eastwood, Sleepy Creek recommends using their setter to initially break-in the springs over the base, but after initial break-in you really don't need them for the 3s. I've been setting their 3s just fine by hand without the setter. Because I use their setter for 330s, it wasn't an additional expense for me.

I don't remember exactly what the issue was, but some people had problems setting them right out of the box without breaking them in first. I'm sure someone will chime in and provide the details.

Okay, so something's not right with the traps obviously. If I remember correctly, some people were having problems with the base plates deforming slightly when trying to set the 3s and 4s normally - breaking over the knee/thigh. Once the base plate had deformed, the only way to set them was with their setters.

SCM came out with a "solution" that recommended breaking them in with their setters several times before attempting to use the normal setting technique, or just use the setters all the time. I did the former and haven't had any problems setting my 3s since. There was a thread on all of this several years ago but I can't find it.

Anyway, sorry I wasn't much help.