• Coffee Table
  • Day 1
  • Day 2
  • Day 3
  • Day 4
  • Day 5
  • Day 6
  • Day 7
  • Day 8
  • Day 9
  • Day 10
  • Conclusion
• Whiteboard

Day 2

Building the Mounting Frame

It was far too hard to juggle the stacks of boxes and slide the mirror around whilst balancing and lining up the projector with the mirror and screen and so construction on the mounting frame began after cleaning my local hardware store out of all of their slotted angle iron still leaving me short and with a few mismatched for the lengths I needed.

I reused the roof mounting bracket for my projector to mount the projector to the cross piece. Unfortunately due to the lack of materials I was unable to stabilise it with a front beam and second pair of risers.

Now that the projector was mounted I decided to check the alignment of the projection relative to the end panel of the frame. I temporarily clipped a spare sheet of the drafting film to the end of the frame, the verticals are 60cm high and since my intended height for the screen is ~42cm the projection needs to fall quite a distance by the time it reaches that sheet. The projection was pretty square for an initial test and so I moved on to installing the mirror.

The frame on the mirror I purchased gave it a 5cm border and just got in the way so I had to remove it. Many staples later I finally had gotten the mirror glass out of the frame and clamped it to its backing board to make it a little easier to handle.

As I mentioned earlier the mirrors horizontal profile, since it is on 45 degrees, is only 42.43cm. I added a cross support in the base below the screen so that the mirror cannot slide forward into the front 18cm ensuring that while it's leaning up against the front most vertical supports that it sits at a near perfect 45 degree angle.

Now that the mirror is in place it was time for another check of the alignment. Since know that the projection at the back panel is approximately square we know that if it's miss aligned on the roof then the mirror is not aligned correctly. (Bear in mind however my roof is on an incline)

And now the final piece for the display, putting the assembled acrylic screen onto the mounting frame. A bolt through each vertical screen support prevents the screen from falling down onto the mirror and allows for adjustments if necessary to make it level.

Now that it was all in place it was time for a projection test and a bit of tweaking to get the angle of projection, focus and alignment correct. The cross section that the projector is mounted too isn't as stable as I'd like so the image isn't as well aligned as it could be. The build does go far enough to show that it'd all work out well and it aides me in measuring everything out for a final design perhaps cut from MDF.

Overall not too bad for two days work including the gathering of materials and the testing of concepts.