Pond-jumper

[Jim Warfield]

Water cooled gears.
ceramic coated= no rust.
Or solid nylon?

[Greg Chrise]

Okay, who put that solid nylon gear in here? I've slipped a whole cog now.

[wipp]

was just a sugestion but good luck using your real air ram under water lol

[kpolley]

The water pump is a good idea, but there are still pressure concerns. The "lift" that you need is simply a function of the pressure in the cylinder and the surface area of the cylinder's plunger. You could get away with low pressure, but the bore of the cylinder would have to be quite large. For instance, 20 psi with a 2 inch bore will only be able to lift about 62 pounds. If you make the cylinder with a 6 inch bore (and you can easily find PVC that big) at 20 psi you could lift 565 pounds. If you are really thinking about doing this, when you size a water pump they will be rated in gallons per minute at a certain head. 7.5 gallons per minute, if you are using a 6 inch bore cylinder, will give you about 1 inch per second rise for the prop. 1 foot of head is approximately 0.434 psi so you can determine pressure rating that way. If you need to lift about 550 pounds and want a rise of, say, 6 inches a second you need a pump capable of about 45 gallons per minute at 50 feet of head. If you really decide to do this and would like a little help just let me know. Either way, I hope this helps some.

[Jim Warfield]

But has anyone ever had that much head all at once and survived?
Gregg?......

[Greg Chrise]

The prop should be made to weigh very little like 20 pounds, the 2 or 2.5 inch cylinder becomes just and extention of a submersible that does only about 3.5 gallons per minute and the true pressure is probably less than 4 psi. It isn't a hydralic seal so much as displacement of water. If you put a gallon of water in part of a volume that weighs 8 pounds pergallon and at low presures is not compressed it is no different than putting your hand in the tub and pushing it like a puppet.

The 3.5 gallon submersible pumps usually have a 1.5 inch hose and even if it was slow it would be believable rather than being a pop up creature.

If you wanted to pop up the cylinder should be pnuematic and perhaps be in a basin not really submerged in water. Sort of like a trash can terror only stuck in the water.

A still quick but lumbering raising of a creature that does not have a human shape would be more discomforting as it is not easily recongnized for anything other than what it is, an unidentifiable monster moving on its own with no air noise.

[kpolley]

Sure, if the prop only weighs twenty pounds you could do almost anything. You could just about blow into a straw attached to the cylinder to lift it. How, though, are you going to make something that large only weigh twenty pounds and, if you suceed, how are you going to make it more dense than water so it won't float? I'm afraid that by trying to make the problem easier you will make it much harder.

You can very easily make a heavy prop out of some kind of resin maybe with an aluminum or stainless steel skeleton. Build a really big cylinder and get a nice pump like the one I had mentioned and you're good to go. Off the top of my head, I'm thinking the whole project costs you less than $1000 when it's all said and done and you would have a totally unique prop that will definitely get your patron's attention.

[Jim Warfield]

I have scared alot of people moving myself or something "slower" rather than "faster'.
Pnuematics are often too fast in my opinion and people miss the scare.
Also if they are too quick the mind doesn't have any real time to get scared, it's all over with too quickly.
Dr. Frankenfurter sang about what I mean:"An-tic-i-pa-tion".
More mental involvement rather than less, then the customer feels like they experienced something, thereby adding more perceived value to the tour, maybe making them more happy to have paid for a ticket and taken the time to do the haunt.

[SSP]

Also need to take into consideration the drag of the water itself. If the object is completely submerged before hand, pushing it through the surface will be quite the task, adding more weight than in plain air. And if it only weighed twenty pounds and was quite large, would it have enough support to be forced through the water time and time again?

I've never been, and have no idea what it looks like or how it works, but what about the Jaws ride at orlando? I think it's at orlando, at least.

Also, what if you had a prop that was more of a springloaded type object and simply was reset with a crank or something like that? Maybe simple is the way to go. Looks like it's either something really simple or really expensive.

Depending upon the depth, you may need a very tall figure to lay flat to stay hidden, so maybe having some sort of a spring which stands the figure upright from underwater, a giant bungee, that sort of thing.

[Greg Chrise]

Another way to approach it is that the actual mechanisms are behind the scenery. A big under water teeter toter pushes the creature up or it is a cable operated contraption.

If floating is a problem perhaps the creature thrusts out from under a mossy spot out along the water toward the patron.

Rather than make the mechanisms high dollar and for a specific purpose, make several styles of actuator mechanisms and see what they are capable off.

For smaller low pressure pnuematics and even water pressure there are even bicycle pumps made entirely from plastic that can be converted to move things. Short strokes as well weok wonders, it need not be a telescoping actuator from a dump truck to get a thrill.

There are also counterweights. Even though the creature weighs 60 pounds and the actualtor is a submersible pump a cable and pulley with weight can be rigged to make it weigh nothing.

Then there are other physical things like if the creature is hollow and somewhat air tight and submerged, simply filling it with a big volume of air would make it float way above the water, coming up only restrained by nylon tie ropes and weights on the bottom of the pond. For quick action think a big bellows or a 6 inch tube of PVC 4 foot long with a piston or a precharge of air and a valve to blow the thing up out of the water.

My gears hurt.