Echoing what
@ba-brewer said, 30min is too long for roasting a small batch of coffee. Something about your process is off, either you didn't give the roaster enough power, enough pre-heat time, or tried to roast too large of a batch. I don't know much about that roaster, but based on a quick look, i'm not sure that I would trust a single word from that website. For starters, you never want to "bake" coffee, baked coffee is bad coffee, it's considered a defect.
You didn't say anything about what your process was, so it's hard to say what might be going wrong, but here's some things that I would try:
* make sure the roaster is well pre-heated before you start (this goes for any roaster, i pre-heat my mill city for 30min or more before i roast)
* use smaller batches - i'd try in the neighborhood of 225g / 8oz, if that's around what you did, go smaller, like 125g
* do NOT go low and slow. Hot and fast is what you want, for small batches, like that roaster would be best at, look for 15 min or less, maybe much less
I got started with the information from sweet maria's, so that's the only place I can suggest to start. There's quite a few books out there, I haven't read any of them myself, but Scott Rao's books, particularly the recent "best practices" come highly recommended.