Fixing STLs

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Fixing stl files

stl stands for steroLithography, stl file format is an industry standard to print 3-D parts, and is the only file format that can be used at the Idea shop to 3-D print parts. stl file format contains only a surface of the 3-D part, unlike other common 3-D file formats that contain the texture, color, material properties and scale of the parts. In order for the printer to successfully print any part, the following features must be checked and fixed on Netfabb:

Number Of shells, holes, invalid orientations and border edges

When a part is opened on Netfabb, a pop up screen displays part name, part size and volume, number of triangles and shells, part quality, and finally scale factor. Any part that needs to be 3-D printed,must have just 1 shell per part, the number of triangles in a part varies depending on geometry and size of the part. A part must also have 0 holes, invalid orientations and border edges. Netfabb has a repair mode where it can create one continuous shell per part. The repair ( A RED PLUS ) icon is located to the right on toolbar, under repair a option tray will open up in the bottom left, then select "Automatic repair" , if that changes the number of shells to 1, Apply repair. Netfabb repair tool may or may not be able to fix all the features mentioned, in case it does not fix the features, go back to the software used to design the part and make changes there,double check on Netfabb, save the part and it is ready to be 3-D printed.

Surface thickness

NOTE: Surface thickness is check is only necessary for the z-printer, all the other 3-D printers are capable of printing parts one layer thick .i.e 0.025mm-0.30mm If your parts needs to be printed on the z-printer, then it is important to make sure that the minimum surface thickness is 2 mm, if the part is less than 2mm then there are high chances of your part breaking when you try to clean it. In order to check for part thickness, in Netfabb there is a icon for "new analysis", under new analysis select wall thickness analysis, in the pop up window change the wall thickness threshold to 2 mm, and let all other options be default and click OK. The part will be displayed with green color indicating thickness of more than 2 mm and red color representing thickness of less than 2 mm, if your part has any red color in it, its ideally not suitable to 3-D print on the z-printer as it will break when cleaning the parts. The only way to fix the part is by going back to the software used to design the part and change the necessary parameters there. Once the necessary changes have been made, recheck the parts for the features mentioned above, and if everything checks out, the part is now ready to be printed.