There are a few 3D Scanning Tips for part preparation for dark or reflective parts before you start: placing reference targets and coating the part.
Placing Reference Targets
For parts that have little geometry, place photogrammetric dots on the part in order to use these features during alignment.
Coating a Part
Reflective surfaces scatter the scanner light and create noise artifacts in the final data. Laser and white-light scanners do better when scanning matte, white surfaces. Developer, like Ardrox or magnaflux is a powder-based spray commonly used to create a flat white surface for scanning and is available at welding supply stores. Other products you can use include some athlete’s foot treatments, spray deodorant with titanium oxide, and tempera paint from a compressor. You can also use white spray paint if it is acceptable to create a more permanent coating.
You must spray the part with a uniform, light coat. The thinner the coating, the better. Adding more than a thin coat of developer can impact a part’s thickness when scanning. Developer comes off easily and is prone to fingerprints. Mounting an object to a surface (such as a bolt through the center of a threaded section) can provide a hand-hold for moving the part after spraying. You can also spray a portion of the part (leaving a section as a hand-hold), complete the first scan, clean the part, respray the area used as a hand-hold, and then rescan as needed. The following steps are a general procedure for applying developer to a part.
- Apply targets before spraying. Otherwise, the targets will slip off the white part.
- If necessary, mount the part or decide which section to use as a hand-hold.
- Hold the can 12 to 18 inches from the part and spray a light first coat.
- Set the object aside to dry for a few minutes.
- Re-spray any areas that need it.
- Clean any targets with a cotton swab prior to scanning if necessary.