Here's an aluminum cart I'm making for my Everlast PT200DX that I got a couple months ago. It's built almost entirely out of stuff that was laying around from other jobs. The lower level of the cart will hold the water cooler setup I'm making. I also plan on putting a slide-out drawer somewhere for consumables. Sorry for the crappy pics, they were taken with my cell phone because my camera is having issues.
Base level and water tank. 5" heavy duty casters from shipwreck tools, and 10" solid rubber wheels which I had laying around.
2 Gallon water tank made from .063" aluminum. The aluminum tank will act as a heatsink which will help since I will not be using a heat exchanger.
Made a bung that will accommodate an automotive valve cover cap from Autozone. This cap will pop out if the tank should ever freeze. Also put on two 1/8" NPT bungs for the water feed and return.
1/2" allthread and nyloc nuts holding the wheels on.
Here is the water pump I'm using. It's a Shurflo agricultural diaphragm pump. It easily makes like 200psi if you let it. Maximum free flow is like 1gpm or something. This is a 12volt model pump. I've found that running it from the 3.3v supply from a computer power supply holds it right around 50psi through my 12' WP-20 torch. There are some issues that I will address when I install the system into the cart, more on this later.
Here are some tubes that will hold different types of filler rod.
Here you can see 2 short tubes welded on top that will locate the welder's rubber feet. Also, the filler rod holding tubes are bolted to the cart.
Here you can see how the ratchet strap mounts to hold the argon tank on.