Introduction: Toolbox Power Supply

About: I am an architecture major at the University of Florida living in Italy. I have a passion for making and previously participated in FTC, Mate Underwater Robotics, and TSA.

First off, I am a sophomore high school student who actively participates in FTC Robotics representing Shark Beta Team #10088 and FatherBoards Team #10087. The goal of our robotics team is to learn as much as possible before graduating and going off to college. Recently I purchased my first toolbox! Naturally while looking through Home Depot I saw the ridiculously expensive box with the outlets, lights, speakers, and even a MINI FRIDGE! After seeing this and checking out the price tag :) I decided I needed to buy the smaller box and make it awesome myself. This is going to be a multi-part instructable starting with the basic power supply that will power everything else in the toolbox and function as a bench top power supply. This project is going to be made using an old computer power supply that was donated a while ago. I decided to use the larger computer power supply versus making my own smaller one because I wanted it to be reliable, I had it on hand, didn't have another use for it, and it will be as sturdy as the toolbox itself because of its metal body.

I hope you enjoy my instructable and please give it a vote because winning this competition would greatly help our robotics program and further our knowledge in making and engineering. Thank You!


Please be careful when working with the computer power supply because it has high voltages and current that could KILL YOU! So please be careful.

Step 1: Parts

These are just the parts that I decided to use and what I already had but you can substitute many of these parts for others.

Step 2: Tools

These are some basic tools that you will need, all of the tools I used are listed but you do NOT need all of them.

  • Soldering iron
  • Drill
  • Several Drill Bits
  • Hot Glue Gun
  • Flush Cutters
  • Wire Stripper
  • Scissors (You can rip the paper too but scissors are nice)
  • Marker
  • Riveter (Make sure it fits the rivets)
  • Pliers (Preferably needle nose)
  • Super Glue (De-bonder is nice also)

Step 3: Voltage Wires

In this step you are going to be identifying the wires on the connectors and then soldering extension cables to the output wires.

I have done the pre-work for you but the first thing I had to do was refrence the pinout of all of the connectors to find out which cable outputs what voltage. I choose to start from the lowest voltage and work higher and higher. I have attached the reference picture i used above and if you are unsure (or colorblind like me) please reference this picture.

  1. Cut all of the 3.3v orange wires away from the connectors
  2. Cut them to the same length
  3. strip about .5 inch from each wire
  4. twist all of the wires together
  5. cut a long segment of speaker wire and split about 4 inches down
  6. strip about .5 inch off the wire with the white strip
  8. Solder the two wires togther and heat shrink
  9. Next repeat steps 2-8 with half of the red wires
  10. Finally repeat steps 2-8 with all of the yellow wires

At this point you should have all of the black ground wires, green power wire, purple, blue, and gray wire unused and still attached to the connector. The rest of the cables should be cut and soldered with one side of the speaker wire unused (other then half of the red wires).

Step 4: On-Off Wires

This is just like the previous step except with only two specific wires. This step will also allow you to be able to turn on and off your power supply when you want as to not just waste power.

  1. Cut the singular green wire and any black wire
  2. Strip about .5 in from each wire
  3. Cut a long segment of speaker wire and split about 4 inches
  4. Strip .5 inches off both sides of the wire
  5. Place heat shrink on both speaker wires
  6. Solder the green wire to one wire
  7. Repeat this with the black wire on the other wire
  8. heat shrink the wires to prevent shorting

You have finished the power wire that will have the switch attached to it to turn the power supply on later.

Step 5: Ground

This is where you are going to take all of the black wires and cut them from the connectors. Then divide the wires evenly among the three voltage out lines. this will allow each power wire to have its own designated ground (even though they are all connected together).

  1. Cut all of the black wires
  2. Strip 4 of the black wires
  3. take the second speaker wire soldered to the yellow wires and strip .5 in off
  5. solder the 4 black wires to the second speaker wire
  6. Heat shrink it
  7. Repeat this with 4 more ground wires on the red 5v wires and 3 wires on the orange 3.3v wires

Now you should have 4 speaker wires fully active and ready to solder the banana plugs to the other end.

Step 6: Cut Unused Wires

In this step, you are going to be tracing the wires into the power supply and cut them from the board. This can be very dangerous so do not cut wires you are unsure of and try to avoid unnecessary touching.

  1. First, unscrew the screws on top of the power supply and remove the cover
  2. trace the gray wire to the board and cut it as close as you can to the board
  3. repeat this with the purple, blue, and excess red wires
  4. hot glue over the unused wires to prevent shorting
  5. Label all of your wires as to which wire is which voltage and the on-off
  6. now take a large diameter heat shrink and slide it down all of the wires
  7. heat it to shrink all of the cables together
  9. reattach the cover of the power supply

Congrats you are done with the dangerous portion of the instructable from now on out it should be easy sailing.

