Test Tube Bubbler




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[[Video(http://www.youtube.com/watch?v=g-QZ4Cnm-6Q, {width:500, height:400})]]

Calling Dr. Frankenstein...

Have you ever felt the urge to laugh maniacally while unknown liquids bubbled madly behind you?

Well now you can with your very own Test Tube Bubbler, and we'll show you how!

*Instructions for maniacal laughter not included

Step 1: Supplies and Tools

• Plastic test tubes
• Fish tank air pump
• Tubing for air-line
• Airline tube T’s
• Silicone caulk, Tub and Tile
• Wood – ¾” plywood
• Paint – brown or other dark color
• 4 Pumpkin lights with 3 LED’s each(available at Dollar Tree)
• Package of 1-1/4 coarse screws
• Spare assorted gauge wire
• Glue sticks
• Soldering equipment(flux and solder)
• Water
• Food coloring(optional)
• Glow Sticks(optional)
• AAA Batteries

• Drill bit same size as your test tubes diameter
• Drill bit same size as your LED diameter
• Drill bit same size as the tubing diameter
• Soldering iron
• Glue gun
• Drill
• Wire cutters
• Paintbrush
• Scissors
• Circular saw
• Tape Measure
• Pencil
• Screwdriver
• Permanent Marker

Step 2: Cutting the Wood

From a piece of ¾” plywood, cut the following dimensioned pieces:
1. 2 pieces at 6” by 13 – ¾”  Sides
2. 6” by 12 – ¼” Bottom
3. 2 pieces at 3” by 12 – ¼” Un-drilled piece is the lower front, drilled is the lighting assembly
4. 2” by 12 – ¼” Test tube rack
5. 9” by 12 – ¼” Backboard

Step 3: Drilling

In one of the 3” by 12 – ¼”, measure in ¾”strike a line from end to end along that measurement. Measure over 1 – ½” from each end. The intersection of the lines will be the centers of the first two holes to drill. Evenly space the remaining six 1” centers along the same ¾” strike line. Drill three quarters of the way thru the board, making sure to leave enough wood remaining to fit your lights and tubing (this is the divot in which the bottom of the test tube will set).

In the 2” by 12 – ¼”, repeat the above measurements, strike at ¾” from edge, in from ends 1 – ½”, space the remaining evenly. Drill this board thru completely with the 1” drill bit.

In the 3” by 12 – ¼” you just divoted, switch to tubing sized bit. Drill thru the remaining wood in the center of the divots. Next chuck out for the LED sized bit, drill three evenly spaced holes thru the remaining wood in the divot around the center hole you just drilled.

Step 4: Disassemble the Pumpkin Lights

Using a small screw driver, pull out the screws holding the cover to the base. Leaving the light circuit board exposed.

Step 5: Unsolder the LED’s

Using the solder gun, de-solder the LED’s from the board.

Step 6: Cut Wire and Mark

Cut six strands of wire approximately 8” in length. Mark three of the six strands of wire to be your + side.

Step 7: Solder(x3)

Using the circuit board as your guide, solder the wire to the positive and negative sides of the circuit board and to the positive and negative sides of the LED’s. BE CAREFUL NOT TO FLIP THE WIRES, if you do it won’t work. Repeat this for each light.

Step 8: Strengthen Power Supply Wires (optional)

We went ahead and swapped out the thin wires from the power supply to the circuit board for a little more resilient prop. Simply pick a larger gauge of wire than is on the board and repeat the above steps for attaching.

Step 9: Adding Hot Glue

Adding hot glue is a great way to keep your solder joints protected, especially in something you plan to keep for years. Add a little squirt of hot glue over each solder point to give it some protection.

Step 10: Putting the Lights In

In the three outer holes you drilled in the bottom piece insert the LED’s till flush, add a ring of hot glue on the lights underside to give stability. Pick four random holes to put the lights in for a more aesthetically pleasing look in the end.

Step 11: Assembly – Secure All With Screws

Attach the lower front piece to the top of the bottom board. Lay the lighting assembly board on top of the lower front board with the divots to the back. Match the bottom edge of the backboard with the bottom edge of the lighting assembly board. Attach the test tube rack, with the ¾” holes to the front, approximately 3 – ½ up the backboard from the lighting assembly board. Next attach the sides, matching the bottoms and fronts up.

Step 12: Painting

Take your paint color and paint it all over, being careful to keep the paint off the LED’s.

Step 13: Drilling the Test Tubes

Using the drill bit the same size as the tubing, pick the middle of the bottom of the test tube, carefully drill a hole in 4 of them.

Step 14: Measure and Cut the Tubing

Measure the distance with the tubing from the center whole in the lighting assembly bar to the top of the back board piece of wood, cut. Repeat 3 times.

Step 15: Silicone

Seat the tubing to the hole you just drilled in the test tubes, seal with a small ring of calk.

