Murphy knew that decades ago. You can work around that by putting fake markings on the panel, like a hole for a fan that won't really be there. That way the panel doesn't know when it is time to crack. Leave the markings on until everything is done and all tools are locked away. Otherwise, when the panel realizes that it has been tricked it could gang up with the tools. I have seen Dremels that wait until power is shut off, then jump out of your hand and scratch your workpiece with the still spinning tool bit.
Rofl at nick. Anywho I have used jigsaws to cut plexi and have never had one crack/shatter...now when I used glass . But one disadvantage to using a jigsaw is if you dont have cloth/paper covering the plexi than the metal on the jigsaw base will scratch the hell out of your plexi.
If you rush the job it can turn nasty fast. The plexi I have has given some pretty horrible explosions from rushing. Wicked, wicked stuff if the job is rushed.
I once cut the side of my thumb off while working with some plexi. I was cutting it with a jigsaw, and getting impatient with how long it was taking. I started to cut faster, and the whole thing broke in two, leaving a really sharp edge on the broken plexi. My hand proceded to fall off the jigsaw and land on the sharp edge of the plexi... yeah... Some nasty stuff there.
I have a hand saw made for PVC pipes.. and when im doing short cut.. i stick it on the vise.. with the line im cutting level and visible right above the vise's grip. and then i can cut the stuff clean and fast.. no cracks.. and not loud... Otherwise when im using bigger cuts.. i have my tabletop craftsman scroll saw @ 750RPM which is the lowest possible.. and then slow and surely.. dont cut on the line, i then take the dremel sanding bit and sand it down to the line... works perfect.. what are you doing to make it crack?? like tools you are using..
