We (Instructable member seanmichaelhunt ) and I were contracted by a Chicago event promoter to create a tank/DJ booth for their "Paint Wars" event in Milwaukee, WI. Originally it was designed to shoot fluorescent tempera paint 30-50' from the end, along with confetti and CO2 blasts. It was no small feat designing a system to effectively do all of that via one tank gun, and It came with a very large price tag. Budget constraints resulted in a tank with a UV laser effect. Entirely in fluorescent colors, it is especially super-vivid in person when hit with UV light. The front treads have a chasing effect to create the illusion of motion. We think it looks like a big children's toy, perfect since the people attending an event where you're hit with paint the whole night are still children.

Another challenge to this project was that it had to contain a functioning DJ booth, which was a greater obstacle when more significant effects were involved and had to be isolated from the DJ. Also, that it had to be assembled in a manner which could collapse into a cargo van, which was a minor miracle. Here's how we went about creating this fun prop:

Step 1: Design and Begin the Framework Structure

There are many ways we could have gone about this, but guiding our process were the facts that this had to be a nearly full scale prop, solid enough to function as a DJ booth, and disassemble easily enough to transport in a cargo van.

The framework is largely composed of 3 sections, the wheels/treads (2), and the center "cabin" section. These sections then further disassemble to some degree.

The tread sections appear wider than they are because the visible end of the treads are wider, along with upper panels which extend further out. This creates visual depth for the wheels and also makes it more compact for transporting. The front sections of the wheel treads are also separate components.

The center section is composed of three flats which bolt together, with the DJ equipment table screwing into place to further stabilize everything. The lower front section of the tank has almost no physical structure as it is a few yards of fluorescent raincoat material connected with velcro to two horizontal 2 x 4's in the center structure and wrapped around a PVC pipe to create a solid shape.

Step 2: Facing the Tank Framework

Aside from the fabric component, the rest of the tank is faced with thin, though heavy 1/8" hardboard, and primed white and painted with high quality UV paints from Wildfire. Drywall screws hold it all in place, and fluorescent gaffers tape is used to cover the screw heads where desired.

The wheels are all cut from two different thicknesses of extruded foam insulation sheet. Layered and glued together, then coated with Sculpt and Coat, a plastic like coating that hardens and protects the foam. With enough coats, the foam can be super durable.

The gun was a large diameter PVC pipe, wrapped with fluorescent blue vinyl graphic film.

The laser housing is rectangular and not able to fit inside the end of the pipe, so to solve that challenge and to create a more visually interesting gun end, a notch was created in the PVC pipe wide enough to accomodate the laser vertically with it's offset laser opening now centered in the pipe's opening. Then, the cut end of a black plastic trash can with a hole cut in the bottom is added to the end of the gun along with a ring of near-UV LED's mounted around the laser opening.

Step 3: Wiring the Chasing LED Treads

To give the suggestion of movement, the tread facings incorporated a chasing LED effect using UV LED strips. I purchased spools of UV LED tape from Ebay:
http://goo.gl/AuAMfB
The connectors are 2.1x5.5mm Jack DC Power Adapter typically used for CCTV Camera installations available on Amazon, Ebay and elsewhere.
I used a 4 channel portable theatrical dimmer pack to chase the lights, but there are many options for 4 channel chasing devices varying significantly in price. They could also be controlled by the lighting operator via DMX.

Step 4: Transport & Assembly

With an open framework on the tread sections, there was enough room to place smaller components within them, like the foam wheels.

Assembly went problem free and fairly quickly. Check out the photos and notes to see how it all went together on-site.

Other resources:
Wildfire UV paint:
http://www.wildfirefx.com/products/paints/index.as...
UV laser: prices on these have dropped significantly, and are becoming harder to find. Possibly because of their lower visible spectrum. They however activate fluorescent items brilliantly.
http://goo.gl/vduyTD