In this instructable we are going to built a cordless min drill machine or a dremel tool. This drill is aimed to built under 5 USD so this project is going to be dirt cheap.
Have a look at the built video of this project on youtube and dont forget to suscribe to my youtube channel for more upcoming videos.
Lets get building......
Step 1: Motor and Coupling
To start with we have a speed 400 brushed DC motor. First we have fitted the coupling on the motor shaft by hammering it on the motor. Then we checked the alignment of the coupling on the shaft by a dry run.
Step 2: Base
We have used a 1/2 inch pipe to serve as a base for the battery pack as well as the switch and the charging jack. The pipe is cut down to the required length which is 4 inches.
Step 3: Battery Pack
This drill is powered by lithium polymer cells that I have extracted from an old laptop battery. While I was extracting these cells i have damaged their insulation so first I have applied some insulation tape on each of these cells to protect them from any short circuit while putting them together as a battery pack.
Later I have sticked all three cells on the plastic pipe thatI have cut earlier using a hot glue gun.
Step 4: Soldering the Battery Pack
The battery pack is made out of three lithium polymer cells each having a voltage of 3.7v at a capacity of 2200 mAh. All these lithium cells are then soldered in series to provide an output of approx 12v. This battery pack have a sufficient capacity to power this mini drill for good duration of time.
Step 5: Charging Jack
To charge the battery pack we have used a simple female socket that is compatible with most of the 12v adapter available in the market. First two wires are soldered to the respective pins of the charging jack. Usually the centre pin is positive while the side pin is negative.
A hole is then drilled in the base pipe to pass the wires through it while the charging jack is glued to one end of the pipe using hot glue.
Step 6: Motor Mounting
First we have decided to mount the base pipe to the rear side of the battery pack using CA glue.
Step 7: Wiring Everything Together
Wiring everything is very simple. both the battery terminals are soldered to the respective leads on the charging jack. While the negative terminal of the battery is directly soldered to the motor terminal and the positive terminal first passes through a switch then soldered to the other motor terminal.
Make sure to wire the motor in such a way that it spins in counter clock wise direction as seen from the front of the motor.
Step 8: Failure.....
Now we have tried to run the motor with a drilling bit. As I switched on the motor the motor starts to run at a very high speed causing enough viberation to detach it from the base pipe.
Now we need to look up for another configuration to run it successfully...
Step 9: Remounting the Motor
The motor is remounted on the cells using hot glued to provide a frim grip while the motor is running.
Step 10: End Results
The final results are good. This seems to be a useful tool for drilling small holes as well as cutting through plastic sheet. This can be handy tool to use where you cant get your cordless to perform the task.
For more information and built video please visit my youtube channel and subscribe for more fun projects.