Guys those who interested to make a simple grinder for small scale use can try this....
All you need is an old HDD, can be easily get from a computer shop.
Step 1: Parts required
1. Old HDD
2. 230Ac - 12v, 2A circuit board (you can also use 12v,2A step down transformer or SMPS)
3. Emery Sheet
4. Push button type micro switch
5. SPST switch
Open the HDD & remove front cover,actuator & magnetic disc.
Now take the magnetic disc, cut same size of emery sheet & stick it on the disc.
Place the hdd & circuit board on a plastic box.
attach the push button switch & spst swich on the side of box.
HDD has a tendency that when there is no usage the spindle will automatically turn off. So to get a continues spindle rotation just short "reset & ground" pins on the ide port. To identify the pins look at the picture.
Connections from these pins are given to push button & SPST switch
Mount all parts on a plastic box & give connections.