Abbreviations
CAD – computer aided design
CAM – computer aided manufacturing
CNC – computer(ised) numerical control
General
If you are not a CAD user, don’t worry. We can still read thumbnail sketches on the back of a fag packet! Hand drawn sketches can be scanned or even photographed with a phone if necessary, and emailed to us. PDF files are always great as an extra reference even if you are sending cad files, but these can be used on their own if not. We use Rhino3D for CAD modelling and RhinoCAM for CNC programming. Rhino3D is a very versatile CAD program which natively supports the following CAD and image file formats. Basically if you send us these, technically, we can open them. In practice, some are significantly better than others and it’s sometimes better to check first to save time.
DWG/DXF(AutoCAD 200x, 14, 13, and 12 )
IGS
STEP
SolidWorks SLDPRT and SLDASM,
SAT (ACIS, export only)
Microstation DGN
Direct X (X file format)
FBX
X_T (Parasolid, export only)
.3ds
LWO
STL
SLC
OBJ
AI
RIB
POV
UDO
VRML
CSV (export properties and hydrostatics)
BMP
TGA
uncompressed TIFF
VDA
GHS
GTS
KML
PLY
SketchUp
3D
If you have a 3D surface or solid model that is not a mesh file, it is better to send us this. We are able to machine from mesh files, but these can be less functional for us than a surface or solid model, and can lose definition which affects the quality of the surfaces. Rhino3D, IGS and Solidworks are great for us but we can also open a wide range of files detailed in the list above.
2D
You can save some of the cost of preparatory cad work by creating the layouts yourself. Geometry for two dimensional work is very straightforward, but mistakes with cad work can be time consuming and costly to correct. There are some simple things to watch out for which can help to avoid this.
- Overlapping lines: try to ensure that lines that are to be machined to have no overlapping sections, and are joined together.
- Curved (ie not straight) lines: make sure that the tolerance on curves is small enough not to create multiple straight sections.
- Profiles to be cut: these should be joined together as a continuous lines i.e. a rectangle should be a continuous joined together line, and not 4 seperate ones..
- Repeated components: ensure that there are no repeated sections of geometry superimposed on top of each other unless they are required, and denote different processes. If so, put them in seperate, clearly labelled layers.
- Sheet layout: There are many different sizes available, depending on the sheet material chosen. Common standard sizes for MDF include 2440×1220 and 3050×1220, but others are available. Check on the size supplied for your material, before laying out components for machining.
- Ask our advice about likely cutter diameters that will be used. This may vary depending on material, and size and intricacy of components. It will affect the spacing between components on the sheet layout.