Dropping the Hip?

[chirpychippy]

Good Morning,

Just a quick question please, when calculating the amount to drop the hip by, is the calculation based on half the 45 degree thickness of the hip or half the 90 degree thickness of the hip.

I have a 2 3/4" thick hip for degree pitch 10/12.

At 45 degrees it is 4 1/8" so half of this is 2 1/16" so....... forget the 16th

Rise = 10"
45 degree = 2"
Run = 16.97"

10 x 2 = 20
20 / 16.97 = 1"3/8 drop

Is this correct or is there a simpler way of working it out, any help will be appreciated as its doing my head in.

 

[mcluma]

YES

use www.blocklayer.com - it does it all for you - its free. and you can print all the plans -and its good. i have used it a many a times

 

[KenGMac]

It may be you need to look for the Dyhedral Angle calculations?

 

[chamfer]

I asked the same question not that long ago http://www.diynot.com/diy/threads/cut-and-pitching-roofs.435163/