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# Sheet metal problem

#### Rajeev

##### New member
I am not as savvy with sheet meta as i am with part modeling, so pls assist me to slove this problem.

I have a sheet metal part which is a blend of an ellipse and a circle with a hight of 75mm, I have to create a development drw of this, I cannot get it.

Ellipse =Rx 100 mm; Ry 60 mm

Circle = Dia 90

Thickness = 2 mm

Rajeev,

Too little information to assist. Picture might help.

Rajeev,

Try this. Model the part just like a solid. You can either create a thin walled protrusion, or cut out the inside. Either way, you should get the same result. Then after that, you will need to split the part to get your seam. I believe that this option is available in the Sheetmetal module (it has been a while since I have done Sheetmetal!). After that, Pro/E should be able to unbend the part for you, allowing you to create the fabrication drawing. Good luck!

Christopher

Rajeev,

It sounds like you're describing the creation of what the Pro/Sheetmetal training books call non-ruled geometry. Non-ruled geometry would be any surface that is bent or formed in more than one direction. In other words it is non-ruled if you can not put your ruler on the surface of the part and have the ruler touch the surface in more than just a point. Cylinders and cones are examples of ruled geometry, but a sphere would be non-ruled. My point is that flattening 'non-ruled' geometry in Pro/e can be very difficult, but send a picture of what you're trying to create and maybe I can help you better.

Rajeev, If you have a compound bend you will have to do a cross section unbend. The developed length is not accurate with a cross section unbend.

JP

is it possible for you to send me the part ?

karavasilis

Model it as a surface and try the Feature>Create>Tweak>Flatten Quilt. I have had some success with this when nothing else worked. The results are sometimes innacurate, but close. PTC also has a good example of what you are asking for online. I don't have the URL.

What Rajeev is describing is not a non-ruled surface. It's a standard transition duct from eliptical to round. A ruler will contact the entire length from any point on the circular end to a point on the elipse. Can't help you with the development as I haven't had to do that since I was working at a drafting table. BTW, it's not that tough to do with velum and a pencil. I agree that starting as a solid using a sweep is the way I'd start out.

If your manufacturing this as an FRP layup then cut the eliptical end to it's finished dimension. If you're trying to roll form sheetmetal I'd still make the starting blank long. Roll and temporarilly fasten the duct. Mark the finished size and then unroll and cut.

-Bernie-

I am having some problem in uploading the file, The question is simple.I have ae ellipse and a circle at the same centre, the height is 75mm and the dimension of the ellipse is Rx=10mm; Ry=60mm and the circle is 90 dia. it has the thickness of 2 mm.