Spider Spitter 1

Our giant spider spits shaving cream at unwary visitors!

Give your spider the gift of spit!

Mechanism
What to spit?
Control
Related Pages

Mechanism

Did we forget to mention that our little pet spits shaving cream at unwary visitors? We actually had two of these. The one on the small tripod attacked from the side. The other one was on the roof, near the front of the spider.

[spider spits] Here, Gadgeteer David holds the Spider Spitter 1.
The squirting mechanism starts with a rectangular frame made from extruded aluminum stock. You can see one side of the frame, as the vertical bar in the picture. The spray can is strapped to the frame with small bungies.
Another rectangle of aluminum is attached to the top of the first one, at a right angle. This second piece extends over the top of the can. From the side, the complete frame looks like the inverted letter L.
The upper frame has a slot in the center. In the slot is an aluminum lever, hinged to the end of the upper frame. In this picture, it goes from right to left, giving a T-shape.

Parts are not critical, except that you get them to fit together. The solenoid is a 110 VAC pull model from the electronics junkbox. Leverage is used to give it strength, so it need not be particularly strong. Try the usual surplus stores: Jameco, Hosfelt, MPJ, All, Goldmine, Herbach.

[photo] This setup is actuated by a solenoid that is mounted on the main frame. When actuated, it pulls the lever down, and bingo!

[photo] Attached to the lever is a bolt, sticking down, toward the can. The idea is that, if you were to pull the lever down towards the can, the bolt would press down on the nozzle, dispensing the cream, as if you had pressed the nozzle with your finger.

If you are spitting shaving cream, you have to replace the stock nozzle with one from a can of spray paint to make the cream shoot out in a stream.

What to spit?

The squirting mechanism is general, and can accommodate almost anything in a can. Our first thought was Silly String, but decided against it because of the debris. We used an ordinary can of shaving cream, with the nozzle replaced with one from a can of spray paint. You might need to hunt around to find a paint can nozzle that fits the can of shaving cream.

A very frequently asked question is "How can I get my giant spider to squirt Silly String?" Let me list the reasons why this is a bad idea:

Once shot, Silly String debris will hang around, making a mess that you have to clean up, and tipping off the kids about what is to happen.
Silly String tends to come in bright fluorescent colors that glow under black light. It might be great while it is being shot, but the debris is even more obvious. In 2000, I saw it in black for the first time, but still don't like it for spiders.
Silly String is flammable, presenting an actual hazard. There have been stories on the e-mail lists about people who have used this stuff at birthday parties, only to have it ignited by the candles.

Shaving cream, on the other hand:

Cleans up with water - a spray with the hose makes it vanish.
Left to itself will dry into a powdery residue that can be swept up.
Is inexpensive, being produced by many companies for many consumers.

Control

The squirting mechanism is quite dumb. You give power to the solenoid; it presses down on the button; the spray can shoots stuff until it is empty.

The spitter is best used in short bursts.

In 1999, we simply plugged the spitter into an X-10 module modified for momentary activation. It worked fine most of the time, but occasionally got stuck "on". I believe this to be the fault of the momentary X-10 hack.

In 2000, be used an X-10 module to trigger a darkroom timer, which fired the spitter for a precisely timed burst.

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Thank you for visiting. Your comments are welcome.
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Spider Spitter 1

Mechanism

What to spit?

Control

Related Pages