs.
What are the Advantages of CNC machining?
  • No need to compromise with raw material because parts can be machined directly out of engineering plastics, ferrous or non ferrous metals.
  • Suitable for accurate and highly finished parts.
  • Economical for small to short run of production parts that require wide range of operations to be performed.
  • Generally large and bulky parts are economical by cnc machining compared to Rapid Prototyping processes because most of RP proprietary materials are expensive.
What are the Disadvantages of CNC machining?
  • Need to spend considerable time for programming before actual machining.
  • Sometime sharp corners are difficult to machined due to cutter radius which need to be sharpened by secondary operation.
  • Undercuts are difficult to machine so sometimes parts need to be made in sections and glued to accommodate undercut features.
  • Deep and narrow pockets/slots could be difficult to machine due to cutter size constrains.
What is your most common plastic material used for general purpose components?
ABS, (Acrylonitrite Butadine Styrene) is general purpose rigid Thermoplastic with a combination of properties that make it ideal for the widest range of applications.
What is suitable material for living-hinge featured components?
We normally use PP(Polypropylene) for living hinge parts. Check more detail on our Material related pages.
What is suitable material for clear transparent lens like parts?
  • Acrylic, also known as PMMA (PolyMethyl-MetaAcrylate) is an amorphous thermoplastic material with very good optical clarity.
  • PC (PolyCarbonate) can also be used for clear parts but clarity is bit lower than Acrylic. If you need combination of clarity and strength then Polycarbonate could be better choice.
  • Follow more detail on our Material related web pages.
What are the other materials do you use for machining?
PLASTICS: ABS, Polycarbonate(PC), Acrylic(PMMA), Acetal(POM), Nylon(PA6), GF Nylon, PP(Polypropylene), HDPE (High Density PolyEthylene), Teflon.
METALS: Aluminium 6061, Aluminium 5083, Brass, Mild Steel, Stainless Steel 304, SSteel 316, Tool Steel, Zinc, Copper.
Can we supply our own material for machining?
Sorry we are unable to use third party materials due to company policy.
What type of finishing available?
  • By default, parts are supplied with smooth finish i.e. outer visible faces lightly sanded to remove all machining marks but inner non-visual faces are left as a machined finish.
  • Following type of finishes available:
  • Standard finish: Also comes under the category of Smooth finish, suitable for visual presentation
  • Polish finish: Good for clear parts
  • Highly Polished finish: Good for master models
  • Primer Finish: Parts are Grey primed making them ready for painting
  • Painted Finish: We can match to your Pantone PMS colour code in Matt, Satin or Gloss finish.
  • Metallic Finish: Can paint in metallic finish in most common colours.
  • Tinting: We can tint on Clear or translucent parts
  • Chrome Plating: Yes we can Chrome plate on ABS plastic parts, works well for tapware and other metallic look parts
  • Anodising Finish: We can anodise Aluminium parts in most common colours.
  • Bead Blast: We generally use Bead Blast (Sand Blast) finish on metallic or translucent parts.
Do you have photos of different type of available finishes?
Do you have Pantone(PMS) colour chart available?
Yes, we have PMS chart available online but use with caution because colour matching may not be accurate due to monitor settings. Here's link Pantone PMS Chart
Who is cncprotos.com.au?
CNCProtos.com.au website belongs to an Australian based company Arptech Pty Ltd. This website is exclusively created to provide comprehensive information related to cnc machining service.
Do you provide any other Prototyping services?
Yes, we also provide following services:
  • FDM (Fused Deposition Modelling)
  • SLA (Stereolithography)
  • SLS (Selective Laser Sintering)
  • INJECTION MOULDING for Short run production, known as Bridge tooling.
  • Please visit our main site to get further information related to above mentioned services. www.arptech.com.au
Do you ship Internationally?
Absolutely, we are serving worldwide clients for more than a decade. We use FedEx, DHL, TNT for overseas shipments depends upon your preference.
We deliver what we promise, it's our commitment to you. Get Quote Now