This Instructables shows how to reuse old USB battery pack power some tiny tools.
Step 1: Why?
I found many old USB battery pack when I tidy up my room. It mostly come from gift and souvenir. Their capacity often very low, and mostly only can output 500 mA, It is hard to treat it as a backup battery for the current mobile. But I think the old USB battery still can power a bunch of tools.
The first tool I would like to make is a tiny screw driver. When I repairing my gadgets, I need to screw in and out tens of screws, but I don't want the high torque of a normal electric screwdrivers hurt the tiny screws. So I want to make a tiny screwdriver to help me the screwing work.
Step 2: Prepration
USB Battery Pack
Don't buy a new one, just find some in your drawers.
Interchangeable screwdriver set
something like this: https://detail.tmall.com/item.htm?id=520149044454
USB Type A male break out board
For getting USB power.
N20 Micro Metal Geared motor
1:298 gear, 3mm or 4mm D shape Axle.
Axle Shaft Coupler
The size depends on your screwdriver set adapter and motor Axle.
6 feet 3 files ship switch
For switching motor rotation direction.
2 M3 x 6 mm screw for fixing USB breakout board; 6 M3 x 8 mm screw for assembling the case.
Step 3: 3D Print the Case
Just print both side, a and b, with your 3D printer default normal or low quality setting is good enough.
Step 4: Patch Screwdriver Adapter
Cut the screwdriver adapter and connect it to the axle shaft coupler.
Step 5: Connect Motor
Connect the other side of axle shaft coupler to the Motor.
Step 6: Soldering Work
- Connect USB power to the ship switch middle feet
- Cross connect left and right side feet of ship switch to make a motor direction control circuit
- connect motor to the ship switch right side feet
Step 7: Assembly Component
- Put the motor and ship switch into the case side a.
- Screw in the USB break out board with 2 M3 x 6 mm screws.
Step 8: Assembly Case
- Put case side b on the side a.
- Screw in 4 M3 x 8 mm screws.
Step 9: Plug USB Power
- Direct connect the tiny screwdriver to the USB battery pack.
- If the battery too big, you may connect with a USB extension.
- If you do not have a battery pack, you may connect it to a USB power adapter
Step 10: Happy Fixing!
Now you have a tool help you screw in and out tens of screws!