Years ago when in school I made a simple slot processor using sheets of acrylic I got from a plastics store and the appropriate cement, also from the plastics store. Other glues are unlikely to work. The cement is really a solvent, as described by Pieter12. The issue is, the solvent is methylene chloride, which is pretty nasty stuff. It won't kill you to look at it - it's not rat poison, but it is an irritant and carcinogen, and is more highly regulated now. In the US, TAP Plastics still sells it as acrylic cement but "for industrial use only." From the data sheet, Tensol 12 also contains methylene chloride. If you use it, use it outside, and if you have to dispose of the excess, do so in accordance with local waste regulations.