There are several versions of German coils made on piano wire when stringing a piano; in this demonstration and photo album we look at making the single looped coil with three turns on the tail. There are other versions; the double looped coil with three turns is a common one also; then both of these with either a left-handed or right handed tail. I have also come across German coils of types, the single loop and the double loop, with only one or two turns at the tail.
With any piano stringing, the more one develops a technique over time, the better and more consistent the coil making looks. When using a looping machine for the first few times I would encourage the attempts to be practice on spare wire, until such time as the loops and coils begin to become consistently the same size and amount of turns. This does not take long to learn consistently once familiarized with the way the looping machine works.
One must also be aware that the tied end of the wire with the tail end must come over to meet the other side of the wire, so that in the end result, the length of wire is almost a complete straight line. In other words, while this demonstration is of a left-handed coil, one must also notice in the last photo of the photo album, that the left side does indeed come over to meet the right side, leaving the length of wire beyond the loop and coil in a straight line. This is an important part of German coil making; if done so that the two sides meet in the middle of the hitch pin, this will pinch the length of wire on the back side with too much angle, causing the string to eventually break when pulled to pitch.
Here is the link to the photo album with a looping machine making the German coil.