I have a 4"x3"x1.5" plastic box that contains my product. I need to cut a precise hole in the box to allow micro usb access. I’m currently using a Dremel, but the accuracy doesn’t look all that professional. Any suggestions? I googled for a die, but couldn’t find one
unless you are fabricating your own micro-usb plug in which case a 1/4" or 3/8" hole might work you have to deal with what the size of the plug housing [covering of plug itself] and i rarely see under 1/2" for those. but with a dremel i’d suggest using a mini diamond hole saw that has a guide bit unless you have the dremel drill stand and can lock the case to the stand base. in that case a sized drill bit will work. amazon has several dealers.
Typically you would make this kind of slot with a mill.
You might be able to make a slot template with a piece of aluminum or steel and keep the dremel speed low if you only have a few of them.
If you only have a couple of them, just use two drill hits and a set of plastic files. If you’re very careful, you can get professional-looking results.