3D Printed Fake Capacitor Compartment

by adriancubas

3.8K2117

Intro: 3D Printed Fake Capacitor Compartment

Electrolytic Capacitors are everywhere. If you have opened some of your Electronic Equipment you will notice that those plastic-coated metal cylinders are almost an inseparable component of these. The Electrolytic Capacitors in their internal composition have a winding of a thin aluminum layer and a spacer paper impregnated in an electrolytic. It's amazing how long this winding can go, even on small capacitors! These ideas suggested me that perhaps these Capacitors could be an excellent Secret Compartment. In this INSTRUCTABLE I detail the steps I followed to build one.

Important Note: For SAFETY reasons, the equipment you intend to use for this purpose should not be connected to the AC line again.

STEP 1: CHOOSE THE EQUIPMENT THAT WILL CONTAIN THE FAKE CAPACITOR

It all depends on what you want to hide. There is a wide variety of Electrolytic Capacitors, from very small to quite large. If you want to hide bills or some small objects, medium capacitors, approximately 50mm long and 22mm in diameter, will be adequate for this purpose. These types of capacitors are very common in Desktop Computer Power Sources(ATX). This type of Capacitor was the basis for my three-dimensional modeling.

STEP 2: REMOVE THE ORIGINAL CAPACITOR

NOTE: ELECTROLYTIC CAPACITORS MAY REMAIN CHARGED EVEN IF THEY ARE NOT CONNECTED TO THE LIVE LINE. USE SPECIAL CAUTION BEFORE TOUCHING THE TERMINALS WITH ANY PART OF YOUR BODY. BEFORE ANY OPERATION SHORTEN THEM WITH AN ELECTRICALLY INSULATED SCREWDRIVER. IF THEY ARE CHARGED THEY CAN JUMP SPARKS !!!

For this purpose, previously identify which are the terminals of the capacitor you want to remove. Heat the junction of the terminals of the Capacitor with the PRINTED CIRCUIT BOARD (PCB ) and unsolder each terminal. It is likely that some manufacturer has placed silicone glue as an extra fixation of the Capacitors, remove part of the glue in order to release the Capacitor you want to move. With a small upward force the Capacitor can be easily be removed.

STEP 3: REMOVE THE PLASTIC COVER FROM THE CAPACITOR

For a long time I thought that Electrolytic Capacitors were plastic, well no, although they have that appearance they are aluminum externally.

We need the plastic cover from the original Capacitor. With a sharp Cutter cut the plastic cover lengthwise and keep it, also the plastic circle on the opposite end of the Capacitor terminals.

STEP 4: PRINT THE 3D MODEL AND SAND DOWN POSSIBLE IMPERFECTIONS

You can print it yourself or use some online service. The TINKERCAD website easily offers this possibility. If you print it yourself be careful not to slip it while it is printing. In my case I used a small amount of acetone at the beginning and with that I achieved a good fixation.

When this part is coated with the original capacitor plastics, no imperfections should be noted underneath. That is why I suggest sanding the piece giving it a smooth finish.

STEP 5: GLUE THE PLASTIC COVER TO THE FAKE CAPACITOR

Put a small amount of glue on the faces of the Fake Capacitor and glue the plastic covers of the original Capacitor. Take care that there are no creases. Evaluate the appearance of this operation and assess if it really looks like the original Capacitor. Appearance is the key to this Project. Nobody should suspect that it is not an original Capacitor and that it may contain something inside.

STEP 6: COVER WITH SOLDER THE HOLES OF THE ORIGINAL CAPACITOR IN THE PCB

You should take care not to leave the gaps in the original Capacitor uncovered which could attract attention. Use the soldering iron and tin and apply enough solder to cover them.

Erase any trace of solder flux. With a cloth impregnated with isopropyl alcohol or a similar substance, clean the junction so that no residue remains.

STEP 7: GLUE THE FAKE CAPACITOR PLUG TO THE PCB

At the time you removed the original Capacitor you should have noticed the polarity marks that these have on the PCB. When you screw on the Fake Capacitor, the polarity bands on the plastic cover should be in the proper position. For this I suggest firstly screw the Fake Capacitor cap on its cylindrical body, place a few drops of Instant Glue in the center of the cap and then glue the assembly in the proper position. Let the glue work for at least 10min.

NOTE: ONLY USE THE NECESSARY AMOUNT OF GLUE. AN EXCESS OF GLUE CAN BLOCK THE THREAD, SO TAKE ACTION FOR THIS DOES NOT TO OCCUR.

STEP 8: PLACE YOUR VALUABLE ITEMS INSIDE THE FAKE CAPACITOR.

When the glue dried, unscrew the body of the Fake Capacitor and place your valuables inside.

I have done some experiments and they fit up to 10 bills ! or a sheet of A4 paper after many folds or some other small objects.

After this operation, screw the FAKE CAPACITOR body back into position. You should not notice differences between the original capacitor and this new Secret Compartment.

Finally, to avoid Accidental Reconnection of this equipment to the AC line, cut the Power Cables from the input connector.

When I finished this project, I went to a friend's house with this ATX Power Supply and told him that inside there was a treasure, that he was free to keep it if he found it. I didn't say anything else and I retired. Then he called me telling me..." I had opened the ATX, all those electronic components were Treasures for those who know to use them..." When I showed him the Secret Compartment, he freaked out. He had missed the chance to keep the "One Dollar and Fake Plastic Diamonds " treasure .

Good Luck !

Important Note: For SAFETY reasons, the equipment you intend to use for this purpose should not be connected to the AC line again.

15 Comments

Akiyama 3 years ago

Nice idea :)

I would also add a note, that after unplugging the psu from the grid, those capacitors can remain charged for up to few days, which may be really harmful or even deadly. (If the PSU is designed correctly, they will discharge quickly, but who knows).

adriancubas 3 years ago

Thank you luklev for your comment and subscription. This was one of my initial concerns when I did this project. As you indicated, these power supplies have discharge resistors that should quickly discharge the capacitors once disconnected from the AC line, but we don't know if they are working properly. I had already added a note on this, but maybe I should highlight it. A good idea would be to use electronic devices that have been unused for several days. Good luck.

liquidhandwash 3 years ago

Great idea, best hiding place ever! why not glue a fake to an empty part of the board, and leave the original where it is, then the power supply would also work too

adriancubas 3 years ago

That would be an excellent idea! In the case of the ATX, space is very limited and finding a place to stick the "Fake capacitor" is a challenge, however, on another device it would be very feasible. Also note that it will be an "excellent secret compartment" when the PCB tracks match all the top components. I am so glad you enjoyed it! Thanks!

tercero 3 years ago

Well. I admit I would never look there. Not much room for "valuables" though. Not a knock on the instructables btw. It's good.

rebeltaz 3 years ago

Umm... maybe I missed this, but I did not see anywhere in here where you mention that the equiptment should NOT be powered back up with the original capacitor missing. That capacitor is there for a reason.

rebeltaz 3 years ago

:) Thanks... it looks really good, though.

vishalj.svp 3 years ago

Awesome idea and implementation.

Penolopy Bulnick 3 years ago

Neat idea! Is there any danger of this being a fire hazard or melting?

adriancubas 3 years ago

I don't think there is any danger at all. This "dummy capacitor" does not connect to any electrical terminal and is completely dielectric.