Tripod for RPG mapping projector: First prototype

While I wait for the projector to arrive so that I can begin putting digital maps on my game table, I decided build a prototype of my tripod idea.  Here it is in all its glory:

I don’t plan for this to be the actual version that I use, of course – this is more of a proof-of concept.  And of course it looks a little bit silly with no projector, but I put out a Chessex mat, some tokens, some dice and some character sheets so that I could get a feel of what it would be like to play with it.

First, I’ll tell you what I did.  I started with two eight-foot long pieces of cheap pine (1/2 inch by an inch and a half) that I bought for 77 cent apiece from Home Depot.  I cut each of these in half with a miter saw, ending up with four pieces of wood, each 48 inches long.

I then took a big piece of scrap plywood that I had laying around (it was about 30 inches square to start with and 1/2 inch thick), cut it in half and then cut one of those halves in half again an a table saw, leaving me with a 15 inch square.  I then cut this into a 15 inch equilateral triangle (yay geometry!) on the table saw and drilled a hole in the middle using a hole saw.

Next, I drilled pilot holes for mounting the hinges on the underside of the middle of each side of the triangle as well as at the top of each leg.  I also drilled pilot holes roughly eight inches down each leg for the screw eyes.  I screwed the hinges onto the triangle and the legs, and I screwed the screw eyes into each leg.  I then threaded a piece of kitchen twine through the three screw eyes and tied it to close the loop.

When I set this version up, it was too tall (as I knew it would be), so I shortened the legs to 39 inches each using the miter saw, which left the platform 36 inches above the table top (I’ll probably shorten it to 30 inches in the end, but I can always cut it shorter – I can’t make the legs longer). I also tightened up the twine a little bit from my original pass.  What you see in the photo above is the result of this work.

What’s the verdict?  Well, I’ll admit that I’m having serious doubts about this approach.

  • The hinges have a lot of play in them, which means that the platform can be a little wobbly even if the legs are securely stuck to the ground.
  • The legs, as I feared, are a little awkward for the players to reach around.  They WILL be bumped.
  • While the twine keeps the legs from pulling father apart (and yes, I was planning on using something sturdier than cotton twine for the final version – probably leather string), it doesn’t keep them from being bumped closer together.  That could still cause a collapse if a leg gets shoved inward.

I’m considering a few different options from here.  First, I will play with this prototype a little bit more to see if it might be worthwhile.

  • I’ll try wrapping some duct tape around the hinges to give them less play.
  • I’ll try using some kind of rigid brace between the legs, either wood or metal.  I’m thinking of something like a really long hook and eye, like you might see latching a cabinet or screen door closed, but the longest I’ve found so far is only six inches, which doesn’t stretch far enough.
  • I’ll put some bigger feet on the bottom of the legs (probably four inch squares of plywood), which might give me the chance to clamp them to the table.  I also plan on putting some rubber on the bottom of these feet.

However, I’m also open to the possibility of completely abandoning the tripod idea (which is why I just build a quick and dirty and cheap prototype first).  Some folks on EN World have pointed out that I don’t have to have the lens of the projector mounted over the center of the table, since the projection angle doesn’t spread equally downward and upward from the center of the projector – it spreads mostly upward.  This opens up possibilities such as a single pole with the projector mounted to the top of it, perhaps clamping the pole to the table.  My wife also suggested just using a metal sawhorse and mounting the projector to the side of it, which might totally work.


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