This project will be rather simple, since we're
working with a perfect circle, not an elips. So the first order of business
is to make a big compass. My total diameter needed is 74-5/8" so the radius
or length of my compass will be 37-5/16". Obviously your dimensions will
be different!
At one end we'll have a high tech pivot point....
.....and at the other end, 37-5/16" away i drill a hole
for a pencil. While I'm at it, I drilled a hole 3-1/2" away, the width
of the trim. Drill the holes so the pencils fit snuggly.
Be sure the pencils and the pivot all in line, this will
be important later! My compass is 2" wide, so i drilled my holes in the
center
After testing the cumpas for accuracy, start
laying out some curvesd! I needed 3 pieces for mine, but i made 2 extra
in case i screwed up!
It takes a little finagaling to get both pencles to contact
at the same time. hold onto the compas, not the pencils as you mark your
pieces.
Just another view from the other side. My bench is large
enough to make these pieces, but I will need to lay out a sheet of plywood
when I assemble the pieces.
save the compass so you can use it to draw a full sized
pattern on the plywood. This will aid in getting all the joints at the
right angles.
Ok, so how do we lay out the ends of our curved
pieces? Well since the pencils are drilled in the exact center of the compass,
we can reasonably assume the pencil points will point back to the center
of our arch.
So If you put a steel rule against the pencil points.....
.....you can draw a line that should be pretty close
to perfect!
.... and my ossilating drumsander to clean up the insides.
Remember this piece is going to be about 25 ' in the air, no one is going
to be doing any detail inspections, I'm the last person who will see this
piece up close!
Now to rough cut the pieces, i use my fingers
between the fence and the stock to hold it roughly at the proper angle.
Next take your pieces over to your plywood pattern to
tweek the angles so they fit and stay on the pattern.
With the Pieces "tweeked" with new cutt off lines, you
can either go back to your chopsaw, radial arm saw or disk sander to make
the final adjustments.
Next I cut some biscuit slots to help keep the pieces
flush with each other......
....and then drilled some pocket screws to pull
the joints together, and secure them permanently. Since I made this trim
with Azak pvc plastic, i used pvc cement at the joints. But I suppse that
wasn't really necessary.
Ok, all this work and heres why! Both sides of
the trim are rotted where they meet the sill. I have already replaced the
sill with a plastic one provided by the window manufacturer. Now its just
a matter of cutting the painted joints with a utility knife, and pulling
the nails.
I made the trim long on both ends. After test fitting
the trim i was able to layout the new cut lines, notice the angle where
the trim rests on the sill.
Now that doesn't look to shabby, eh? And the
customer was thrilled!
And yes, I washed the window when i was done!
Remember I said no one would notice if it wasn't
perfect? It's ok if things are off a little, only you will know!
