Hello and thanks for the video! I have a couple questions though. At 2:25 You have a 3D view slide. Formulas *3 and *4 show multiplication by 12. The step is correct. However. the reason is not because the Total Run A-B is 12' but because there are 12 inches in a foot. Therefore you need to transform decimal 14.42' and 15.23' into inches and then into feet-inches. Just like 2.5 hours x 60 = 150 minutes = 2 hours 30 minutes. And the second question is about the 2' overhang. This should extend the common rafter to 14.42 / 12 * (12+2) = 16.82ft. The overhang of the octagon hip will be longer than 2ft. It will be 2 / 22.5cos = 2.164. Therefore the total run will be 12.98+2.164=15.144 and the total length of the hip will be 15.23 / 12.98 x 15.144 = 17.77ft I am learning to build a gazebo, not much knowledge in woodworking so let me know if I missed something. But I just took pure geometry approach.. Thanks!
Max T Hi Max, Thanks for the comments. Regardless if the total run is 12' or is 14" (including the overhang), you can simplify by multiplying by the Unit Length (14.45 for Common, 15.23 for Octagon Hip). The result is in inches which I convert to feet/inches. However, if you find it easier to divide the total run by 12 to convert to inches before doing the math, that works too! Your math above is correct so you're on the right track. BTW, the VelociRafter DVD contains 60 pages of illustrations and formulas that I hope provides useful info.
Hello and thanks for the video! I have a couple questions though. At 2:25 You have a 3D view slide. Formulas *3 and *4 show multiplication by 12. The step is correct. However. the reason is not because the Total Run A-B is 12' but because there are 12 inches in a foot. Therefore you need to transform decimal 14.42' and 15.23' into inches and then into feet-inches. Just like 2.5 hours x 60 = 150 minutes = 2 hours 30 minutes.
And the second question is about the 2' overhang. This should extend the common rafter to 14.42 / 12 * (12+2) = 16.82ft. The overhang of the octagon hip will be longer than 2ft. It will be 2 / 22.5cos = 2.164. Therefore the total run will be 12.98+2.164=15.144 and the total length of the hip will be 15.23 / 12.98 x 15.144 = 17.77ft
I am learning to build a gazebo, not much knowledge in woodworking so let me know if I missed something. But I just took pure geometry approach.. Thanks!
Max T Hi Max,
Thanks for the comments. Regardless if the total run is 12' or is 14" (including the overhang), you can simplify by multiplying by the Unit Length (14.45 for Common, 15.23 for Octagon Hip). The result is in inches which I convert to feet/inches. However, if you find it easier to divide the total run by 12 to convert to inches before doing the math, that works too! Your math above is correct so you're on the right track. BTW, the VelociRafter DVD contains 60 pages of illustrations and formulas that I hope provides useful info.
Hi very nice video, my task is to build a 10 by 10 Oct deck and gazebo love the math
Muy agradecido por su aporte :)
question... If the run was 10 ft instead of 12 ft. would you still use 8ft. rise? or would you lower the rise? would it make the roof look odd?
Unit rise: rise/run, 8/12 = .666, 10' x .666 = 6.66' (6'- 8")
You may want to check out my vid "Common Rafters part 1 for an explanation.
No