The Final Rotary Tool – Putting Your DIY HDD Cutter to Real Work

You’ve disassembled the hard drive, extracted the motor, wired the ESC, and implemented PWM control. Now, it’s time for the final chapter: building the actual rotary tool and using it in real tasks. In this last part of the series, we’ll mount grinding discs, test cutting ability, and go over safety and upgrade tips. Your junk hard drive has now transformed into a functioning mini machine. This isn't just about spinning parts—this is about utility. Grace’s rotary tool now has the precision, speed control, and durability to handle tasks from metal polishing to circuit board trimming.     1. Attaching Grinding and Cutting Tools The original platter of the hard drive rotates perfectly flat and stable. That makes it ideal for attaching abrasive surfaces like sandpaper or lightweight discs. Option 1 – Stick sandpaper on platter: Use double-sided tape or adhesive-backed sanding sheets. Option 2 – Replace platter with cutting disc: If the spindle hole ...