how to draw eccentric reducer

[srinu_vasu38]

Thank u very much regarding reply to my thread. but i am unable to draw eccentric reducer using the enclosed sketch. Please help me sir.

eccentric reducer.dwg

[nukecad]

I cant see your drawing, dont have cad on this PC but I uploaded some blocks a while ago here- http://www.cadtutor.net/forum/showthread.php?t=38775&highlight=insert&page=3

 

I'm pretty sure that there are some eccentric reducers in the 'elbows-ts-flanges' zip.

 

What the reducer actually looks like depends on the manufacturer, some are a straight taper from one diameter to the other, some blend the two diameters with radii.

 

EDIT

Sorry those blocks are only 2D, I hadnt been able to open your drawing to see it was 3D you wanted.

[ReMark]

I would recommend using the LOFT command.

 

For example, to LOFT the OD of the eccentric reducer first pick the larger of the two pipe OD's then the smaller. AutoCAD will prompt:

 

Select cross sections in lofting order:

 

It will respond with each pick: 1 found and it will tell you the total selected: 2 total.

 

The next AutoCAD prompt will be:

 

Enter an option [Guides/Path/Cross sections only] :

 

Your response should be to type the letter G for Guides then press Enter.

 

AutoCAD will prompt you to Select the guide curves:

 

It will tell you how many are found and the total.

 

The "guide curves" in this case will be the combo straight/arc lines on the left and the one straight line on the right.

 

AutoCAD will then create a LOFT between the two circles using these guide lines as a kind of restraint.

 

Do this for the OD and the ID of the reducer. SUBTRACT the ID from the OD and you're done.

 

Addendum: I think you will have to offset/copy the OD guide curves a distance of 12 units to create guide curves for the ID.

[ReMark]

I had a little trouble working with your drawing so I had to redraw portions of it. I also created two new layers, one for the reducer OD and one for the reducer ID. I changed some line colors too for purposes of clarity.

 

I did one other thing too and that was to combine the arc segments and straight lines you had on the left (shown in red) using the Pedit command.

 

Here is the result of my efforts which proves it can be done. Now, it is your turn.

 

[JD Mather]

The complex guide curve you have on one side must be a joined polyline.

I then tried Shell but the part would not shell.

So as Remark indicated you will also need to offset the guide curves 12 towards the inside and do a second Loft and the Subtract.

 

You might want to do the tutorials in my signature or type Loft hit Enter and then hit F1.

 

 

Looks like ReMark gave you then step-by-step while I was typing.

[ReMark]

Dang! I always forget about the SHELL command. Don't know why. Thanks for the reminder JDM. I'll add it to the list.

[JD Mather]

Actually I should have said, "it would shell at a thickness of 6 but not 12, so like you did, I used two lofts and then subtract.

 

I also increased facetres to max 10.

And like you did, I created additional layers to help control the flow of the work, especially if editing will be needed.

[Lee Mac]

I remember trying to make that in one of my first LISP programs - but I only had '04 back then, with no LOFT command available...

 

http://www.cadtutor.net/forum/showthread.php?t=33919

 

It really needs a complete overhaul - I'm not particularly proud of the programming involved in it now..

[milsonpr]

please give the development sketch of the eccentric cone with making procedure

[JD Mather]

please give the development sketch of the eccentric cone with making procedure

 

attach the dwg file of what you have attempted so far.

 

see also

http://www.cadtutor.net/forum/showthread.php?81866-How-to-draw-this-into-3D