Introduction: Explore Underground With the M.O.L.E.

Ever wanted to know what was going on beneath your house? What about that hole in your back yard that keeps appearing over night? Ever wonder what the inside of your sewer line looked like? Me neither, but yes to everything else!

What started as a project just to sink a camera into a lake, slowly evolved into a simple inexpensive multi-environment probe. I have always wanted to learn about everything I could and I felt that it would be more rewarding learn this knowledge through discovery, not a textbook. However the goal is to observe with minimal impact to the creature I was observing. The inspiration for this project actually came from two things:

  1. The Open ROV
  2. This phrase from the guidelines of a contest, "tools and gadgets that make exploration a lot more accessible and exciting!"

So when building this probe I wanted it to be something that anyone could make with a very basic skill set and a very friendly budget. What I came up with was the M.O.L.E.





Pretty much a fancy name for a camera that could be shoved into anything that is just a little bit bigger that itself. I felt for something like this it needed a anagram.

The list of necessary materials include:

  1. A USB or Ethernet camera (I used the last one on this list)
  2. One foot PVC that fits your camera (Mine used 1 1/2 inch)
  3. (2)PVC caps that fit your pipe
  4. Plexiglas
  5. Three Red LEDs
  6. Electric paint
  7. Electrical Tape
  8. One cone spring
  9. Heat shrink tubing
  10. Three 2032 batteries
  11. Small key chain flashlight
  12. 50-100ft of CAT5 Cable
  13. 22 gauge wire
  14. 1/4(Tall) x 3/4(Wide) Weather Stripping
  15. Silicone
  16. USB Extender

List of necessary tools include:

  1. Jeweler's screwdriver kit
  2. Hot glue gun
  3. Dremal and various attachments
  4. Hobby knife Or something sharp in general)
  5. Soldering [Gun, torch, iron, etc]
  6. Lighter
  7. Hacksaw
  8. Portable computer (aka laptop)
  9. The longing to explore

Oh and yes I know the video was overdone.

Step 1: Gotta Start Somewhere

So naturally when making a portable camera that first thing we start with is a camera. Everything from here on out will be based around the camera you choose. Smaller cameras will allow more freedom in the exploration department.

For the camera I used, taking it apart consisted of removing the framing ring (Fig. 2) around the lens to expose two screws and the shell easily became two separate parts however there was some glue holding the USB cable in place. After removing the glue t the USB cable and remove from the shell. I do not recommend using a Dremal to cut away the shell my first cut actually cut into the circuit board but missed the important parts, I was lucky. Important! Cut the USB cable as short as you can but remember, while a shorter cable means a smaller probe it also leaves little room for error. Now that you cut the cable close to the camera do the same thing near the USB plug. From here you just need to reconnect the wires and you should be left with a camera and a cable only four inches or less. Another thing to note is that there is a microphone cable provided but it would be useless in a closed capsule like what our camera will be in, go ahead and cut it way.

Step 2: Finding Your Capsule

This is a simple step. Take the expose camera to a hardware store and find a PVC pipe that it fits inside. If you are using the same camera as myself then the pipe will be 1 1/2. The reason for choosing PVC pipes goes as follows:

  1. Easy to aquire
  2. Water-proof
  3. Pre-made fittings that fit in a very snug manner
  4. Can withstand larger amounts of PSI
  5. Easy to work with

Many hardware store will sell the PVC by the foot and that will be more that enough for this project (size it very important). After getting the pipe you need also get to slip on caps for it as well. One of which will be used for making the lens you see the picture above.

Step 3: Create the Viewing Port

The viewing port to put simply is a slip cap with the top cut off and Plexiglas put in its place. Now those who are familiar with the PVC fitting aisle in stores might be wondering, "Why not a coupling?" Size. Coupling are longer than a cap because it has to accept pipe from both sides, while a cap it only meant to plug off one end to keep water from coming out.

So to kick it off choose your least favorite (or your favorite depending on your views) PVC cap and cut the top off it. Make the cut just below the curve. Doing so will allow you to slide the cap all the way on while having plenty of room for the lights and lens.

