And in the physical world...

Quite a bit of the content in previous posts have focused on the software side of things, but in reality, this project has just as much going on when we look at the physical side of things.  After all, there's gonna be a booth, with a table that people will walk up to, so today we worked out the finer details on how all of that will be handled.  Starting with a trip to Home Depot.

The surface of the projection platform will have to be sturdy enough to support the weight of all of the vehicles while also having enough friction for the wheels, and be a white surface for the projector to, well, project on.  Oh, and be cheap.  That too.  We settled on this large 4'x8' panel of some insulating foam panel of some sort.  It's lightweight, sturdy, and only $10.  Drywall was around that same price range but is relatively brittle and unnecessarily heavy.

With that decided, we moved on to the design of the projector mount.  Based on what we calculated, to resolve an image that is 4 feet tall by approximately 5 and a third feet long (maintaining a 4:3 aspect ratio to maximize the use of the projector's capabilities), the projector would have to sit 44 inches above the surface to be projected on.  Adding on the 29 inches for the height of the table, the projector lens would be placed six feet above the ground.

Drawing of the projector mount

The construction of the mount would be completed through the use of a popular framing

system called 80/20, and paired with the appropriate brackets, connectors, and screws.

The actual projector mount

To get the projector attached to the tall piece of 80/20, a plate was created from a sheet of plastic called HDPE.  After measuring the distances between the mounting holes on the back of the projector and transferring that data to the uncut sheet (through the magic of pencil markings on a sheet of paper and tape), the sheet was brought down to the garage where it was carefully cut using a method known as NHTCOOI.

Here's the result:

NHTCOOI = Neil hacksawing the crap out of it

With the plate cut and mounted to the eight foot length of 80/20, the projector was ready to be mounted.  For preliminary testing, the projector was set to 44 inches above the ground so that we could measure the dimensions of the final image and adjust the frame to make sure there was no skewing going on.

An accessory arm was also mounted to the structure, which will hold both the camera that will be used to track the vehicles, and the IR transmitter (effectively, an IR LED) that will act as the beacon for each of the vehicles so that they know where to go.

Lots completed today, and just in time, considering there's, uh, there's twelve days until the big event.  Ooh boy.  So much testing to do.