Hi Guy, try with this version, I've simplified the edge structure here.

- Michael

Thank you Michael!

Can you give me a few quick hints on how you simplified the edge structure? I tried boolean union but it made no difference.

Hi Guy, I deleted this current kind of patchwork of multiple surfaces:



So it looked like this:



Then I used Merge on the bottom edges so that there was just one edge down there:



Then Construct > Extrude which will now make just one larger surface going across the whole side-wall area:



Then Edit > Trim the large side-wall surface with the top edges:





Then Edit > Join to glue the pieces together.

- Michael

Thank you for the workflow help!!

HI GuyLuke

我看了你的文件，并稍作尝试，将做的步骤用不同的线和名称作为注释 样式如图片并附加上制作文件，希望有所帮助（我不大懂英文，依靠机器翻译）
I have reviewed your file and made a slight attempt. I have used different lines and names as annotation styles for the steps, such as images, and attached the creation file. I hope it will be helpful (I don't understand English very well and rely on machine translation)






cam4.3dm为快速且模型为实体版本（图片soild.png）(Cam4.3dm is a fast and solid version of the model solid png))

It is also possible to separate face control points