Battery operated 3D printed Drill Press Laser Guide for accurately locating the spot to drill.
Step 1: Parts
This project requires the following parts:
- 2 ea Laser Line Modules 5 mw and 12mm Diameter
- 1 ea Rocker Switch
- 1 ea 18650 Li-Ion Battery
- 1 ea 18650 Battery Holder
- 1 ea A1015 PNP Transistor
- 2 ea 47 K Resistors
- 1 ea 1 K Resistor
- 1 ea Red LED 3mm diameter
- 1 ea Adafruit PowerBoost 500 Power Supply
- 1 ea Small Proto Board
- 1 ea Screw Metal Hose Clamp - Adjustable 3-4 1/2” Diameter
- 2 ea 3mm screws to secure Lasers in holder
Step 2: 3D Printed Parts
I used Black PLA to print the parts. The total estimated print time on my Prusa Mk3 is 6 1/2 hours at 25% infill, and consumes about 34.5 meters of filament. The files for this project can be found at Drill Press Laser Guide at Thingiverse. I've included a Main Body model without holes on the front panel which will allow for more customization.
Step 3: Circuitry
The circuit, as seen above, centers around the Adafruit PowerBoost 500 Power Supply which boost the voltage of the Li-Ion battery from 3.7VDC to the desired 5VDC level for the Lasers.
This project would work fine with just the PowerBoost, Lasers, Switch and Battery, but I added circuitry to indicate a Low Battery via a Red LED. This circuit consist of the LED, A1015 Transistor and three resistors. Should the battery voltage drop below 3.2V the LB pin will drop to 0V and trigger the A1015 Transistor and light the LED. I built this circuit on a 25mm x 25mm proto circuit board, and used the circuit board to wire a common battery ground and positive voltage.
The PowerBoost board also has a pin labeled EN which provides an easy means of turning the Lasers ON and OFF. However, the Rocker Switch works the opposite of what would be expected. The Lasers are ON when the switch indicates OFF and vice versa.
An easier solution, as suggested by dumb_and_dumber, would be to use a 5 VDC cell phone charger and switch to power the lasers. Excellent suggestion!
Step 4: Assembly
Run the Laser wires through the Laser Holder lower front opening up through the center axial hole and out of the top of the threaded end of the Laser Holder as shown above. Use a 3mm screw to screw into hole located on the bottom of the Laser Holder to LIGHTLY secure the Laser. The red arrow points to the head of the screw LIGHTLY securing the Laser. Place the Laser Holder with Laser into the wide end of the tapered opening, and thread the wires through the Knurled Nut. Tighten the Nut to hold the Laser Holder. Run the wires in hole on top of the Main Body and into the Control Box area.
Connect the Laser wires to circuitry mentioned previously. The Lasers are wired in Parallel. Therefore, the two Red wires are connected together and to 5VDC of the PowerBoost, and the two Black wires are connected together and connected to ground.
Step 5: Calibration
Using a hose clamp, mount the Laser Guide to the column of the Drill Press. Be careful not to over tighten the Hose Clamp...it might crush the mounting supports. Visually center the guide with relation to the Quill of the Drill.
Turn the Laser Guide ON and adjust each Laser Holder toward the center work area of the Drill Press.
Take a piece of scrap wood with a straight square edge and draw a perpendicular line to the square edge with the aid of square. Stand the wood on the Drill Press table with the line facing the Lasers. Focus each Laser, and then rotate the body of each Laser until the line is parallel to the line drawn on the scrap wood. This may require you to loosen the screw on the bottom of each Laser Holder. Once the Laser lines align with the pencil line LIGHTLY tighten the screw.
Place a small drill into the chuck of the Drill Press. Secure a piece of wood to the table and mark the location of where the drill would penetrate the wood. Adjust each Laser Holder until the line intersects the mark you made. Now, tighten the Knurled Nuts on top of the Laser Holder and double check the alignment. You're finished.
Note:The cross-hairs will indicate where the drill bit will contact the work piece regardless of the table height. As seen in the illustration above, the laser lines form two vertically aligned intersecting planes where the intersection corresponds to the center line of the drill chuck.