3d bend 1

[jones55]

Hi,
Can anyone explain a easy way to produce a 3D bend? I have been told the only way is to draw it in 3D, can it be done in 2D? Looking at a bend in 2D it would appear that the inside of the bend moves towards the centre line and the outside of the bend moves away from the centre line,is there a way of calculating this offset.

Thanks for any help given

 

[borgunit]

http://www.massey.ac.nz/~odiegel/downloads/powerpoint/143-360-sheetmetal.ppt

"Everybody is ignorant, only on different subjects." — Will Rogers

 

[jones55]

Sorry,
I forgot to say this is for pipe bends to show if a pig will go through the bend.

 

[borgunit]

Do a Google search

"Everybody is ignorant, only on different subjects." — Will Rogers

 

[ctopher]

borgunit,
A very helpful sheetmetal file. Thank you.

Chris
Systems Analyst, I.S.
SolidWorks/PDMWorks 05
AutoCAD 06
ctopher's home site (updated 06-21-05)
FAQ559-1100
FAQ559-716

 

[cfee]

Bogunit-
I agree. Good link to important sheet metal info. I just scanned it, but I didn't see any reference to the "rule-of-thumb" approach prefered by many designers and the shops they use. Thoughts?

JONES55-
Don't draw it (as such). Meaning- don't draw the parts and add them together. Draw a conituous P-Line in the shape of the pipe run, and extrude-path a cross section. I Create a region of the OD, a region of the ID on the starting plane "normal" to the start-end of the P-Line, and do a boolean subtract of the inner from the outer regions, first. This keeps me from having to extrude-path 2 shapes and subtracting. However this will result in an APPROXIMATION ONLY. Next step- take a plan view along the extruded path of the pipe, and lay in a continuous p-line at the 2 opposing quadrant-points all along the pipe(representing the "O-D" of the pipe run), and vary the mid-point of each "elbow" bend-curve (the inner and the outer) representing the bend deformation toward or away from the Center-Line. Its only a 2D pair of curves, but you are now prepared to represent the pigging issue. Be careful, though, as I've seen both the inner and the outer curves (in physical application)both compress inward toward the ideal C-L of the run. But as you model the pigging unit, place it along the C-L of the pipe-run, you'll be able to demonstrate the problem clearly, and you'll have the application modeled for further use.

Good Luck-
C.Fee

 

[jones55]

C.
This seams like a neat solution, I will give it a try.

Thanks for you time

 

[NotReal1]

It might be easier to download the bends / pipe fittings from a website. I.E. http\\:

http://www.herculedesign.com\