pipe cutting template

OK, I will admit that I am a noob, and that the answer may be easy. That being said, here is what I am looking for:

I have these two pipes, one is 4" diameter (running horizontally) and the other is 6" diameter running at a 30degree from horizontal angle. eventually the two hit, and at that intersection I need to make the 4" pipe join to the 6"' pipe, which then continues on its merry way farther down the structure. So I can extrude the two pipes, and I can even make a union and then remove the excess of the 6" pipe, because what I am really looking for is: a cutting diagram for the joint where the remaining 4" pipe hits the 6" section. A cutting diagram for the short piece of a Y joint.

I can make this image appear on my screen, but I am then stumped as to how to unwrap the pipe into a flat section so that I can see the curvature of the cuts required in planar view, for the real pipe that I have on my shop floor. I tried to use a .lsp program that was presented on this forum bu a German chap, but apparently I am still messing up. Anyone have a simple solution for me?

Please send me your 3d-sample-file (in ACAD2002) and I will unwrap it for you (using my unfolding program - see http://www.black-cad.de)

Regards

from good ©old germany

Jochen

I've run into the same problem. I'm trying to make a full scale template of a 3D solid pipe. I know how to layout the template for two pipes that join on the same plane. My problem is that there are 3 pipes coming into the same point. I have a 3d solid of the pipe but, can't figure out how to unwrap it.

Thanks, Hop

I only know how to do this the draughtsman's way. Project rays from a circle drawn for each pipe and map the intersection points. I've made quite a few wrap-arounds to help pipefitters mark off pipes for cutting this way.

One thing to remember when working out cutting forms for pipework is that the schedule (thickness) of the branch dictates the true sinusoidal shape. It's the inside bore of the branch pipe that sits on the larger parent pipe remember, not its outside diameter. In other words the sinewave shape is based on the internal diameter, but the overall length is based on the outside circumference. Does that make sense?

So if you are saying the true branch angle is 30° (I think you are but you need to determine it), draw the larger pipe horizontal and the branch coming in at the true angle. The parent pipe is drawn to its O/D but the branch to its I/D.

Next draw the another branch square to the parent pipe, so you have an end view and a side view of the branch.

Next draw (semi)circles at the end of each of these branch pipes of the same diameter, and split them into an equal number of segments (eg 10°).

Project the segment lines from these circles along the axis of each branch pipe, and where it intersects the parent pipe curvature, project them along the axis of the parent pipe. Plot the intersection points where they intersect each other on the side view and add a spline. This will be a true side view of the cut shape.

Next, project the external circumference of the branch pipe perpendicular to the inclined branch, and divide it into the same number of equal segments as the circles you previously drew. Then simply map the intersection points you have just drawn perpendicularly back onto it and spline it. The resulting spline will be a fairly accurate development of the true shape between the two pipes.

Boro Nut

there is a program available for download that will work this out for you.

bike frame makers use it to work out profiles when joining two tube sections together.

i have not used it, only read about it on a MTB forum. so do a google search for it.

G

any chance of visual aids im stuck in hard place

any chance of visual aids im stuck in hard place

That is about as open-ended a question I've seen recently. Where are you stuck or maybe I should ask what are you stuck on? What type of visual aid are you looking for? Details...we need details.

I wrote a program that does what the original poster wants but it is not likely to work with AutoCAD LT, as it is a lisp routine. In the attached drawing you will see the outcome of the routine (2 wrap-templates). Since I am not allowed to make it public, send me an email, if you are interested.

Paul.

2pipes.dwg

Try http://www.thesheetmetalshop.com/ excellent for patterns and how to.

thanks lads i got it sorted ! it was a simple task just to make a development of 45 degree inter section for one of the fabircators and me being a self tought autocad user trying to impress wanted to get it right fast for them . thanks again lads great help as usaul

Good you got it sorted out ulticad man!

Not a greatly difficult task but, presentation speaks for itself!

Hello, I'm a new member of Autocad forum and I'm searching this pipe joining routine for so long. Could you send it to me, too?

Thank you very much!

I wrote a program that does what the original poster wants but it is not likely to work with AutoCAD LT, as it is a lisp routine. In the attached drawing you will see the outcome of the routine (2 wrap-templates). Since I am not allowed to make it public, send me an email, if you are interested.

Paul.

hello PaulMcz, I'm searching for that pipe joining routine for so long! Does it work with autocad 2009? If it's so, could you tell me how to obtain it? I'm a bike frame designer and I'm searching for a tool to give the dxf cut file to the lasertube machine.

Thank you very much!

Autodesk Inventor Frame Generator and Sheet Metal tools.

hello PaulMcz, I'm searching for that pipe joining routine for so long! Does it work with autocad 2009? If it's so, could you tell me how to obtain it? I'm a bike frame designer and I'm searching for a tool to give the dxf cut file to the lasertube machine.

 

Thank you very much!

The program I wrote draws a flat wrap-around template for marking the cut line on the pipes. I don't know what kind of "dxf cut file" your "lasertube machine" needs. See this thread:

http://www.cadtutor.net/forum/showthread.php?t=29251&page=2

Checked with 2010 - WORK

BTW: thank you! it is great tool for me

First of all thank you very much for the help. Not being so good with autocad I followed the thread instruction to open the list routine, and it works. But how to see the actual drawing? I mean the actual cut line? Excuse me for being so ignorant...

First of all thank you very much for the help. Not being so good with autocad I followed the thread instruction to open the list routine, and it works. But how to see the actual drawing? I mean the actual cut line? Excuse me for being so ignorant...

I have sent you a PM. Check it out.

would like to get your lisp routine for pipe intersections. Thanks:)

Hi, I would love to check out your program. I am trying to come up with a couple templates as part of my summer internship. Sadly, I cannot figure out how to e-mail you without your e-mail address...