Monday, November 12, 2012

rafter - cutting the bird mouth joints

Since the lap joint's were done yesterday, it was time to cut the bird mouth joints today. As preparation of assembling the roof tomorrow

First how does a bird mouth joint look?

standard birth mouth joint
The next step was to calculate the approximate position and our old friend Pythagorus came to the rescue, since our roof is going to have 90 angle at the top.

a*a + b*b = c*c
And since our dog house is 42" wide, the approximate position of the joints should be around 30". I'm saying approximate since we also have to include the width of the saw blade (slowly learning....) and that our fence is not that precise.

cutting the miters on the table saw
 The first step was to cut the miter on the table saw, while utilizing a block of wood with a clamp as a stop to ensure that all the joints are cut at the same position.

a bit wide
 Now the first cut was just a bit wide and since we did this in batches it meant that all rafters were a touch to wide. Not a big problem, since the joint needs to be on a double top plate anyway and so we just going to cut the top plate a touch wider.

finished joints
And there are our finished ratfters, with two bird mouth joints each, a lab joint and cut to size. Still not sure what todo with the ending, if I leave them at they are round them over. And how to put the wooden planks on. Maybe cutting some rabbits or so.