There are a handful of considerations and several advantages to keep in mind when selecting 3D printing as your custom manufacturing process.
There are two main price drivers to consider when pricing for 3D printed parts – material cost and machine run time. Understanding these factors and how to optimize them is important in lowering cost in all of the 3D printing processes Xometry offers: Selective Laser Sintering (SLS), Fused Deposition Modeling (FDM), Direct Metal Laser Sintering (DMLS), and PolyJet (PJ3D).
We’ve outlined our top five ways to save in 3D printing. Consider these suggestions when designing your 3D CAD file!
1. Reduce Z-height:
3D printers produce parts by successively layering material. For laser sintering processes, such as SLS and DMLS, the machines melt layers of powder. For extruding/jetting processes, the material is ejected through a printhead nozzle. For every layer, which varies from 0.001” – 0.013” depending on the process, there is a mechanical movement which can add a lot of time to a part’s build.
All things being equal, increasing the size of one of these layers tends to be faster and therefore less expensive than adding additional layers. For this reason, minimizing the vertical Z-height of the part is a great way to keep printing costs down. Sometimes splitting parts is also more economical than increasing height.
SLS, FDM, PJ3D, and DMLS processes all use printers with various maximum build platform sizes. These sizes are integrated into our auto-quoting algorithm, which means that parts that can be built lying on their side (horizontally) tend to be more cost-effective than those that have to be built with their longest face in the vertical direction.
Here are some good maximum lengths to keep in mind when designing your part for a particular process. Staying under these will generally ensure a lower priced part:
FDM: breaks at ~16”
SLS: breaks at ~12”
DMLS: break at ~4”
Seen here, a double cross-hatch pattern provides increased rigidity while retaining part strength
2. Reduce part volume:
Materials used in 3D printing processes, such as nylon powder (SLS) or rolls of thermoplastic filament (FDM) are a main cost factor. Thankfully, additive manufacturing processes are very efficient because printers can either recycle some unused material (e.g. non-melted nylon powder that acts as support structure in SLS) or produce minimal waste material (e.g. FDM cartridges that only extrude enough filament to make the part and support structure).
One way to limit volume, but still preserve overall dimensions, is lightweighting. Creating pockets in designs will reduce material usage, making it more cost-effective to build. When creating a pocket, be sure to create an exit hole for un-sintered (SLS and DMLS) or support (PolyJet) material removal.
For FDM printing, changing the infill is a great way to reduce part volume and cost. Xometry offers three different infill patterns for FDM:
Xometry’s Ultralight infill parts are filled with a single zig-zag pattern. This is the lightest and least expensive infill option.
Xometry’s Light infill parts are filled with a double cross-hatch pattern. This option provides increased rigidity and is lighter than a complete solid infill.
Xometry’s Solid infill parts are completely filled for the highest density. This is the heaviest and most expensive option.
Choosing the right material for your part can have a big impact on price
3. Choose the right process:
Different 3D printing processes have distinct price points. This means that choosing the right process for your application can be a great way to minimize costs
4. Test a feature before building the full part
This tip sounds straightforward, but is commonly overlooked. If you are interested in volume production, or a large or higher priced process, it often makes sense to design sample coupons that contain various iterations of features that will appear on your final design. Snap fits, interlocking geometries, all-in-one assemblies, and other features can all be designed with various offsets and sizes on a single test piece without having to order the entire part multiple times. For example, if a critical feature on a large part is a threaded hole we recommend just printing the thread to test how it mates before moving to the entire assembly. This will ultimately save calendar days and printing cost between prototypes.