Design a printed part around the test you need to run. A presentation model, a working latch and a shop fixture may need different materials, print orientations and finishes. Decide which features need to look right, carry a load or fit a mating part before choosing the process.
Plan for the way the part is built
SLA uses cured resin and often needs support contact on some surfaces. Mark cosmetic areas and allow access for cleaning and curing. In FDM, the layer direction can affect strength. Discuss how the part should be oriented for the main load and where supports can be removed.
Allow access to remove powder and supports
SLS and MJF build parts in a powder bed. The surrounding powder supports many shapes during printing, but trapped powder still needs a way out. Review openings and cleaning access for enclosed cavities and internal channels. In a design with a movable joint, check both clearance and the route for removing powder.
Example: a sensor enclosure with a sliding lid
Consider a small sensor enclosure with a sliding lid, guide rails and an internal cable passage. The lid needs to slide smoothly after finishing, and the passage needs to be clear before wiring.
- FDM: Orient the housing so the rails can be printed cleanly. Keep supports reachable so they can be removed without leaving ridges on the sliding faces.
- SLA: Where possible, place support contacts away from the mating faces. Give uncured resin and wash fluid a path out of the cable passage.
- SLS or MJF: Give the passage accessible openings for powder removal. Review how powder will be cleared from the rail grooves and check that the passage is clean before fitting the cable.
Print short samples of the mating rail and lid at several candidate clearances using the planned material, build orientation and finish. Measure the mating widths and try each fit after cleanup. Confirm the chosen clearance on a full-size enclosure before ordering the batch.
Validate the features that need to work
Mark thin walls, clips and other details that may be sensitive to the selected material or build orientation. Specify mating dimensions and check them with a test print before ordering a batch. If a bore or mounting face needs a tighter fit, discuss finishing or machining it after printing.
Explore the 3D printing process options and SLS for functional nylon parts.
