Need help with pipe project at work. Much appreciated ;)

Ive attached a drawing im working on at work. The boss wants a circular pipe at either end as shown, transversing into a rectangular sort of pipe along the centre section. The reason for this is headroom for lare vehicles passing under. Ive gotton part way, but im stuck as to how to merge the two together. Can someone please help me? much appreciated-davepipe.dwg

You can try making the transition piece with the Loft command.

how do i do that? sorry, im used to working with structural steel package, not entirely up to speed with AutoCAD 3D modelling

This is basically what it would look like. I didn't bother to Shell it out in this view.

It is what you were looking for is it not?

yes, exactlly. any way you can give me a step by step?sorry to be a pain, just want to learn!

yes, exactlly. any way you can give me a step by step?sorry to be a pain, just want to learn!

I'll certainly try. Let's start with this image showing your basic geometry (red), centerlines (black) and guide lines (blue).

The Loft command is responsible for the end result shown in the first image I posted. The following was copied directly from the AutoCAD Text window (F2). My comments are in italics.

Command: loft

Select cross sections in lofting order: 1 found (selected the circle)

Select cross sections in lofting order: 1 found, 2 total (selected the oblong shape)

Select cross sections in lofting order:

Enter an option [Guides/Path/Cross sections only] : G ("G" is for the Guides option)

Select guide curves:1 found (selected the horizontal blue line on left)

Select guide curves:1 found, 2 total (selected the horizontal blue line on the right)

AutoCAD then creates the solid transition piece.

Is that pretty much clear to you?

perfect, i will post my result up and show in 5 mins!thanks alot

Can't wait to see it. You're welcomed.

thanks so much for your help...heres the finished item. just got to add some flanges:)pipe.dwg

Did you want to keep it as three sections for a reason or are you going to Union them?

Just curious, what material and is that able to make it practically ?

If for headroom reason, should that rectangle be raised to top align with the circular pipe ?

I am just guessing would a transition from circle to square, then square to rectangle more practical...

ehm, i unioned the end pieces to the middle pipe, and added 2 flanges, as it will need to be done in sections.

And i did put that idea across to raise the rectangular part up, but the customer wants it like the way shown.

Very much appreciated, all your help. Thanks again - dave

ok, so iv produce the drawing of the pipe, which i will try and compress, and upload. Now, is there any way of unwrapping it into a development, so that it can be made by our shop? Thanks-dave

This will be my recommendation specially if you use piping and development alots:

http://www.litio3d.com.ar

Fantastic software. Very good link. Thanks so much

Why have you kept all the pieces separate?

Ive kept all of them seperate because when it is manufactured in our shop, it will be made in pieces and welded together. circular ends x2. Then conical shaped bit, from circle to oblong will be made in 4 seams and wlelded together, and the middle three parts will be maded with there flanges. All in all, it will come out in 3 bits, and then bolted together on site.

The reson the design shown has been used, and the oblong pipe is not at the top, is because the tunnel roof has extruding pices in it.

Gotcha. Thanks for the explanation. For fabrication pruposes separate is probably better. For finished drawing purposes (the entire shop/floor plan) I'd union them.

ah, ok, i guess that would be better in a large drawing. How do you split them again?or can you not?that softwrae link that mdbdesign left worked a treat on the "kneck" development. Thoroughly recommend to anyone doing pipework.