Adding an indent to the face of a lofted flange in sheet metal

[Anonymous]

Hello. I am a relative beginner with Inventor, but I have a grasp of the basic concepts. I cannot for the life of me replicate the following design chute below in sheet metal mode (or parts mode for that matter):

Ive been using a loft flange to create the chute connection from the bottom plate to the top plate without the indent, and that works, but when I try to add the angled indent I get all kinds of errors. The difficult part is the indent on each side reaches a max depth at the middle flange, then tapers off back to flat at each end plate. In addition the end plates are offset from one another creating even more angles. I haven't been able to find anything regarding this online. Should I be building this face by face instead? Does anybody have any ideas how to tackle this within the sheet metal mode of Inventor?

For the record I'm trying to copy this design as one of our engineers who knows inventor quit and deleted all the parts files he was working with, so all I have is the PDF drawing. 

Using Inventor 2019

[johnsonshiue]

Hi! Please share your attempted ipt file here. There should be a workflow yielding the desirable shape. Forum experts can help take a look.

Many thanks!

[Anonymous]

I've attached the file. Basically I made three planes. One for each end of the chute, then one in the middle with a sketch of the indented sides with the idea being I would create a lofted flange from the middle sketch to the bottom sketch, then another lofted flange from the middle sketch to the top sketch, but whenever I try the lofted flange either way it fails. I've attached a printscreen of the error. Thanks

[Anonymous]

I've attached the file. Basically I made three planes. One for each end of the chute, then one in the middle with a sketch of the indented sides with the idea being I would create a lofted flange from the middle sketch to the bottom sketch, then another lofted flange from the middle sketch to the top sketch, but whenever I try the lofted flange either way it fails. I've attached a printscreen of the error. Thanks

[johnsonshiue]

Hi! I have seen this kind of behavior before. Aside from the sketching issue, the main problem in modeling this kind of sheet metal part is the sharp corner. Usually, the sharp corner is only shared by two sheet metal faces. In your case the sharp corner is shared by three faces. One of them is like a needle. There is no way you can create bends in such area. You will have to modify the design in order to add bends. The original design is purely based on sheet bodies without thickness. Inventor sheet metal is true 3D solid modeling and unfolding. It is processing the part as 3D solids, not sheets.

Many thanks!

[JDMather]

This is a quite interesting problem.

Is that bent from one sheet (if so, where is the rip) or is it formed from several sheets (if so, how many)?

[johnsonshiue]

Hi Mike,

One thing you could try is to set the Sheet Metal Thickness very thin (0.001mm). This can help mitigate the 3D solid intersecting issue. If it does not work in very thin body, it will not work in thicker body. For this particular part, you will need two separate solid bodies. If you create only one solid body for the design, you will not be able to make flat pattern of it.

Many thanks!

[Anonymous]

thanks everybody for the responses. I will try again and update if I have success!