There never seems to be enough light in the shop, and when working with a band saw or drill it can be very important to clearly see what you are doing. I had an old broken lamp hanging around thought it would be good to adapt it to a magnetic base, that would let me stick the light on my tools and shine the light just where I need it. Here is how:
Step 1: Step 1 - Tools and Materials
Sheet metal ( ferrous, you want it to be magnetic ) – mine came from the case of a microwave magnet. Microwaves are often a source of parts, search the web, instructables, or as a sample see this: Taking Apart A Microwave by dog digger https://www.instructables.com/id/Taking-Apart-A-Microwave/
Donuts magnets from a microwave oven
¼ inch hardboard or plywood ( mine was salvaged from old flooring )
Remains of a lamp or other tool to mount
Saw to cut the sheet metal and hardboard
Step 2: Step 2 - Prepare the Base
Cut the hardboard so the two magnets can sit next to each other with room for a mounting hole between them.
Then cut one or more pieces of sheet metal to pretty much cover the surface of the hardboard. I used 2 layers. This material is to let the magnetic flux “flow easily” from one magnet to the next, this will increase the strength that the base holds on. Glue up ( with the epoxy) so the metal is on one side the hardboard. Use clamps and let it harden well. When the glue has set drill a mounting hole for the lamp between the space for the magnets.
Step 3: Step 3 - Add the Magnets
One face of the magnet is south the other north, glue the magnets on the sheet metal so one has its north face on the sheet and the other its south face. ( you can check this easily because 2 north faces or south faces repell each other ) Again clamps are a good idea so the magnets stay were you put them until the epoxy is hard.
Step 4: Step 4 - Mount the Lamp
The lamp ( which used to have a broken clamp base -- got it in the dump ) is mounted with a single bolt. To get the wire through it I had to cut the plug off, this is replaced after assembly. See the pictures. Of course you need not mount a lamp, a "third hand" or other tool may be useful.
Step 5: Step 5 - Use It
The base will adhere with a good amount of force to any ferromagnetic material, This includes steel cases ( except some stainless one ) and tools with cast iron parts. These are common around the shop where I plan to use this light. When you put in place try not to let it snap in place too hard as this can break the magnets which are brittle Sometimes it is easier to slide the base off rather than a straight pull. I would not mount the lamp on a hard drive unless you have already bricked it.
Step 6: Step 6 - Do It Again in Minature
The magnets from some hard drives are pretty much set up just like this base, you just need to find a way to connect to you lamp, tool or whatever I plan to use heavy gauge wire as part of my lamp so I added two bolts with washers and nuts as show in the photo. Construction time about 5 minutes. I will be using this base in an upcoming instructable. An instructable that may help in getting the magnets is: Reusing Old Hard Drive Magnets by ProfMuggs https://www.instructables.com/id/Reusing-Old-Hard-Drive-Magnets/
and there are others as well.