I got rid of my windless tip ups a couple of times in the past, but I always manage to get a few more.
They are a pain to set up, but can be like magic on the right day.
The setting of the flag is critical, otherwise it won't 'trip".
Bend the flag arm so the tip of the flag is set behind the spool.
You want it to trip if any line is pulled out.
Here's a website that I found that can explain it much better. There is a section on "windless" tip ups.
http://icefish.com/online_media2.htmlHope this helps,
Wiener