Next place the cap onto a sheet of Plexiglas, trace it and cut out a square with the circle you traced in the center. When cutting on the Plexiglas be sure to score the glass deep enough before you try to snap it off, m firs tattempt left me with two triangles instead of a nice little square. WARNING! Be careful not to remove the plastic film the protects the Plexiglas, we don't want to scratch it before we get the chance to abuse it.

After cutting out the square warm up your glue gun and put three or four dots of glue around the edge of the cap and place the square onto the cap. Be sure to line up the edges. Do not glue the Plexiglas down all the way yet because in the next Step we need to remove it to install the lights. I had the misfortune of performing this mistake and ended up sending about 30 minutes with a hobby knife trying to cut it free. This went on until I slipped and shove the knife into my middle finger.

Now that we have the square of Plexiglas attached to the cap, grab you favorite tool and work the Plexiglas flush to the edge of the cap.Personally I use a Dremal with a sanding drum to work the shape in. Once this has been accomplished remove the Plexiglas from the top of the cap and move to the next step.

Step 4: Give the Gift of Light

Now the the Camera has something to see through we need to provide it with something to see with. If you haven't done so already remove the Plexiglas from the cap and decide where to put the three red LEDs. The placement of the LEDs should make a triangle around the inside edge. Make a rough guess on how wide and long you need to make the notches. The goal is to have the LEDs sit just below the lip of the cap's edge so that they are not in the way of the Plexiglas when you put it on. This is truly a trial and error thing, the main thing is to avoid punching a hole all the through because that is just another thing we would have to seal and another point of possible failure. It is possible to not cut the notches and to just glue the LEDs to the inside edge, but you would have to be extra careful positioning the camera so you don't get them into the shot.

Once all of that has been achieved hot glue the LEDs in place. but take care in the direction they are facing. WARNING LED are sensitive to positive and negative power flow. This can be determined by looking at the two legs coming off the LED. One of them will be longer than the other one, the long one is positive. When gluing them down make sure a long leg will be paired with a short one to begin the circuit. If you look at the Second Picture you will see black dots where the legs over lap. These black dots are globs Electric Paint by Bare Conductive. I got a tube from RadioShack but they are closing shop across the board from my understanding. Anyways when the paint dries it conducts power pretty well from my experience and helps to hold the legs in place.

As for the remaining two legs solder long pieces of wire to each one, about 14 or so inches will be more than enough. You want them so long for when you take the caps off you will have the slack needed to pull away the caps. As for the other ends leave them hanging we will get to them soon enough. After making that quick solder take a strip or two of electrical tape and line the inside of the lens. This will keep the light moving froward and not blinding the Camera.

Once all THAT has been done you are now ready to add the Plexiglas lens to the cap. sing your hot glue gun put beads between the LEDs do not put glue over the top of the LEDs this will make the scatter and become less effective. Once the glue is down push the Plexiglas lens on and hold it there til it hardens you can speed it up by blowing on it. Once the glue is harden there should be gaps between the Plexiglas and the edge of the cap. Now is the time to show off your mad Silicone skills and fill in the gaps. Once again only put the between the LED not over them. For the gaps by the LEDs just make a Silicone barriar on the outside edge all the way around the seam of the Plexiglas and cap. This will close the gaps by the LEDs and any other you may have missed.

------------------------------------------------------------------------------------------------------Now I want to take a second here and explain my choice of lighting. If you don't want to see the reasoning please move to the next step now.

Red LEDs, of all the colors why red? Those who are familiar with animals and the outdoors know that red doesn't harm your night vision for the most part and as a result will not scare animals as quickly as a white light. This is due to it's low energy level compared to say a blue light.

Ever notice your vision gets a little fuzzy or your eyes start to hurt when starting at a screen for long periods of time, especially in the dark. This is because many monitors emit lots of blue lighting straining our eyes. For comparison think of a drop of water constantly falling and hitting your head. Does it hurt? No, but it is annoying. Now think of a rejected Bond villain who strapped you to a chair and aimed a tennis ball launcher to your head on low power and 10 second delay. Did that hurt? No, what about the next? No again? How about the 20th? 50th? 100th? Eventually the spot it is hitting becomes sore and tired making it hurt. Same thing with your eyes.

