Strength and Fragility
Several factors make it hard to fully predict the outcome of the polishing process. One of them is the geometry of your part, which can act differently each time it is put in the tumbler. In general, you should have wall thicknesses of at least 1 mm throughout your part. Although we carefully place and orientate your parts in our printers to minimize “weak points” created by the layered buildup of your part, certain elements of your design may be more sensitive to the impacts of the polishing stones than others. Therefore, we suggest adding some extra wall thickness if your design can allow for it. Smoothing is not advised if your part has tiny details like pins because they are likely to break off during the polishing process. The largest dimension of your part should not be more than 200 mm, as bigger parts can get stuck during the smoothing process. The smallest dimension should not be less than 30 mm, as smaller parts can break in the process.
The small size of the polishing stones means that they can easily get stuck inside small holes. Therefore, we recommend that any openings which need polishing should be larger than 6.5 mm in diameter. This helps prevent stones from getting stuck inside your model. Also, note that the inside of your model will always be less polished than the outside. In fact, your part will not be polished at all on the inside if the holes are smaller than 6.5 mm because the stones will not be able to enter.
If your part contains sharp edges, these will be rounded off. Rounded corners and smooth transitions between surfaces will have a higher degree of polishing than sharp edges.
Embossed and Engraved Details
Embossed details on your model tend to be worn away by the polishing stones. Make sure to raise these details by at least 1 mm, otherwise they may disappear when your model is polished. Engraved details are less of a problem because, in most cases, the stones won’t be able to reach the inside of the engraving; however, the edges may still be affected. To be on the safe side, make sure your engravings are deeper than 1 mm.
We accept file formats STL, 3DS, 3DM, OBJ, WRL, MATPART, STP, SKP, SLDPRT, STEP, CATPART, IGES, MODEL, MXP, and MGX on Materialise OnSite.
Next to file formats we also have constraints related to the content of those files. To deliver the best possible quality and ensure traceability, we only allow 1 model per part to be ordered via our online platform OnSite. This means per file, there can only be one shell. If there are multiple shells in one file, we will only process it as it is recognized as one model or part meaning that the shells are intersecting or interlocking each other (if applicable see the technical specifications below). Otherwise your part will not be processed correctly.
|Standard lead time||Minimum of 10 working days, depending on part size, number of components and finishing degrees (online & offline orders)|
|Standard accuracy||±0.3% (with lower limit on ±0.3 mm)|
|Layer thickness||0.12 mm|
|Minimum wall thickness||1 mm, but living hinges are possible at 0.4 mm|
|Minimum detail||0.3 mm|
|Minimum clearance||0.6 mm between parts that need to be assembled
0.5 – 0.6 mm between shells of an interlocking part
|Maximum part dimensions||500 x 500 x 480 mm (online & offline orders)|
|Interlocking or enclosed parts?||Yes|
|Surface structure||Unfinished parts typically have a grainy surface but all kinds of fine finishes are possible. Polypropylene parts can be sandblasted, smoothed and painted.|