Step 7: Measure, Measure, and Measure Again

In this step, I am going to decide where to place the power supply itself, where to drill out the banana plugs, and where to route the wires. It is going to be broken down into sections for each set of holes

Power Supply

  1. Take off the cover of the power supply and look for where rivets can go
  2. mark holes on the lid of the supply to where you can rivet
  3. now make a paper template of the holes so it can be transferred
  4. mark a line to the middle of the ENTIRE supply and then transfer that line to the template
  5. This line will allows you to center the supply on the rear of the box


  1. Find the middle of the box with a ruler
  2. mark the middle and align the paper template (make sure it is in the correct orientation to line up the holes)
  3. do this by aligning the center mark on the template and line n the box
  4. tape the paper template in place

Wiring Bottom

  1. with the power supply aligned mark where the wires will enter the box
  2. check the clearance behind the hole to ensure there is room
  3. Make the wire hole a rectangle so it will be large enough to fit the wires cleanly

Wiring Top

  1. Now open the top of the tool box and look for where you want your outputs
  2. I chose to laser cut a box on top so I can tap into the rails later
  3. mark 4 holes about 1 cm apart so the wires can fit trough
  4. make a paper drilling template

Now that you have finished all the hole marking please check the clearances of EVERYTHING at least 3 times because you don't want to have random holes in your box and then run out of room.

Step 8: Drill Holes Carefully

In this step we are going to drill through the box with the least amount of damage, cut out a rectangle for the wires, and soften the holes so they don't fray the wires.

Power Supply Mounting Holes

  1. Because I am riveting my supply into place the drill bit I used is 1/8"
  2. please drill the holes with the lid of the power supply off
  3. place masking tape on top of the holes you will drill and mark again
  4. now carefully drill through the top of the supply trying to keep your alignment straight
  5. Next onto the box side
  6. remove all of the drawers so you do not drill into them
  7. Then place masking tape underneath your paper template and take the same size drill bit and carefully drill your marks out
  8. I chose to place the power supply top onto the back and redrill the holes so they are perfectly aligned
  9. Reattach the lid of the Supply

Wire Hole

  1. First take the outlined hole you want for your wires and drill 4 holes in the corner
  2. Then take a metal cutting Dremel and connect the holes
  3. File the cuts so they are not jagged and look perfect

Banana Plug Holes

  1. Open the top of the box and masking tape over your marks
  2. Then drill through your marked holes on top of the tape
  3. try to do this as straight as possible to avoid excess damage

Clean up Holes

  1. You are going to use a small file and remove the metal burs from your holes
  2. this will prevent fraying of the wires

Step 9: Mount Power Supply

In this step, I am going to show you the proper order to mount the power supply onto the rear of the box.

  1. feed all of the wires through the rectangle hole
  2. pull the wires so the power supply is touching the rear of the box
  3. turn the tool box right side up
  4. take 4 1/8 in by 1/8 in rivets and place them through the tool box and then into the power supply
  5. carefully hold the power supply tight against the back and rivet it into place
  6. Repeat this for all 4 rivets
  7. (If you miss one of the rivets you need to take your 1/8 in drill bit and drill into the rivet. This will break the rivet and allow you to take it out)

Step 10: Wire Manage

In this step, we are going to manage the wires in the back of the box so they do not get caught in the drawers or locking mechanism

  1. Take a zip tie harness and place it directly above the cut-out rectangle
  2. Zip tie the wires tight against it so they are as flush as possible
  3. Repeat this step all the way to the top of the box and where you drilled your banana plug holes
  4. Try to keep your wires as flush against the back as possible
  5. For people that love wire management try to use straight lines

Step 11: Banana Plug Box

in this step, I am going to show you how to assemble the box with the banana plugs in them and how to wire them together. (You will need to laser cut the box with the provided ai file, there are alternatives if you don't have a laser cutter)

Banana Plug Screw Down

  1. Take the laser cut top and 3 red and black female connectors
  2. Unscrew the connectors completely
  3. Remove all the parts besides the very top one
  4. Feed that through the hole
  5. Reattach everything in the same alignment it came in
  6. tighten with pliers so they do not come loose


  1. Feed each of your 4 wires through the four drilled holes
  2. With the hole, all the way to the left make that the switch wire then in descending voltages to the right
  3. now cut the wires about 7-8 inches from the hole
  4. (This will allow you to add things to each of the rails later like lights or speakers)
  5. Split the wires about 3 inches then strip about .5 in

Crimping and Soldering

  1. start with the negative wires and crimp the tabs onto them (This should be done to all of them except the switch)
  2. Next connect all of the negative crimps to the correct voltage on the banana plugs
  3. With the negatives connected check you have your voltages correct
  4. Solder all of the positive wires to the red
  5. Before glueing the walls check the voltages because it can still easily be changed now
  6. (If you do have the voltages wrong unscrew the top nut and switch them arround)
  7. New feed the on-off wires through the switch hole then solder the wires to the switch (the orientation does not matter)
  8. Now press fit the switch into place

Box Assembly

  1. Now you need to assemble the surrounding box
  2. the orientation of the sides does not matter because it only fits on one side
  3. after you glue it together attach 4 magntes to the cornters so it can be removed later
  4. Now go under the top and pull the excess wires through
  5. this will allow power output to click into place via the magnets

Step 12: Congrats

Congratulations you are on your way to having the coolest toolbox ever! please check my upcoming Instructables to upgrade your tool box even further. Hint hint just like all computers today this is going to be an RGB led box or even a speaker system!

If you enjoyed my instructable and would like me to continue this series please leave a like and vote for me in the Power Supply Contest! It would greatly help our robotics program, Thank You!

P.S. If you notice any issues with the instructable please comment so I may fix them ASAP as I will be reading every comment.

Power Supply Contest

Third Prize in the
Power Supply Contest