Sheet metal elbow pipe - how to cut it in half and unfold it?

[patrykstolinski]

Hello - first of all, I'm semi new to Inventor - it's an amazing program I'm using since I needed something with importable(?) parameters into BOM's opposed to Fusion 360. I love this program. That being said, there's still a lot I don't know how to do. Currently I'm trying to make a bent pipe (half of it) in sheet metal so I can unfold it and see what I need to cut before I press it. English is not my native language so here's some pictures of what I need to do:

The excess material after being pressed is what I don't need

That's exactly what I need for the bent-half-pipe to look after unfolding in sheet metal part

So it can wrap around the pipe like this

I apologize for lack of clarity, I really don't know how to explain this in english so I hope pictures help. Now usually the way I make pipes is I create an arc with specific radius and angle, then make a profile and use the sweep tool. I never used the sheet metal part, but I did find some tutorials on how to make cylinders using contour roll - that's exactly what I need, but I don't know how to make an axis that's 'bent' like the pipe I need. I have found a way to create the sheet metal elbow part with a 1mm slot between to not have a closed profile, but now I don't know how to cut it in half and unfold it. I've attached the file I've made. 

The desired values for the 'shell' around the pipe are 82mm in diameter on a 98mm radius.

Thank you for any input on the matter, good day!

[Sergio.D.Suárez]

Hi, have you tried using the unwrap command in Inventor 2020?
I have Inventor 2018, so I can't try to reach a flattening of the surface. You cannot achieve a flatPattern in the conventional way.

I hope this helps. regards

[JDMather]

As suggested by @Sergio.D.Suárez , try adjusting the parameters in Unwrap and see if you get a "close enough" result.

[philip1009]

To put it simply, Inventor sheet metal at this point can only provide accurate flat patterns of parts formed by brake press and straight roller, any forming that stretches the material in more than one direction at once typically cannot be flattened without problems getting in the way.  The unwrap method as Sergio and Mather suggested is your next option.

[patrykstolinski]

Thank you all for replying.

Unwrap created some weird results, using rigid frame on the lower arc it made everything too big:

Without the rigid edge it created something resembling what I need:

though as you can see there's way too much material on lower arc and a bit too little on the upper arc. Now I'm trying to get the 'flat pattern' to work, but when I create a flat pattern from something like this:

it makes literally a rectangle material:

I've attached a file of the sheet metal part I'm trying to use flat pattern on, maybe there's something I didn't tick? Or is it normal behaviour and I can't get it to 'flatten' the part?

[JDMather]

You will not get a correct flat pattern of that part.

[S_May]

[johnsonshiue]

Hi! The rectangular flat pattern is a representation of an unrolled elbow. The rolled (Contour Roll) shape created in Inventor Sheet Metal is meant for keeping the unfold length of linear extensions on both ends intact. The roll itself is not meant to be flattened.

Many thanks!