Heatsynclabs is open even outside of the hours listed, I would check twitter, many of the members post on there when they are in the space.

When I still lived in Phoenix I would visit there often (I know many of the founders of HSL from the college I went to).

I haven't been there, so I haven't really gotten to know anyone there and I don't know their twitter, but I suppose I could try to Google something up. Have been wishing for something interesting on a weekend, though I've been really busy lately, too.