Introduction: Hydroponic Pump From Recycled Battery Operated Weed Killer Sprayer

About: The best things in life are dangerous.

This Instructables will show how I recycled an old battery operated weed killer sprayer in to an automatic hydroponic pump, or to pump any light fluid for any purpose.
You will need one used battery operated weed killer sprayer, wash it out with liquid dish soap a couple times, don't want to leave any chemicals in in.
An x-10 universal module.
Some wire for remote switch.
1/8" I.D. length of clear tubing.
A rechargeable 7.2 V battery.
The sprayer is battery operated, it holds 4 AA (6 volts) batteries but never seemed to work great, in this instructable I upgrade the power source to 7.2 volt rechargeable battery, which could be charged with a small solar panel.
I used an x-10 universal module to control the pump. X-10 automation software to run pump 4 times a day at regular intervals.

Step 1: Disasemble the Sprayer Gun

Locate the screws holding it together, remove them. Pry the bottom open and work towards the top, the top has snap fit bosses on the inside. It will pop open when persuaded enough. Inside we find a small dc motor driven pump, a trigger switch, battery compartment and the spray nozzle. To remove the pump, I cut the wires.

Step 2: Pump Nozzle Modification

We now can remove the spray nozzle,use a screw driver and pry between the pump housing and the clear plastic nozzle tube and collar. Use care it's all plastic. After you get that off attach a long piece of 1/8"clear tubing.

Step 3: Swich and Power Modification

These steps will show how to bypass the existing trigger switch and adding a remote switch. Also wiring in an extension from the battery compartment to a higher voltage rechargeable battery. These steps could be skipped if you use the existing battery compartment and the trigger switch as is. But I wanted to control the pump remotely, and using a external power source I can give the motor more voltage. I tested this pump and it will turn on 6 volts minimum, but it was able to take up to 12 volts. 12 volts seems a little much as it spun insanely fast. With the right nozzle and 12 volts this would make a hell of a super soaker. But that would be another instructable.
First identify the positive tab on the battery spring, that is where you need to solder or connect one lead from remote switch and positive lead of a power source 6-12 volts DC. The negative lead from power will connect to the black wire,and the negative side of the motor. The other lead from remote switch will connect to positive side of motor ( shown in the next step.)

Step 4: Switch and Power Modification 2

Here we see the positive side of the motor connects to one lead from the remote x-10 switch, the other lead from switch connects to positive wire from the power source. The negative wire from power connects to - side of motor. Test it before you position the wires for reassembly.

Step 5: Reassembly

You will need to make the notches bigger that the wires and supply hose to pump will fit through. Make sure the hose is not pinched off when you reassemble the two halves. That's it, your done! Now you can remotely water your hydroponic garden with it, like me, or you can use it to pump whatever remotely.
Remember if you use this for garden or fun be sure you wash the container well before use.

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