if you are just looking for a 45degree offset, meaning you are just trying to have it move on a 90degree or 180 degree plain. the calc. is your number x 1.414. if you are looking to roll the offset to a 45 degree off center and it be on a 45, the calc. is you number x 1.414= sum then sum x 1.414 that gives you the roll of a 45 and offseted to a 45
on a rolling offset you will want to use a formula learned in geometry. being a plumber and pipefitter i do this on a daily basis. for example draw a circle at the top of a piece of paper, then draw one at the bottom on the opposite side from where you drew the top circle. now the rolling offset is going to be the piece of pipe in between the two circles. so lay out an imaginary line that travels from the bottom circle straight up the paper till you run out of paper.do this from the center of the bottom circle.then draw a line from the center of the top circle over to the line that you drew from the bottom circle until they intersect. this line will run horizontally. now get the center to center measurements for both lines.use pythagory and theorem. a2+b2=c2.c being the line you are trying to find.when you have that answer minus the end to center of both of the 45 degree fittings. then take that number and times it times 1.414 which is the 45 degree formula.the number you get is the answer to the length of pipe that you need to cut.BAM there it is.
All this (1.411) & (1.41) is fine if you are a 1st year apprentice LMFAO !!! NOW I will show you the right way to do a "PYTHAGOREAN THEOREM", I know all of you that read this are the BEST PLUMBERS & PIPE FITTERS IN THE WORLD, but it's time to eat a big piece of HUMBLE PIE !!!!
1st thing the correct 45 degree offset calculation is 1.414 PERIOD; However on a rolling offset
That has nothing to do with that calculation ( HYPOTENUSE ). This also applies when figuring the TRAVEL that isn't a perfect 45. 1 guy said. " A^2 + B^2 = C^2 ", and that is correct for instance 14' run & 9' rise, but not for a rolling 45 degree offset, that's only to get the travel for a formula that you can't use a true 45 or 22 1/2 bend, and you have to make your own fitting, for instance 14' squared = 196 + 9' squared =81, so 196 + 81= 277, now 277 squared is 16.64331 feet or 16' 7" 3/4, that's trigonometry, and if you want to be the best you can in the pipe trade you must learn it. 1 guy said get the (PIPE FITTERS BLUE BOOK), and yes if your a plumber or fitter all these formula's are in there get it from Amozon for $20, it's worth it; oh yeah actually read it, until you understand it, it took me a few times, for it to click and I'm still learning, my apparentice asked my " how to do a rolling offset" so we looked it up and I SH!T myself laughing when I saw some off the answers, not that there all together wrong just not quite all together on point. I'm sure these guys are great pipe fitters & plumbers, I'm a plumber 20 years & been pipe fitting and ship fitting for another 10, now I'm on the welding side, lots of down time unless I have 4 fitters going like hell. I'm still learning there are so many aspects of pipe installation and layout, but most guys don't know the difference between a P-Trap and a J-Bend. Lol
Keep learning it never ends once you know it all your done..
Now for the true formula for a 45 degree rolling offset
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Square the pipes' offset. For example, if 12 inches separate the two pipes horizontally, square 12, giving you 144.
Square the pipes' rise, which is the vertical distance between them. For example, if this rise is 11 inches, square 11, giving you 121.
Add the two squares together. 144 plus 121 is 265.
Find the square root of the sum. The square root of 265 is 16.28. This is the size of the pipes' true offset, which is the perpendicular diagonal that joins the two.
Find the trigonometric cosine of the angle of the fittings you plan to use. For example, if you use 45 degree fittings, the most common kind, note that the cosine of 45 is 0.707.
Divide the true offset by this value. With this example, 16.28 divided by 0.707 gives a rolling offset of just more than 23 inches.
Dedicated to Howard Delima's Plumbimg in Hilo Hawaii
And of course Don Nakooka the 3rd best plumber in the world who made me want to be better than him.
Does anyone know what the rolling offset would be for a 45 degree pipe fitting going up 3-7/8"
How do you figure out rolling offsets?
It looks like you are trying to figure a straight offset, in that case you figure 3.875 x 1.414 = 5.479 or 5 7/16 " don't forget that this is a center to center measurement. So take off for fittings. If you are trying to figure a rolling offset it would be figured as follows; assume that the offset is 12" and the rise is 8" 12x12+8x8=208 find the square root of 208 which is 14.422201 then divide by .707= 20.399152 or 20 3/8" for the travel piece center to center. hope this helps.
Take the two square measures in between the pipes for example horizontal is 10" and vertical 20"squaref course it could be also back to front and side to side then take a steel square and mark 10" in one side and 20"on the other side of the square, take measure across the marks and multiply that by 1.414 for the 45° do the take out for whatever size of pipe and that will give you the length of the pipe in between the two elbows then just build the piece like a straight offset and put it in rolling the whole piece until it fits if the lengths are more than 24" which is the length of a steel square then just paint a perfct square and extend it.