About MeNo personal information shared.
- Peter, sorry about taking so long. Once log in got fixed all I got was a scrambled site.
Spring back is the softness of the wire. You say several times that you have hard wire and your customers confirm this so let's look at a couple of things.
1- What is the purity and quality of your copper rod? Quality starts here! If you rod is all recycled material it is entirely possible that your problem starts there.
2- Here wire producers make rod and copper wire to ASTM specs and magnetwire producers make wire to NEMA specs. I had privilege of working at the same company as Marshall Yokelson and he showed us that there are area around 1mm when the specs don't agree.
3- You are doing inline drawing. This machine is not designed to be a typical wire breakdown machine! The inline drawing machine should be supplied with soft wire and then reduced 30-80%. The inline drawing machine is designed to allow you stock fewer sizes of wire for enameling. Typically 3-4 supply sizes can be stocked and will allow you to enamel 8-12 sizes ( I am talking AWG sizes - obviously any number of specialty sizes can be made within the range of the machine).
4- in the late 60's or early 70's at GCC Buena Vista we tried a BICC inline drawing machine and years later I bought several package SICME systems for the company I worked for and later even built a couple for SICME in the USA.
5- One of the unique things about inline drawing is that when you supply it with good annealed wire, reduce it at least 30% and no more than 80%, the pre annealer essentially becomes a wire cleaning device depending upon the number of passes you make through the enameling oven and the enameled wire will have good elongating, a higher tensile strength, and good spring back ( meaning softer)! This is because metallurgical the grain structure is near perfect. I can dig out my books for the particulars.
6- Any imperfection or reduction I rod quality will affect this as will over drawing or under drawing during the inline process.
Summary: first thought is your problem is starting with the wire you are inputting.