The high stresses placed upon the winder means that what might otherwise be a simple construction job requires considerable care in design and execution. Not much work is needed to do the job, but I am proceeding slowly, thinking through each step instead of doing a rush job.
For the core of a ten inch (26 cm) spool, I am using a nine inch standard plastic reel with sides cut from resin chopping boards. The size I chose just happens to be the maximum size of chopping board that I could find, but I expect it will be enough to increase the capacity of the 9 inch reel from 700 feet to 1000 feet (300 meters). The photo shows a trial assembly. I plan to use 24 bolts on each side of the finished spool to spread the stresses over several bolts.
