When Corresponding Authors Don't Correspond
Authors, corresponding or otherwise, geneally do not respond for one of two reasons. The first is they miss the email. This could either be because of a wrong address, spam filtering, or a huge email backlog on their part. The other is that they do not think it is worth their while to respond. They could be so busy, that no matter how simple of a request, that they just are not going to respond.

Providing an explanation on how the nuts and bolts implementation works, is not an easy task. Providing a working implementation, can be even harder. Your want to make your request as easy as possible for them to (1) understand, and (2) address/answer. This means ideally asking yes/no questions where you provide enough background so they can see where you are coming from.