Is it allowed for men to shave with a haircut machine?
Shaving is allowed by a 2 bladed (or blade against the shield) scissors-action, but not with a 1 sharp blade. The way to test each shaver is by taking off the shield/head, and try it on the hair of your arm. If it still cuts, it's forbidden, but if not, then it's considered a scissors-action and is allowed. Specifically regarding hair-cut machines, at least mine is clearly a scissors-action, where you see the blades moving against each other in order to cut. BTW, all this is good regarding one's face, but regarding the side-burns (until the top of the cheekbone, which comes out around the middle of one's ear), even with that scissor-action, it's still prohibited to shave all the way until the skin, and the hair must be left long enough that one is able to grab it between his thumb and pinkie.