I have built several acrylic benders.
The basic ingredient is a channel in a piece of board lined with something non-flammable (I have used aluminium channel and fibreglass mat).
Put anchor screws at either end of the channel.
Hook a good strong tension spring on one anchor.
Run nichrome wire in a few loops between the other anchor and the free end of the spring, tight enough to keep good tension on the wire.
Use an adjustable power supply with alligator clips to apply power through the wire.
You can tune the setup by varying:
* number of runs of nichrome wire
* power supply current limit
* location of alligator clips on the wire
Andrew