I’m going to differ from the pack here, and admit up front that I actually found that video of the machine chewing up big metal objects to be oddly satisfying.
In the reddit thread linked above, someone posted the video in reverse. Also oddly satisfying.
I recall reading of a wood chipper story where a landscape crew was out one day doing their usual thing: pruning or cutting trees & feeding chunks into the chipper. It was a small company and the owner was a hands-on guy who worked in the field, not in the office most days. That day the owner was the crew chief. So he was the one feeding the chipper.
Until partway through the day he quite literally fed the chipper. Somehow he got snagged on a branch and was drawn in and through. The article said his men said he was a conscientious guy who respected the danger, used all the precautions, and was not a foolish risk taker.
Bottom line:
Those things are damned dangerous even if you’re a skilled experienced user. Letting a kid anywhere near such a thing is unthinkable. To me.
I could watch those metal scrap shredders for a long time. I find them mesmerizing, and awesome; a device for which one must have a healthy respect.
And that wood chipper tragedy is just awful.
At a local farm fair they had one of those combine harvesters (like this) for kids to play on. Perfectly safe as it was shut down, but what struck me was the warning stickers above the “corn heads” basically warning operators not to try and manually clear the spinny crushy things as they will grab and pull you in faster than you can pull your arm or foot away from it.