I used an ancient saw design to reuse broken bandsaws. The blade is tensioned by twisting a rope.
Step 1: Saw Attachment
The blade is kept in place by 2 screw terminals from an electricity meter, but you may be able to find a suitable alternative.
A slit to accommodate the blade is sawn in the legs of the frame (from a solid type of wood such as oak)
Cut out a quarter of the end to accommodate the blade holder.
Glue back a piece of the cut out to keep the blade in place.