It should be possible to convert 3D models saved as .a3d files (Amapi 3D) to other 3D modeling formats, including 3ds Max graphics (.3ds). You will probably have to rely on some dedicated 3D conversion utilities like 3D Object Converter, or similar to sucessfuly convert your 3d model from A3D to 3DS format.
Convert Amapi 3D modeling data to 3ds Max (3D Studio MAX) graphics.
We have found one software suitable in our database for this conversion.
Microsoft Windows software - convert a3d to 3ds on Windows
3D Object Converter is a powerful 3D polygon model translation and interactive viewing shareware tool that allows arbitrary 3D model data to be imported from external sources, exported to various industry standard 3D file formats with great accuracy and quality.
Convert from a3d file
to 3ds file
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.