Tinkering with building a weasel box out of a newspaper tube. Got plenty of tubes, thought why not convert some to weasel boxes. Got a removable recessed "door" figured out with Wisconsin legal 4-day check opening, but thinking about a tip up on top to indicate fired rat trap.

How to mount a compression spring on top of plastic tube? Thoughts?

Need to be able to "screw" the compression spring in on site so I can stack a dozen tubes into a pack basket and hike into the marsh.

Can you opt for a surveyors flag and eliminate the compression spring altogether? You could remove the flag for ease of transporting and insert it once on location.

If I eliminate the spring, how do I "set" the flag so it goes up when trap is fired? I'm thinking along the lines of a surveyor's flag but stuck into the end of a compression spring so it can lay down flat on top the tube. When the trap is fired, the flag is released via monofilament through small holes in the top of the tube to the holding bar of the rat trap,

When finished please send pics.

Check out Seldom Fales on YouTube. He's always got some great ideas. Here's what he uses for his "weasel tip-ups".

https://youtu.be/2JYoI2h2WvU?si=m76TEDa1RkL6-FCA

When I flagged my 160s all I did was stick the flag under the trap dog. When the trap fired up went the flag. I rolled up the flagging material when I set It but It came undone when it went off.

Get some of those flags they use to mark utilities when bent down they have enough spring left In them to stand up. Cut a slot In the tube and place the end of flag under the kill bar. You should cut down on the amount of flagging and cut it back from the end of the wire so you don't have any flagging under the kill bar.

Good stuff there, thanks