Cameras "feel" the same effect so to say. Lets say I stuck just a normal white LED onto my camera. Out in the open no problem but as soon as I put it down a hole the light is funneled in two directions: further down and right back to the camera. White light has plenty of energy so is gets reflected with vengeance. Red light does not contain as much energy allowing much more manageable lighting levels. A secondary reason is that when you drop this into water Red is the first color you will lose due to absorption in the water, that's why divers carry lights in the day to provide the missing colors in the deep.

Step 5: Little Bit of Power

Whats an LED without power? A lump of plastic with legs and we need to change that. Before I go in depth on the creation of a battery pack decide: Do I want a neat little battery pack or am I impatient?" If the latter then skip this step and just tape the batteries together with electrical tape and have the wire ends taped to the appropriate ends. Your lost.

For those who wish to go the extra mile lets begin. I found this at a local hardware store and all it is, is a small LED key-chain flashlight. Start by removing the batteries from the back, this should provide you with two of the three 2032 batteries you will need. Looking into the body of the light you should see a small circuit board, use your thumb that hasn't been removed by a band saw and push it against the plastic lens. With little effort it should just pop out leaving behind it's empty carcass.

Now take the plastic lens and your cone spring. Using a pair of small pairs bend a "L" into the end of the spring and then drill a hole just big enough for the "L" to go through. Hot glue the spring into place and place the lens back into its spot on the old flashlight. Ad a little more hot glue to the lens just to make sure it doesn't pop out by accident.

Next drill a small hole in the body of the flashlight for you other wire to be place into. Most of these small flashlights save space by using the body of the light to conduct a charge and power the lights. We are going to take advantage of this fact.

DO NOT CONNECT THE WIRES YET! At least not in a permanent fashion, you can twist them together to test the connection but nothing more. Later we are going to thread them through the same hole as the CAT5 cable shown above.

Step 6: Expand the USB

OK, I will admit this Step will be the least exciting because there is not DIY here, you have to by a part for this step. Unless you bought a CAT5 camera, if you did skip this part and move to the next step.

So this first part is more of a justification, you are going to have to buy a USB Extender. Now its not really just a longer cable, but instead a adapter from USB to CAT5 back to USB. Before you think about it, there is not reliable work around so don't just Solder a CAT5 cable to the end of a USB it won't work I tried it. In fact I spent more money that I wish to admit trying to prove the internet wrong, but when the people of the internet are from this site they are generally right. So just save yourself time and money and just take that link above to the least expensive one I could find (If you know of a cheaper one can you leave a link in the comments). I wasted about two days researching and another two or three days experimenting, nothing worked I could find. Good new though is that to now allows the USB to run up to 150 ft and better models allow even farther.

Step 7: Make the CAT Door

Your going to need a 15/64 drill bit for this step. that is the size that is just big enough for a CAT5 cable to squeeze through WITHOUT a jack on the end. What you will need to do is cut off the jack you still have it on. Remember to leave yourself enough wire to solder it back on.

If your one of those fancy aristocrats just push the cable on and use your crimp tool to just put a new jack on in like half a second.

Now we are done with this step be prepare to bring everything together.

Step 8: It All Comes Down to This

It is time. Grab your foot long piece of PVC and measure is out to about 6 inches. Cut it. Done? Whew, hard step.

But hey since we're here lets assemble everything.

Start by feeding those two long wires through your 6in piece of PVC, then feed your short USB cable from your camera through as well. From here position your camera to one side of the PVC pipe. this will create a small gap for the LED wires to run through freely as you pull the cap off and put it back on. This can be seen in the second picture. Hot glue the camera in place, and I recommend having it hooked up to a computer so you can see where it is pointing before committing and having it accidentally pointing to the wall of our new capsule.

