Stopping A Bench Grinder Quickly

In every workshop ever, there's a power tool that goes unnoticed. It's the bench grinder. It's useful when you need it, and completely invisible when you don't. We take the bench grinder for granted, in part because we keep it over there with that box of oily rags, and partly because it's so unassuming.

But you can really mess your hands up on a bench grinder. Words like ‘degloving’ are thrown around, and that doesn't involve actual gloves. For his Hackaday Prize entry, [Scott] is adding safety to the ubiquitous bench grinder. It's called the Grinder Minder, and it aims to make the humble bench grinder a lot safer.

There are a few goals to the Grinder Minder, most importantly is DC injection braking. This stops the grinder from spinning, and if you’ve ever turned off a bench grinder and waited for it to spin down, you know there's either a lot of energy in a grinder wheel. Grinder Minder also adds accidental restart protection and an actual ANSI-compliant emergency stop. All of this is designed so that's it's a direct drop-in electronics package for a standard off-the-shelf grinder.

The early prototypes for the Grinder Minder have the requisite MOSFETs and gigantic wire-wound resistors , but the team has recently hit an impasse. The current market research tells them the best way forward is designing a product for bigger, more powerful tools that use three-phase power. The team is currently researching what this means for their project, and we’re looking forward to seeing where that research lands them.