The basic skeleton for each mobstacle is build out of these four way connectors, and 5' lengths of 1/2" PVC. We chose to use even lengths for easy assembly. The reason for the four-way connectors will be discussed later.
First start off with a template of one of the walls. You can do this with any 1/2" PVC connector to make a square. Lay your cloth, or whatever you're using for your walls under your wall template. You'll need a sheet 60" across, and at least 70" long.

Overlap the ends of the cloth around your wall template and pin them down.


Now it's time to sew that shit!

This is very time consuming and not fun. But it will be worth it. If you don't have adequate sewing skillz or a sewing machine, I suggest looking into getting these. They seem like they'd be the perfect thing. Also, if you're going with that option, it's a good idea to looking into buying tarp instead. It seems to be a lot cheaper per square foot than most, if not all cloth.
After you've made four walls, it's time to actually put it together. Here's what you'll need.

If you're making a basic cube, you'll need 12, five foot lengths of PVC, two bungee cords, eight 4-way connectors, 1/4"-3/8" diameter rope, and obviously your walls.
Make a cube. Face the four way connectors the same way on the bottom and top of the cube. You want them to face the same direction so you can add on walls to connect cubes to each other as your mobstacle collection expands. If you have the time and money, and the space, it's feasible to build an entire arena to nerf in.

Put on the walls

Now it's time to tension your walls. This will keep you mobstacle together.
Take the rope and feed it through the top of the frame. You want to feed it through one of the 4-way pieces.

This is also not fun, but trust me it's worth it.
After you feed the rope all the way through, you should have both ends coming out of one of the 4-ways.

Tie a loop on one end of the rope and feed the other end through the loop.

Pull the rope and feed the loop through the PVC and pull it until you've created nice tension between the pieces.

Now, take your bungee, and attach it to the opposite end of the frame. Pull the rope around the bungee and tie a loop while there is good tension on the rope. You might want another person helping you for this part.

Should look like this after it's done successfully.

Now make sure you duct tape the shit out of the bungees so people don't accidentally get diddled by them.

After you've done all of that, you have to do it again, to the opposite end of the cube. Also make sure to do the tensioning (bungee cord and string business) on opposite corners of the cube.
And after you did the other side, your mobstacle is complete.

Customize them, connect them to each other with walls, do what you'd like.
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