rolling offset

[Ivan Young]

I believe this topic has been beaten to death, but I have a question.
Say the vertical is 12" and the horizontal is 6". You square both numbers and add
them. So that would be 144 + 36=180. Square root will be 13.42. Now the question is
this, are the marks going to be 13.42" apart or do you have to multiply this number by 2
if you are bending a 30 degree offset?
Thanks for any help.
Ivan

 

[infinity]

Your offset is 13.42" just multiply that by the proper multiplier based on the angle you use.

 

[Ivan Young]

Thanks Rob. So for 30 degree it will be 13.42 x 2=26.84. For 45 degree
it will be 13.42 x 1.414=18.98, etc.
Thanks again.
Ivan

 

[infinity]

Yes, that's correct. You first find the size of the offset taking into account the amount of roll and the height by using the Pythagorean theorem, then multiple by the correct constant for the angle you're using. If you didn't have a calculator you could use any square cornered object like a pull box cover or a door buck to measure the offset with the roll factor. Just make two marks out from the corner, one for each dimension, and measure across.