Problem with Repetier Host

export STL from SolidWorks

    File > Save As
    Set Save As Type to STL
    Options > Fine > OK
    Save
    STL settings: How to change STL settings
    File > Save As
    STL > Options
    For a smoother STL file, change the Resolution to Custom
    Change the deviation to 0.0005in (0.01 mm)
    Change the angle to 5 (Smaller deviations and angles will produce a smoother file, but the file size will get larger)

SolidWorks 2000 and later
Saving a model design in STL format

SolidWorks allows you to save model designs in STL format, at all levels of design, for both individual parts and assemblies, including the ability to save a multi-bodied model as a single STL. To save a model or a model assembly in STL Format:

    From the File menu, select Save as. The Save As dialog box opens.
    From the Save as type drop-down menu, select STL (*.stl).
    Click Options... The Export Options dialog box appears, and the model is displayed in tessellated view. STL is the File Format selection.
    In the Export Options dialog box, in the “Output as” section, select Binary. (The resulting file size will be much smaller than a file saved in ASCII format.)
    In the “Resolution” section, select the appropriate option. If you select Custom, you can manually adjust the Deviation and Angle settings, as needed. These settings affect the tessellation of non-planar surfaces, as follows:
        Lower Deviation settings result in finer tessellation.
        Lower Angle settings result in with greater accuracy, noticeable in small details.
        As a rule, the higher the resolution, the larger the size of the file, and the longer it takes to generate.
    For Single Material Builds Make sure that the following check box is selected: Save all components of an assembly in a single file. This ensures that all components are saved as a single STL file.
    For Dual Material Builds Make sure that the following check box is NOT selected: Save all components of an assembly in a single file. This ensures that all components are saved as separate STL files.
    Click OK.
    In the Save As dialog box, click Save.
    In the confirmation message, click Yes.