Step 1: Gather Materials
Aquarium pump (EHEIM 200 was used for this project)
Flexible aquarium tube, inner diameter 5 millimeters (this should fit on your pump)
Dlexible small tube, inner diameter 3 millimeters
Normally-closed switch. After pushing the switch needs to return to his rest position by itself.
Regular on/off push button
Electric wire, no ground (minimum 2 Meters)
Small heat shrink > depends on amount and type
Akimichi vacuum pen
M3 bolt, M3 nut and roundel (couple of cents per piece)
3D-printed tool (straw + ring)
Step 2: Reverse aquarium pump
First, reverse the aquarium pump. Normally the pump blows air, but you have to open it up and reverse the valves to make it suck.
Step 3: Cut one of the two electric wires
After reversing the pump, dismantle approximately 7 centimeters of the cable of the pump. Next cut one of the two wires and dismantle both sides.
Step 4: Attach the push button
Open up the push button and attach both parts of the cut wire to the connection part of the button.
Pushing the button will create a connection between the two cut wires (ON: the pump starts). Pushing again will interrupt the connection (OFF: the pump stops).
Put the button back together and test of it works.
Step 5: Step 5: Cut the plug off and dismantle
Cut the plug off from the cable and dismantle the end (4 centimeters). Dismantle also the wires inside the cable. (0.7 centimeters)
Take the end of the electric cable and do exactly the same here.
Step 6: Open up switch and poke holes
Open up the switch. Poke holes in the two opposite sides. There are two soft circle spots on the switch, which were created to make these holes into.
Step 7: Insert the two cables through the holes
On one side you insert the dismantled cable of the pump through the hole.
On the other side you insert the dismantled electric cable through the hole.
Pull them both far enough through the holes. This will make the next step easier.
Step 8: Connect a wire
Connect one of the wires of each cable to each other.
This can be done by soldering them together and attach a heat shrink. Here a special heat shrink with glue was used. Each wire needs to inserted on one side of the heat shrink. Squint the sides together with a pair of pliers and heat it up until you see glue coming out on each side. Let it cool down for a couple of minutes. Test if the connection is strong enough by gently pulling it.
Step 9: Connect other wire with switch
Take the connection part of the switch and put the other two wires in it. Take a good look at the electrical scheme and make sure you put the wires at the right place according to this scheme. If you push the switch the current will be interrupted temporarily. When releasing the switch it will return to its original position, letting the current flow again. So the pump will be constantly sucking. If you push the switch, it'll turn off and stop sucking so the picked up piece will be released then. The pump will start sucking again from the moment you release the switch. If you want the pump to only suck when the switch is pushed you need to remove the black wire from 1 to 1.
Step 10: Add a elastic band to the switch (optional)
Add an elastic band to the switch so it can be attached onto something. There are two holes on the bottom of the switch. Put the band through the holes and simply make a knot on both sides. If the knot is big enough, the band is attached to the switch.
Step 11: Put the switch back together
Put the switch back together and make sure that no dismantled parts of cable can be seen.
Step 12: Add a plug
Dismantle the other end of the electric cable and put a new plug on it. Attach the two wires to each of two pins of the plug. If you have a plug with a ground, you just don't connect anything to it and ignore it.
Test if every switch and button works properly before moving on.
Step 14: Attach piece of aquarium tube to the pump
Attach the aquarium tube to the pump on one side. Make sure you turn the power of this side at its highest and the other one at its lowest. You can do this also by adding a T-junction and turn both sides to their highest. However, there is no difference between the two options, so putting it only on one side while the other is turned off leaves you with less work.
Step 15: Attach flexible tube to aquarium tube
The flexible tube was found as a part of baxter that you are used in hospitals. A second tube was used because the aquarium tube was just too little flexible and little bit too heavy to handle. This is personal so if the aquarium is flexible and light enough for you, you don't need to put an extra smaller tube.
Step 16: 3D-print the custom pieces
These are the files that need to be printed (STRAW + RING). Choose one of the formats (.igs, .stl, .prt).
It's a custom ring and some kind of straw. The size of the ring and the length of the straw should be adapted to your specific wishes. After printing, remove the print supports and scour the impurities.
Step 17: Assemble 3D-print pieces
Connect the straw to the ring with a M3 bolt and nut. (Look at the pictures) Place a roundel between the parts so it still can rotates afterwards. Cut the bolt to the right length, if it's necessary.
Step 18: Connect the tube to the straw
Slide the tube over the right end of the straw.
If you only used the aquarium tube, this should also work.
Step 19: Connect vacuum pen head
Take on of the twisted heads of the vacuum pen and slide it over the other side of the straw. It should fix itself.
Pick one of the two largest suction cups and place it on top of the head.
Step 20: Ready
The product is finished and ready for use.
Switch on the pump by pushing the push button. Pick a puzzle piece with the suction cup and release it by pushing on the switch.