Sometimes when an .OBJ is imported into BINedit it will not import correctly, the faces may have collapsed or become scrambled and there may be many extra vertices. If you have trouble successfully converting various model formats to .OBJ for the purpose of importing into BINedit then consider the following:
If one converter does not do the job correctly then try another, results can vary from one format to the next and from one converter to the next.
When working on new models try saving them as different formats and then converting them to .OBJ using one or more conversion utilities.
Sometimes an .OBJ exported by certain modeling programs will not successfuly import into BINedit, try saving as a different format and then converting it.
If your model fails to convert then just keep trying different combinations of formats and converters until you find a successful combination.