Deadlights While Waiting

The bulk of my window shopping was done in 2 shots at the local auto salvage yard, but I still wasn't able to find all the windows I wanted to have. The problem is the strict size limit of the camper. Due to the shape of the walls and how they curve up to the roof and the limit of space between the structural frames, well, any windows would have to be pretty small and flat.

The plans I started this with suggested fixed small windows like portholes - also known as deadlights. So ok, let's make some deadlights.

I have a 6" diameter hole saw left from my grill project, so I decided to make that the basis upon which these windows are based. A 6" hole means about 6.5" bolt circle and so a 7" or so overall diameter of the window. So I whipped up a quick template in autocad, printed it to scale and cut some blanks of lexan or polycarbonate. With some spray adhesive, I laminated 2 sheets at a time and tossed them on the mill. Now, step 1 of a job like this is to drill out the blanks so they have a common mounting pattern. You'll see why.

Blanks stacked with the template placed on them to approximate where the center should be. The center finder (tool in the chuck) is a fine point and the mill was zeroed to its location. 

7.5" bolt circle drilled into the stack of blanks. I want 4 windows total plus a  hard template to  mark the bolt circle onto the camper sides. The 3rd sheet of lexan is sacrificial. It's there so I don't drill into the table.

 

A sacrificial plate of aluminum is clamped to the mill and the template placed on it to locate a reasonable center.

So my plate has a known origin (0,0,0) Cartesian Coordinates FTW! I make a 7.5" bolt circle here, too, only I don't drill clearance holes. I drilled the tap drill for these #10-32 studs threaded into the plate. 

I used standoffs instead of nuts to hold the blanks down while they're milled. This is  that same bastard endmill that ripped open my finger, but here I'm using it for good instead of evil.

A closeup of what's basically a cleanup pass, where the top edge of the windows are knocked down to a 45 degree chamfer. The cutter gets a little close to the studs, so I had to remove the standoffs as the cutter moved around the windows.

Here is 1 of the 4 deadlights. The holes were drilled out to 1/4" and these aluminum bits are pressed in. These are screw barrel posts. These are cool because they're blind and therefore waterproof and they're slightly longer than the windows are deep. So with my template, which looks like this only no hardware and a final clearance hole in the center of the circle, I can mark and drill the bolt circles in the walls as well as the pilot hole for the 6" holesaw. Then I'll RTV the edge of the windows, stick them in place and screw them down from the inside.

Now all I need are walls.