Some newbie questions

I'm considering building a RepRap, and I have some questions about where you can use it and such:

Where do people typically use their RepRap? Is it something you'd keep in the garage, or is it suitable to use in a home computer room?

How noisy is it? I live in a four unit building with attached garages, so I'd be concerned with it bothering my neighbors even if its kept in my garage.

I've read about people leaving it running unattended for long jobs. Are there any safety concerns with letting it run unattended?

If there are any other surprises or gotchas people have run into while building or using their RepRaps besides what I've asked about, I'd like hear those too. I'm really excited about the potential of RepRap, but I want to find out more about what I'd be getting into before diving in!

-Michael

The main gotcha is that if you buy and build it piecemeal like I have over the last year you'll find yourself a little frustrated with the fact that everything is moving so fast you'll be kicking yourself you didn't wait a couple of weeks to buy that part thats just been redesigned to be be easier/cheaper etc. :-)

From what I have heard from the online videos and also from testing my steppers, I would say that it is pretty loud.

That is pretty subjective though. If you had it in a garage I *doubt* it would annoy anyone.

In respect to long jobs, I figure the way you would do it was watch it a couple of times until you were convinced that its not going to spontaneously combust or explode and destroy the neighborhood. Then you could leave it alone for increasingly long periods of time.

-Mark

I live in an apartment myself and I've made more noise with the power tools to make the RepStrap cartesian system and nobody has said anything to me or seemed to notice at all and I know the motors on the actual machine are less noisy than what I was doing when I made it.
I don't know why it's so loud in all the videos, maybe the mic is just too close and doesn't like the frequency of the motor noise.
As for leaving it alone, we all have other things to do, but the main problem is the heater barrel. With some of the plastics, you have to heat it to 250C which is hot. As long as it's built properly and that section is safe, you're ok. Anything else that will mess up is maybe a belt coming off track and the part you are printing is messed up. The chances of more than that going wrong are about the same as any of your other electrical devices blowing up (as long as you took some precautions with the heater element).