The first time I tried to build these kind of tracks did not end well. The older kits had the tracks on sprues and I lost alot of track pads cutting them off. I also tried to build a jig for the tracks and it worked out ok but I felt it was lacking something. I fell upon an idea that I could use clips to help in the track build. The first picture shows two tracks, one held by a clip and the other attached through the track pins.
The main idea was to have the second track hanging down so the track pins would be out of the way. The next picture shows application of glue to the area where the track pad will be attached.
I try and apply glue with the streched sprue so none will flow into the area of the track pins.
It takes a little practice and sometimes you will need a bit more or less glue.
The third picture shows how to pick up and apply the track pad with the streched sprue.
Their is a little glue left on the sprue so it can be used to pick up a track pad and move it into it's position. After the pad is in position the sprue can be moved off the pad, leaving it in place. Another application of glue can be made at the joint of the track and track pad to help keep them in position. I do 7 clips of tracks & pads, then I join them up a few at a time until I have a run of 12 X 6. I then glue 3 runs of 12 together and add 2 more for a 38 run. I make another run of 38 for the other side. When all tracks are joined I flex them out to make sure they are flexable.