# 45 offset



## moonapprentice (Aug 23, 2012)

Anybody know the trick or the thread for the 45 offset formula using a tape measure.

Tried looking for it and can't find it.

I remember trying it out a few times and it was fairley accurate, but forgot how to do it. This is probably wrong, but It involved something like counting a certain number of eighths on your tape measure after a set measurement and that was your piece (not including make up or take offs). Basically no 1.41s or calculators involved. It was all done counting on your tape


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## wyrickmech (Mar 16, 2013)

Why not just use the formula? Or just by the Franklin book it's got cheat tables in the back.


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## rwh (Dec 17, 2014)

I know the second joint measurement for a 45° angle on a stick rule. Also in Frankland book. Many here won't know what a Frankland book is.


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## ShtRnsdownhill (Jan 13, 2016)

https://www.amazon.com/Pipe-Fitters-Welders-Handbook-Revised/dp/0028025008


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## moonapprentice (Aug 23, 2012)

Yup, have that book, is very informative. I do use the formula. The tape measure trick I forgot, just seeing if any one knew that one


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## rjbphd (Feb 5, 2010)

moonapprentice said:


> Anybody know the trick or the thread for the 45 offset formula using a tape measure.
> 
> Tried looking for it and can't find it.
> 
> I remember trying it out a few times and it was fairley accurate, but forgot how to do it. This is probably wrong, but It involved something like counting a certain number of eighths on your tape measure after a set measurement and that was your piece (not including make up or take offs). Basically no 1.41s or calculators involved. It was all done counting on your tape


I use the FR tool..


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## Dave C. (Jul 7, 2016)

ok its the measurement plus 1/2 minus 1/2 1/8"
so lets do a 20" offset
20" +10" =30"
30" -15/ 1/8"(1 7/8")
=28 1/8" 
it is close but not highly accurate
20 x1.414=28.28
plumbing is a mathmatical science and should always be treated as such,and not taken lightly,i suggest not using this method as it tends to provoke weakness and lazyiness


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## rjbphd (Feb 5, 2010)

Dave C. said:


> ok its the measurement plus 1/2 minus 1/2 1/8"
> so lets do a 20" offset
> 20" +10" =30"
> 30" -15/ 1/8"(1 7/8")
> ...


Where's Old School on this???


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## Dave C. (Jul 7, 2016)

rjbphd said:


> Where's Old School on this???


Old school what?


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## rjbphd (Feb 5, 2010)

Dave C. said:


> Old school what?


One of the original member of this site.. some of us old timers here know where he went..


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## Plumbus (Aug 4, 2008)

Another fine book on the subject.
https://books.google.com/books?id=C...en#v=onepage&q=rolling offset formula&f=false


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## rwh (Dec 17, 2014)

Plumbus said:


> Another fine book on the subject.
> https://books.google.com/books?id=C...en#v=onepage&q=rolling offset formula&f=false


Ooooh, a rolling offset! Who can figure one?


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## moonapprentice (Aug 23, 2012)

wyrickmech said:


> Why not just use the formula? Or just by the Franklin book it's got cheat tables in the back.


I do use the formula. All the time! No eyeballing for anything. I just remember their was a post on here somewhere I can't find about using the tape measure to figure it out. Doesn't necessarily make that right, but just want to know it anyways.

I'm also surprised at how many plumbers eyeball, guess, and cut, cut, cut. Not for me. One and done and accurate. I am educated on rolling offsets and parallel as well. Not just 45s either.

I just thought the tape trick was interesting and forgot, that's all.


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## moonapprentice (Aug 23, 2012)

Dave C. said:


> ok its the measurement plus 1/2 minus 1/2 1/8"
> so lets do a 20" offset
> 20" +10" =30"
> 30" -15/ 1/8"(1 7/8")
> ...


I actually think there is more time involved, takes longer. And not "true",but a really close ballpark. 

Doing the math is faster and more accurate. 

I just forgot how it went, probably won't use it, (i forgot it cause I didn't use it). Just good to know tho, that's all


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## Fatpat (Nov 1, 2015)

Dave c is dropping knowledge.


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## Dave C. (Jul 7, 2016)

rwh said:


> Ooooh, a rolling offset! Who can figure one?


