Easy print. Works great. Got 2 mice the first week after I got the platform balance right.
I used one quarter and glued a large washer to the platform for the counterweight. The magnet I used must be extremely strong. I had a surveillance camera on it, and saw that it wouldn't trip with a screw opposite the magnet. The mice would just sit on the platform, eat the peanut butter and go home when it was all gone. I had to remove the screw, and put a set screw in its place. I screwed it down and recessed it about 3/16 ". Then it would trip when the mice got to the end of the platform.
I made a wooden ramp about 2 feet long, with two ears that hooked into the orange back of the trap. I put a couple of dabs of peanut butter on the ramp to entice them up it.