I was inspired by Toeglo for this project. It's a great product and if you don't want to make your own, you should buy from them. Theirs is undoubtedly more professional than mine (mine has a lot of light leakage, but the overall effect is quite similar).

I wanted one for my upcoming Halloween party, but they exceeded my budget so I decided to make my own. It's relatively inexpensive (under $30) and takes about 1 hour to assemble.

Hope you take a chance and make one. They are really, really cool!

Supplies

1 x Red/Green Laser Party Light (around $25)

1 x Glass Stirring Rod (around $8)

Hot Glue Gun

Dremel

Pliers

Screwdriver

Step 1: SAFETY WARNING!

Working with lasers can be safe if you take the right precautions.

Do NOT stare into the lasers
Do NOT work with it around children - their eyes are table height and they could accidentally get the lasers in their eyes
UNPLUG everything before working making any adjustments

That said, I didn't wear any special glasses or anything. These lasers are pretty low powered. They do not heat up if you place your hand in front, for example. However, take whatever precautions you deem necessary to protect yourself.

Step 2: Disassemble the Laser Party Light

Most should be similarly built - take off the front cover.
Make sure to take pictures of the connections before you pull everything apart.
Unplug all the components.
Remove the filter disc, the motor, and any extra components aside from the lasers.

Step 3: Cut Out the Laser Housing.

I wanted to reuse the housing, but if you have access to a laser cutter or 3D printer, you could easily remake a smaller, more precisely assembled housing.

I chose instead to cut out the plastic frame that holds the two lasers parallel.

Step 4: Hot Glue the Lasers Inside the Housing and Modify the Lid.

Since hot glue didn't stick well to the metal, I put down some masking tape to help give it something to adhere to. I glued the lasers back into the housing, making sure to recess it back about 1 cm so that there's room for the stirring rod and lid.

Mark out where to cut the lid using a dremel tool. It doesn't have to be precise - I just eyeballed it. Then assemble the plastic frame that hold the electronic PCB in place. Do a test fit and cut away any material that might prevent it from sliding back into place properly.

Step 5: Break Off a Piece of the Stirring Rod

I tried using a glass cutter to score it, but it was just easier to wrap it in masking tape and then using a dremel to lightly score its circumference and then break with some pliers. It doesn't need to be a clean, straight break, but obviously try to do a decent job of keeping it flat.

You'll need 1 piece for each laser. I broke off about 2 cms.

Step 6: Gluing the Glass Rod and Aligning the Laser Beam

Before you glue the rod, use the remaining long piece to understand how it will shape the light. The roundness of the piece will spread the laser into a line. Moving the rod left or right will determine if it throws more to the right or left. In this way, you can have the red laser throw more to the left and the green laser to the right or have them overlap.

This can create a cool effect if you set the lasers to turn on and off randomly - sometimes your feet will glow green, sometimes red, or it stops glowing for people on the left or right. I chose to overlap a little, but wanted a defined red and green zone.

If you angle the rod forward, it will cause the line to bow in one direction and backwards in another - the goal in this case is to create a line that doesn't bow at all.

I started by laying the Laser Party Light flat on the table. Where the beam hit the wall, I placed a piece of tape to mark.

I then put a large blob of hot glue in front of the red laser. I quickly placed the first piece in front and checked alignment by rotating the housing. As long as the line doesn't rise or fall too far from the mark, it should be good. Make adjustments as necessary. Then, repeat the procedure for the green laser making sure they both hit at about the same place. Reinforce the rods by adding glue to the top and bottom, making sure not to cover the laser.

Step 7: Place the Laser on the Floor and Align It

Replace the cover making sure the electronics are secure. You can use the mounting bracket to help you with floor alignment. Start with it bent and pointing down at the floor. Then slowly press down on the housing which will cause the laser to rise. The goal is to have it just trace the edge of the room.

Now you can have a laser floor party!!!