MAGNET

551 606 28A MAGNET is typically found doing duty in a position sensor, maybe on a feed cylinder, a rotation unit, or even a rod handling system. It’s usually paired up with a Hall effect or reed switch sensor, and together they send a signal back to the rig’s control system. Basically, as the component it’s attached to moves, this MAGNET passes by the sensor, telling the machine’s brain exactly where things are at any given moment. It’s a simple setup, but it’s absolutely critical for accurate machine operation, especially for automated functions like auto-drilling or precise rod changes.

When this MAGNET starts losing its magnetic field, or if it gets knocked loose or damaged, you'll usually notice some pretty erratic behavior from the system it's monitoring. Maybe the feed won't stop where it should, or the rod changer gets confused about its position, leading to jams or even damage. Sometimes, it's just an intermittent fault code popping up, saying a sensor isn't reading right. I've seen rigs where the drifter just randomly stops impacting because the control system thinks it's at the end of its stroke, all because this little MAGNET either lost its juice or got bumped out of alignment.

Replacing one of these isn't usually a huge, complicated job, but getting the alignment right is absolutely key. Don't just slap it on; make sure it's positioned correctly relative to its sensor, usually within a few millimeters, following the service manual specs. A lot of guys forget to check for any metal swarf or crud that might have stuck to the old MAGNET, which can mess with the new one’s magnetic field or even damage the sensor itself. Always clean the mounting area thoroughly before you put the new one in place.