if you want to glue the piece that your cutting, you should use a router for a clean cut, althought a dremel will work. the drememl will be a pain in the *** though. what it does is melts the acrylic as its cutting, which in turn sends little pieces of burning plastic into your face. not the funnest thing, trust me i know!
ok i should have read the whople thing through be fore i started to reply. your not going to be ables to make a high strenght box by cutting the material with the dremel. your gluing\seaming sufaces need to be clean and smooth, which is nearly impossible to do with a dremel! i imagine your going to be using a standard cut off wheel right? the cut worth a damn! the wheels break like crazy so i hope you have alot of them! not to mention the burning plastic.
your best be for cutting is with a table saw, or even better, a router! as a matter of fact, your in my area. if youd'e like to come over and use my tools some weekend, ide be more than happy to let you use them. as long as its with me. (all my tools are company tools that i use for work every day)
so if you are going to use the dremel to cut the plastic, and then you plan on gluing up a box with it, you may consider doing it with silicone and not the acrylic solvent.
and by the way, you can find some good info at:
www.tapplastics.com
i think thats the site?