 

ROLLING OFFSETS
ok well anybody who has ever had to lay a job out, knows this is easy with a caculator because of the square root you need to find your true angle to be applied
offset squared + rise squared x fitting constant wheter 45 22 1/2 or 60
the square root solution for the true offset gives great accuracy than the usaul layout method. however the layout solution should be practiced and is preferred because it gives a usable answer without finding square roots


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## Debo22 (Feb 15, 2015)

moonapprentice said:


> Anybody know the trick or the thread for the 45 offset formula using a tape measure.
> 
> Tried looking for it and can't find it.
> 
> I remember trying it out a few times and it was fairley accurate, but forgot how to do it. This is probably wrong, but It involved something like counting a certain number of eighths on your tape measure after a set measurement and that was your piece (not including make up or take offs). Basically no 1.41s or calculators involved. It was all done counting on your tape


http://www.plumbingzone.com/f3/about-me-56601/index3/
This one? Post #24


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## moonapprentice (Aug 23, 2012)

That's it's Debo! How the he'll ya find it?!


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## Debo22 (Feb 15, 2015)

moonapprentice said:


> That's it's Debo! How the he'll ya find it?!


Advanced search, typed tape measure offset. There were three to choose from.


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## Dave C. (Jul 7, 2016)

its like an internet echo (hello........hello)


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## Michaelcookplum (May 1, 2011)

The only thing about this formula I never ever ever understand is what is the fitting take off? Can someone draw a pic or just tell me what the fitting take off is for :
11/2"
2"
3"
4"

Thanks


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## wyrickmech (Mar 16, 2013)

Michaelcookplum said:


> The only thing about this formula I never ever ever understand is what is the fitting take off? Can someone draw a pic or just tell me what the fitting take off is for : 11/2" 2" 3" 4" Thanks Sent from my iPhone using Tapatalk


 it's simply from the end of the pipe in the hub of the fitting to the centerline of the fitting. Butt weld fittings a re simply from the weld to center.


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## moonapprentice (Aug 23, 2012)

It varies on what brand and type of material since each fitting is different
You would measure from the center of the fitting to where the "home" part of the hub is.
You can measure it by hand or get a fitting book specific for that brand and material and would say in there.

Recently on a Charlotte pvc 2" 45, the hub depth changed from 3/4" to 7/8". So I wouldn't take it for granted that the takeoff would be the same throughout your career if manufacturers are changing fitting dimensions here and there. But for the most part it is consistent.

Pretend your offset is a straight line going through the fitting. You would subtract the difference from the point the line changes to a 45 (middle of fitting), then SUBTRACT the void space from that point to the hub.

A different way of getting your piece is you could stack a 45 on another 45, take your center to center, get your offset, then ADD the hub depths too


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## Michaelcookplum (May 1, 2011)

wyrickmech said:


> it's simply from the end of the pipe in the hub of the fitting to the centerline of the fitting. Butt weld fittings a re simply from the weld to center.




Center line which way? Like where you putting the tape from the end of pipe to what center line? Following the 45 angle to center of where fitting turns straight? See this is why I never fully get it. Can someone measure tomorrow Charlotte Pvc fittings and tell me or I need a pic. Please and thanks. 


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## Bayside500 (May 16, 2009)

http://www.charlottepipe.com/Documents/DimensionalCatalogs/Plastic_Pipe_Fittings_DC-DWV(609).pdf


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## Bayside500 (May 16, 2009)




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## moonapprentice (Aug 23, 2012)

"A" Would be the take off. Once you understand it Mike you will love it and plumb offsets like there nothin. Master that, then there is only one more process to figuring out the rolling offset. Hope this helps. Dead nuts everytime!


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## moonapprentice (Aug 23, 2012)

Draw 2 straight lines on the fitting with a pencil, and where they intersect will be the middle (like the picture) if you don't have books to look at. Hope that helps some


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## Michaelcookplum (May 1, 2011)

Bingo! Thank you! I got it! Will practice next week!


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## rwh (Dec 17, 2014)

Wtf


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## Letterrip (Jul 28, 2013)

Bayside500 said:


> http://www.charlottepipe.com/Documents/DimensionalCatalogs/Plastic_Pipe_Fittings_DC-DWV(609).pdf




I have this saved on my phone in iBook. (iPhone. Android will be something different). Flip through it on the job when I'm out of practice. Do it a little and the numbers start coming back to me. 


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## mtfallsmikey (Jan 11, 2010)

rjbphd said:


> One of the original member of this site.. some of us old timers here know where he went..


 I'm both old and old school... still have a Lufkin folding plumber's rule, offsets were easy with them... 

https://www.amazon.com/Lufkin-626LN-Plumbers-Wood-Rule/dp/B00LHM58ZW


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