How to make a Tension Spring with Loops. 

One can only wonder if Neil had any concept of the fate to which he sentenced dozens of Purdue engineering students when they left this comment 2 years ago, for now judgement day is upon us and we are all to be martyred for his insidious curiosity.

@@lessercrow If only someone had answered the question before it got turned into a quiz :(

​@@lessercrow Hi Paul

If the entire spring body on the part shown is coiled to full length, then the lower coil splitter support tool will need to be offset MUCH farther tot he right!! this may actually cause a tool collision interference with the cutter holder. It only takes an extra millimeter here or there to become a deal breaker on a setup plan. The tool workspace clearances are usually very rigid and fixed on multi slide CNC wire forming machines and the setup guy who designs must be mindful of those limitations. In the spring example shown, the setup guy overcame the long spring body by only coiling part of it, so he could split the loop from underneath and use the top slide for the split punch. the consequence is it has to be drawn back to the coiling arbor and the finished coiling, and that takes a little more time, but it completes the part without secondary. He could have coiled the entire body with NO front side loop split, done the last one, and cut off the part. then a secondary department would be given the springs and they would have to split the coil loops manually in kick presses. This is how it was done decades ago if you only had a standard cheap simple compression spring machine.