This device enables one to hold the elastic for the headband with one hand; freeing the other hand to make holes in it and cut it to the required length.
The roll of elasticated material passes through the device and is held by two grippers.
I use a soldering iron to make the (elongated ) holes and to seal the ends of the material to prevent fraying.
Download cutter9 and clothes peg 1 stl files and render cutter9.
slice and print
This stl produces a holder for elastic material up to 25mm width.
Developed in OPENSCAD: cutter3.scad file attached. this has instructions on how to change the length.
The author hasn't provided the model origin yet.