End Delivery ShuttlesHow the end delivery shuttle works: The end delivery shuttle uses a pirn that remains stationary, instead of a free spinning bobbin. The weft yarn unwinds off the pirns tip when the shuttle is in motion and stops unwinding when the shuttle stops. The yarn comes off the pirn and goes through a set of tension pads and comes out of the shuttle at a constant tension. This even delivery of weft causes less draw in, which in turn makes better selvedges.