I did scan and print a local statue that does "spit" for like 2-3

I did scan and print a local statue that does “spit” for like 2-3 seconds every minute or so. Does anyone have an idea how to recreate this in an easy way? Would a solenoid and a small aquariumpump do the job?


A small aquarium pump without the solenoid would work fine. Just turn it on and off.

I would be looking for a cam driven pump that sucks fluid on the down stroke and expels it on the up stroke using a slow cycle motor. This way there is no timing circuit to fault an could be very quiet due to its 2-3 second cycle.
Like the old farm kitchen water pump or a boat bailer.

@Richard_Orth nice idea!

One would use a solenoid to turn on such a pump in order to allow something such as an Arduino to operate it. If an aquarium pump is not sufficient, a windshield washer pump from an automotive source would certainly work. Still need a relay, solenoid or solid state switch of some sort to permit Arduino triggering. I’m not sure about the easy way, if an Arduino is involved, but it’s not like those are difficult to configure.

A combination of a planetary gear reduction https://www.thingiverse.com/thing:2122538
and a peristaltic pump
might also work. You could remove two of the bearings pressing the tubing, creating a single chamber out of four but the work cycle would be also one out of four, not so much a few seconds out of two minutes.

Some careful selection of motors and gearing would make the concept more complex than an Arduino running a windscreen washer pump!

@Rene_Jurack was trying to think of the name of the pump type. Its a piston pump https://en.wikipedia.org/wiki/Piston_pump. Could probably make the parts or even incorporate it into the statue.

just trying to think outside the box, what if you found a kid’s toy with moving parts and tore it apart…

even something like that singing fish would have a motion sensor

or a toy with remote controls if you want to be able to control it

garage sale would be cheap :slight_smile:

budget, skill, and time always produce different results. Off the top of my head. two reed valves (intake, outflow), a syringe, and a gear motor hooked up to a wheel with a diameter equal to the length of the syringe plunger connect with a push rod (like a locomotive wheel).

@james_scott1 I like the way you think. I’ve recently become aware of the SeaGlider project by roboboat. It uses a syringe and a 360° stepper motor to pull water in from outside the sealed chamber, changing the center of gravity of a neutrally buoyant winged vessel. Slow CoG change is preferred in this case, but an eccentric design of the manner you describe should work nicely. The “nozzle” end of the system could have the outflow valve as a simple flap, preventing air intake on the syringe downstroke, while the inflow valve could be a thin plastic or thin rubber washer inside the syringe covering a hole or holes in the base of the syringe, which would be immersed in water.

Easiest way is to buy a battery powered water gun and rip out the pump.

Fred, they also sell fountain pumps for about $20 that you could hook up a “flasher delay” from the olden days (remember those signs that would blink on and off at a slow rate). Far less to fabricate. Just set the delay to the time interval you want.

Super please follow me


Sorry, wrong one.

I have these, they are loud af… :thinking:



Where are you going to get the water from? If you have water pressure a solenoid valve and cheap timer module would be a durable solution. If you need a pump you can try to use a diagram pump with a pressure shutoff valve and a pwm controller if its too loud.


Very nice