it's much easier if you start to model this part using sheet metal feature and flat pattern
To flattern your part, you need to covert it to sheet metal and much more work will be done before you get the result
Teodora,,, I probably could have done this in sheet metal using a swept flange but that is not available in 2011 so I used "surface flatten". First I made a "mid-surface" surface in order to put the new surface midway thru your part. This would give me a k-factor of .5 if it was sheet metal. Could change that but I don't know what your material is and figured it would be close enough. I have attached a step file for you.
The file you posted was done in SolidWorks 2011. I can only do a swept flange (with cuts) in 2016 & 2017. You would not be able to open them with 2011. Do you have 16 or 17 available to you?
Yes i have
Here is a 2016 file using the swept flange feature. I also used a k-factor of .5 and the flat pattern is equal to what I had posted with the surface-flatten feature. I only did one side of this but you will get the idea and use the same method for the other side or build it from scratch. I built this on top of your original file and you can hide or unhide your body. I you use the sheet metal "Flatten" on this it flattens and automatically hide the original body.
Thank you
I was afraid this would happen with the "Swept Flange".. If you have "Surface-Flatten" available to you the results would be correct as in my first post (step file). If you do have 2016 or 2017 premium you can do that. Just look at the help file.
Notice what happens with the swept flange.
The flat pattern using the swept flange is not reliable in this case.
Teodora,,, I just notice that the corner fillets did not translate to the flat pattern. You may have to add them in the flat also or cut them some other way. This will require some thought and I just don't have the time this morning.
Hello,
To do this you just have to make a sketch with the open diameter and a new sketch on a plane at the start of the open diameter and use the function tolee folded swept then make removal of material to arrive at your finished part.
Teodora,,, I probably could have done this in sheet metal using a swept flange but that is not available in 2011 so I used "surface flatten". First I made a "mid-surface" surface in order to put the new surface midway thru your part. This would give me a k-factor of .5 if it was sheet metal. Could change that but I don't know what your material is and figured it would be close enough. I have attached a step file for you.