Step 16: Connecting the Pump

Re-insert the open end of the tubing thru the whole in the lighting assembly bar. Pull tubing back to the top of the back board; insert three T’s into the open ends of the tubing leaving one end of the last T open for the tubing to connect to the pump. Hold these in place with screws. The reason for running the tubing up the back gives the pump head. Fit the pump under the lighting assembly bar, measure and cut tubing to connect it to the open end of the T.

Step 17: Adding Water and Food Coloring

Fill test tubes approximately ¾ full with water. Turn on your pump to make sure all the fittings are tight and watch it start to bubble. Switch on the lights. Try adding a drop of food coloring to the bubbling water to give it that extra eerie glow so imagined of a mad scientist.

Step 18: Glow Sticks(optional)

Want to take it up one more notch? Grab some glow sticks and activate. Carefully cut an end off and pour the now glowing liquid into the bottoms of your empty test tubes.

Step 19: Laugh Maniacally

You’ve just successfully built a Test Tube Bubbler for your own Mad Scientry, dim the lights for ambiance and get to work on your maniacal laughter. Thanks for building!

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    33 Discussions

    It can if you push the corks in tightly, yes and no, it's such a small pump it would just pop the seal on a T before it would hurt the tubes. Playing around with it some I found the best was basically to just set the corks in the tubes and not push them down. Then it works perfectly, all the tubes bubbling evenly.

    Thanks. I was wondering if you drilled the corks... Very nice project. I may try to do a portable version for Halloween. Thank you!

    You actually don't wanna drill the corks, you need some resistance to direct the air flow. Since the bubbles will go only to the tube with the lowest resistance. So we used the corks to help balance the resistance in each tube.
    This version would actually be really portable. The only issue is the pump we used is a wall plug version. I have seen battery operated ones. The pump we bought is meant for a 5-15 gallon fish tank and is running 1200 CC. Hope that gives you some parameters to buy yours.

    Harbor Freight has portable bubblers that run on C batteries, and they are markedly cheaper than the ones sold at aquarium stores or sporting goods stores.
    And drilling the corks will still work, just make sure that the total area of the drilled holes is less than the area of the tubing in cross section. You can also buy little needle valves at the aquarium store to control each tube's bubble rate if you want to over engineer this thing

    Haha, yeah my roommate had to reign me in from over engineering it. I'm an industrial engineering student with a passion for fluid mechanics, I could have built this thing to bubble in the exact sequence I wanted. However, thanks to his wisdom, we went simple. We decided to build this so people with little to no experience could copy it. When you start drilling the corks the fluid flow mathematics can get complex really quickly, especially if people use different liquids than just the water. If you drill your stuck with just liquid you drilled for. I found by playing with the corks I could run different densities of liquids at the same time. By forcing more resistance on the water corks I could get it to bubble thru oil and glow stick innards at the same rate.
    Ease and variability was the name of this game. Thanks for the suggestion of where to find the portable pumps, I had absolutely no idea where to find those.


    5 years ago on Introduction

    You could combine the several big plastic pumpkin lights to just the main PCB, and use a single set of AA batteries to run them. They last for hundreds of hours, so you might only be able to get 50 hours or so out of them... Oh nooo...

    4 replies

    I built this so people that have little to know experience with electrical could make it. When you start seriesing power supplies and linking LED's you can get into some math that can be over a lot of people's heads. It's a great suggestion, but it would require explaining how to calculate resistances of things to keep from blowing your LED's.
    The second reason I went this route is to keep the flickering of the lights completely random as each of the pumpkin lights has a flicker. If you series them all, the lights would all flicker on and off at the same time. Would this be a big deal to most, probably not, but for my aesthetic, I liked the random.

    that would have been a big deal to me, the perfect symetry of something that's supposed to be random, in this case chaotically malfunctioning, would constantly annoy me, if you can build aboard that will still have the random look i'd be interested.

    If you are using the soldering iron, then you are already out of the range of most people without electrical experince.

    And no maths are involved. Just take one pumpkin base with the battery holder, and hook the three units to one power supply.

    All in all, good job though. I forgot to mention this in my last post. Sorry about that!

    Haha, depends... I have a friend that makes stained glass for a living, he can wield a soldering gun like no other, but he has no idea when it comes to wiring boards, but I totally get your point ;)

    Ok, I can see that working, but wouldn't the LED's be dimmer, since the higher power drain?

    No trouble drilling the plastic ones with a hand drill. The glass ones are trickier. I would recommend trying a drill press with the tubes in a block vise. Oh and make sure you have glass rated bits. They're usually sharper and sometimes have a bit different spiral. Please let me know how it goes, it would be useful to share with others.

    They are a Martha Stewart Halloween item, usually your local craft stores like Joanns(where we got ours), Michael's, Craft 2000, or Hobby Lobby will carry them. I'm not sure if Martha Stewart has her own website, but I would suggest buying in store, cause coupons are AWESOME!