Acrylic tubes, available in a wide range of colours and sizes, are easy to work with for all types of crafts projects. To cut your acrylic tubing clean and straight, the best option might be to use a table saw---but power saws are often quite expensive. A more affordable method for the do-it-yourselfer is to simply use a hacksaw with a fine blade. After making the cuts, file down the edges to clean them up.
Use a tape measure or ruler to measure the length of acrylic tubing you wish to cut. Mark the length on the tubing with a pencil.
Wrap some wide painter's tape around the tube so the outside edge lines up with your mark. The tape will serve as your cutting guide.
Set the tube into a bench vice, and tighten the vice so that it securely holds the tube.
Put on eye protection and a dust mask for your safety. You do not want to breathe in these particles. Put on a pair of leather work gloves as well.
Align your hacksaw blade with the outside edge of the tape on the tube.
Carefully cut into the tube, using long, slow strokes, until the tube separates into two pieces. Moving the saw too fast can heat up the blade too much, making a messy cut. It also can crack the acrylic.
Use a medium flat file or fine-grit sandpaper to smooth the cut edges of the tube.
Take your time, and make a few practice cuts on acrylic scraps. If you have a table saw, use a carbide-tip blade.
The table saw is a dangerous power tool; operate it only if you know exactly how to use it safely.