WYNTEK WIKI
THE MANUFACTURING WIKI
Plain-English reference for 3D printing and CNC machining: how the processes work, what the materials can take, which files to send, and the design rules that decide whether a part works. Figures are typical values from the datasheets and references cited on each page.
Processes
How each manufacturing process works and what it is good for.
FDM 3D PrintingFDM (fused deposition modeling) is a 3D printing process that builds a part by melting thermoplastic filament and laying it down through a heated nozzle, one thin layer at a time. It is a low-cost way to make functional plastic prototypes, jigs, and enclosures in materials such as PLA, PETG, ABS, and nylon.SLA 3D PrintingSLA (stereolithography) is a 3D printing process that builds parts from liquid photopolymer resin, hardening each thin layer with ultraviolet light. It produces smoother surfaces and finer detail than FDM, and printed parts are washed, and usually post-cured, before use.CNC MachiningCNC machining is a subtractive process: computer-controlled cutting tools remove material from a solid block until only the part remains. For prototypes and small batches it usually means CNC milling, where a spinning cutter follows programmed toolpaths through a clamped block of metal such as aluminium or steel.
Materials
Properties, strengths, and limits of the materials we build with.
PETGPETG (polyethylene terephthalate glycol) is a tough, slightly flexible thermoplastic used in FDM 3D printing. It prints almost as easily as PLA but handles more heat, impact, and moisture, which makes it a default choice for functional prototypes.PLAPLA (polylactic acid) is a stiff, low-cost thermoplastic made from fermented plant starch, and the most widely used material in FDM 3D printing. It prints accurately and holds fine detail, but it is brittle and softens at about 55 to 60 °C (131 to 140 °F).ABSABS (acrylonitrile butadiene styrene) is a tough, amorphous thermoplastic used in FDM 3D printing and in moulded products such as LEGO bricks. It handles more heat and impact than PLA or PETG, but it warps as it cools and prints best in an enclosed, heated printer.NylonNylon (polyamide) is a family of tough, wear-resistant thermoplastics used in FDM 3D printing for clips, hinges, and parts that slide or flex. It stretches a long way before breaking, but it absorbs water from the air, which makes it harder to print and changes its stiffness in use.Standard resinStandard resin is a general-purpose liquid photopolymer that SLA 3D printers cure into solid parts, one thin layer at a time, using light. It gives smooth surfaces and fine detail, but cured parts are brittle and have a heat deflection temperature of about 71 to 73 °C (160 to 163 °F).6061 Aluminium6061 is a heat-treatable aluminium alloy strengthened with magnesium and silicon, and one of the most common aluminium alloys for general-purpose use (in the US it is called 6061 aluminum). In the T6 temper it reaches a tensile strength of about 310 MPa (45 ksi) at roughly a third of the density of steel.Steel for CNC MachiningSteel is iron alloyed with carbon, and it is the choice for machined parts that need more strength, hardness, or wear resistance than aluminium can give. Common machining grades run from low-carbon 1018 and medium-carbon 1045 to 304 and 316 stainless steels, which resist corrosion but are slower to cut.
File formats
Which CAD and mesh files to export, and why it matters.
STL FileAn STL file is a 3D model saved as a mesh of triangles that describes only the outer surface of an object. It is the de facto standard file for 3D printing, but it stores no units, colour, or design history, so the export settings decide how good the file is.STEP FileA STEP file is a neutral CAD file, defined by the international standard ISO 10303, that stores a part's exact solid geometry so it can move between different CAD and CAM programs. It is the preferred format for CNC machining because it keeps true curves, flat faces, and units instead of approximating them with triangles.3MF FileA 3MF file is an open 3D printing format, published by the 3MF Consortium and standardised as ISO/IEC 25422:2025, that packages a model's triangle mesh together with its units, colours, materials, and other build data in a single compressed file. It was designed to close STL's gaps: a 3MF file states its unit and must describe closed, consistently oriented geometry.OBJ FileAn OBJ file is a plain-text 3D model format, first developed by Wavefront Technologies, that describes an object's surface as vertices and polygon faces, with optional normals and texture coordinates. Colours and textures live in a companion MTL file, and the format stores no units.
Design rules
Walls, tolerances, supports, and settings that decide if a part works.
Wall ThicknessWall thickness is the distance between the two faces of a wall in a part. Practical minimums are about 1 mm for FDM printing, 0.2 mm for SLA resin printing, and 0.8 mm for machined metal, and walls that carry load should be thicker.Tolerances and FitsA tolerance is the amount a dimension may vary from its nominal size and still be acceptable, such as 10 mm ±0.1 mm. A fit is the designed relationship between two mating parts: a clearance fit lets them move, an interference fit makes them grip, and a transition fit sits between the two.Overhangs and SupportsAn overhang is any part of a model that extends outward over empty space, and supports are temporary structures printed beneath it so it does not sag or fail. In FDM printing, surfaces that lean up to about 45 degrees from vertical usually print without supports.Infill and Layer HeightInfill is the internal structure printed inside an FDM part, and layer height is the thickness of each printed layer. Together they set much of a print's weight, surface, and print time, but walls and orientation usually matter more for strength.
Reference
Definitions of the terms used across 3D printing and CNC machining.
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