Now that the camera and lens are in place go back to the other end and gather up the wire connected to the LEDs. Take those two wire and thread them through the same hole as the CAT5 cable. Once they are threaded through grab the battery pack we made earlier and double check which is positive and which is positive and which is negative. When that is determined solder the wires to their correct location. One thing to note is that a lot of those mini flashlights are made from aluminum and can be hard to solder to, I ended up soldering, hot gluing, and taping one of the wires down because it kept trying to sneak off. When all the wire are connected to their battery terminal slowly pull the wire through the hole so that the battery pack is now snug up against the cap and glue it in place (Fig 5).

Alternate Method: If you are the lazy kind and just taped the batteries together ignore everything you read and just tape the wires to the batteries and stick them inside the capsule itself, there should be enough room.

Next use your Silicone to generously seal around the hole on the outside and the inside. Do not use Hot glue, I tried because I wanted to dried faster. It resulted in my capsule being half filled with water on the first test. Something interesting though was the fact that is didn't harm the camera and it kept recording the whole 5 mins it was underwater, don't chance it though.

Leave your Silicone exposed to air for at least 8 hours to dry and don't place it onto the body of the capsule, this just make water vapor inside of the housing and it take forever to remove it. Once the Silicone it dried take the USB extender and hook it up inside of the housing and close it up. Do the same on the other end and plug it into your computer, checking that everything worked.

If so Congratulations! You now have a camera ready to start spying on the underground world. So go out and bring the glory of the M.O.L.E. people to the boring overworlders.

Don't make the same mistake Tips:

  • Put a sheet of the screen protectors you use on phones to the Plexiglas to save it from scratching. This idea didn't occur to me until I found a inch long scratch across my lens.
  • Focus the camera to about 2 inches in-front of the lens when going underground because everything will be close and personal to the camera.
  • If you see any bubbles about the size of a dime or more pull it out of the water, it leaked.
  • Place a small cloth bag with a drying agent inside of the capsule, it will help keep the lens from fogging.
  • Everywhere you splice a wire insulate it with heat shrink tubing or electrical tape.

The next step is just how to add some water-proofing if you are so incline to dropping it into water. because Yes Moles can swim. Note this isn't me I just found this video.

Step 9: 1200 Inches Beneath the Sea

So you want to be a Submarine Captain huh? Well before you sink beneath the waves we need to keep the water out. To do this we are going to need electrical tape and Closed cell rubber foam.

The foam is easily found in Hardware store under the name of Weather Stripping. The dimensions you want are 1/4 inch (Tall) and 3/4 inch (Wide). Put the caps on all the way on both side and unroll a length of the Weather stripping. Wrap the Weather Stripping around the body of the capsule where the cap meets the body. That way it always closes to the same spot and minimizes the gap. Do this to both ends. Make sure the weather stripping is nice and tight and not hanging lose or has any wrinkles. Once this has been done wrap the seam with electrical tape starting above the seam on the cap and over lapping the previous wrap by about half. Pull the Electrical Tape really tight to make sure no water gets in. Visually inspect the wrap if you see any wrinkles or bubbles pull it off and try again, those will create leaks. Due this on both side and then wrap the CAT5 cable to the center and use a hose clamp to hold it in place. This will make the level with the ground so your looking forward and not straight down. When adding weight you will need to adjust the balance again unless you are really good.

Doing all that was described above will keep water out and air in, meaning it will float. To combat this I zip tied (or cable tied for those back east) a weight to the bottom of the Capsule. To be more specific I tied a 5 lbs bar of Soldering lead to the camera. It worked so well that when it reached the bottom of the lake it kept sinking through the mud on the bottom. For me that was the most exciting part because the visibility of the water around where I live is less than 2 feet on a really nice day.

Bonus Configuration: We have 100 ft of cable why be limited to the land and sea? Lets take to the air!

With a little bit of tape you can attach the camera to the end of a really long pole and look into local bird nest to see what is going on in there.

Use your imagination this camera has a long range of vision and it pretty hardy. I would love to see what you guys find, Have Fun!

Explore Science Contest

Third Prize in the
Explore Science Contest

Animals Contest

Participated in the
Animals Contest