I just came across this video today that I find extremely helpful to those that have treadles, and converting a Singer 319 to treadle. What I found wonderful about this video is that she demonstrates how a coil spring can be used as a treadle belt and the pluses to having a coil spring.
At 4:24 posting, showing how you can lift the machine up to get to the underside of machine, like for feet dog screw.
At 7:22 posting, showing the benefit of the coil spring when switching out machine heads.
http://www.youtube.com/watch?v=q83SouHBOzk
Does anyone know where I can purchase a coil spring belt?
Help! I want one! I think this is so cool.