Originally Posted by nbynw
So my questions: what are the optimal dimensions for the port? What is the optimal vertical and horizontal placement for the port? I may be constrained horizontally by wall studs and would prefer just to fit the port between them - easiest solution if viable.
I guess optimally the smaller the better, so it would be best to have an idea of how far back your projector can sit and still get proper ventilation. Then it's a bit of triangle geometry to figure out if the projected image will clear the port.
What I did instead, is kind of let the dimensions of my glass determine the size of the port hole. A lot of people around here recommend getting proper optics glass, which will have exceptional clarity, and minimize reflection. That being said it's still a good idea to angle the glass 10-15 degrees to avoid reflections going back into the projector. This is what is recommended a lot from my experience:
That is part number 43-974, if the link stops working sometime in the future.
It's an 8x10" sheet of glass.
For my port I planned on a 15 degree forward angle, and then due to measuring inside on both measurements, I wound up with about a 12 degree angle, which should also be fine. I got some 3/4" birch for mine, and then used a table saw and the little angle compass thing to cut the inlet to depth, at the proper angle (this was challenging, and yeah, I might have had to redo once or twice). I cut it about 1/4" deep, and then used quarter inch thick weather stripping to seal as well as i could around the glass. When planning the height and width of the port, I cut it about 1/4" shorter than the glass. The inlet, plus that cut, plus the stripping means it stays tight, compressing the stripping around 1/8 on each side. Attached some pictures to help explain a bit.
I plan on having another layer of wood on the outside to kind of help "seal" the port into place against the drywall.
Edit: although according to mhutchins, I might need to reconsider my forward angle.. luckily I can just flip it around to get a minus 12 angle. Might need to draw it out similarly to get an idea of reflections.
Edit Edit: Also regarding placement, creating a box in the framing so that you have the port centered isn't too big of a deal, especially for new construction. It's essentially just a slim window framing up high. If you already have drywall, it's a little more tricky, but not impossible.