Introduction: Free-Standing Cantilevered Rear Projection Screen

It is nice to have a big screen for the scoreboard at Roller Derby bouts but there are many obstacles. My first design was too big to fit in the space allowed and took quite an effort to transport/setup.. My second design fit in the space well and was easier to transport/setup but was still cumbersome. Inspired by Sun Shade, I set out to improve on the screen by providing sizing flexibility and making it easy to transport/setup.

Goals for this design:

  1. 10' x 10' screen
  2. No structural part longer then 6'
  3. Adjustable projection distance up to 15'
  4. Stored in 3 manageable containers

Why cantilever? For the safety of the Roller Derby skaters. The screen can be close to the action without being a hazard to a skater.

Thanks for looking!

Step 1: Materials

Most of the materials were selected from stuff I had available.

  • Black iron pipe (various lengths and diameters)
  • Wood rod
  • PVC pipe and fittings
  • Plastic sheeting (clear for the screen, black for the cover)
  • Pipe clamps
  • All thread rod
  • Trash cans
  • Concrete Mix
  • Tarp clamps
  • Elastic cords
  • Tie-down straps
  • Pin-and-Clip

Step 2: Building the Base

The base of the structure will use three points. Two of the points will allow the cantilever to pivot to facilitate the screen setup. The third point will anchor the cantilever and provide a platform for the projector. The all-thread at the base of the posts will help stabilize the post in the concrete at the bottom of the trash cans. The cantilever posts have been drilled and pinned so the cantilever post height can be adjusted as needed. After the posts have been prepared, the concrete is mixed in the trash can and the post inserted. I used the lids to help keep the post in place while the concrete cures.

Step 3: Building the Cantilever

For the cantilever to be flexible to accommodate differing space requirements, I want to be able to adjust the length of support between the posts and screen independently from the support between the posts and the anchor. I also want to allow pivoting at the post and minimize weight of the structure at the top of the posts. The pipe clamp connectors used in chin-link fence applications provided the solution nicely. Using wing-nuts helps keep the tool requirements to a minimum. The tie-down straps connect the support structure to the anchor and make it easy to raise and lower the screen during setup.

Step 4: Attaching the Screen

The screen is attached using tarp clamps. These worked well in the previous designs and provide some ability to tension the screen. I also use paper clips to connect the cover and screen to provide stability and a clean edge to the outward appearance.

Step 5: Test

The screen worked well in spite of the wrinkles. As usual, the setup time was cut short and I didn't get to tweak the surface as much as I would have liked. I think I can get a smooth face in the future.

The design met my expectations as the transportation and setup was smooth and quick. The rolling trash cans made it easy for volunteers to roll off the truck onto the dock and then into position. The cantilever fit well in the space allowed and eliminated the need for a step-ladder during setup/take-down.

I hope this inspires you! Thanks for looking!

Optics Contest

Participated in the
Optics Contest