unless you own an industral punch press or unlicensed liner accelerator there is a booby trap just waiting to "spring" in your house.
go out in your garage and look above your garage door... there are two coiled springs that act as counterweights for your garage door... quiet, silent but loaded with 200 to 400 pounds of wup azz.
came home to a garage door that wouldn't open, mind you I use my garage door to get in the house, don't even have a key to the front door on my ring. Found that one of the recoil springs had snapped (glad I wasn't around for that). Ok, fine, zip out to "home cheapo"... what, no garage springs? Least the guy at Manards was 1. informative enough to tell me they don't carry them because of the liability, and 2. nice enough to tell me that Farm and Fleet does carry them...
first step is to take the tension off the remaining spring
I've jumped into a turn with the back wheel dancing and the front squealing... and I've never been more afraid then twisting on that last set screw.
pulled it apart, old and busted off, new hotness on. Kept ... most of my skin on my fingers and blood in my body... and tensioned the springs until the door weighed only 10 pound or so... The garage door opener lifts it just fine now...
Mine has a "danger orange" tag on it telling you that death will occure if you look at it cross ways... but those wern't required until 2000, so if your house is older... It looks quite and harmless... but it's not