Better way to model compound form

[lrochfort]

Hello all,

OS: Fedora 34 (Workstation Edition) (GNOME/gnome)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.Unknown
Build type: Unknown
Python version: 3.9.4
Qt version: 5.15.2
Coin version: 4.0.0a
OCC version: 7.5.0
Locale: English/United Kingdom (en_GB)


I`m trying to model a tiny flat CRT like you used to see in video doorbells, but I'm struggling with the glass section that flows from the base of the screen into the stem.

IMG_20210625_104115819_HDR-min.jpg (639.5 KiB) Viewed 233 times

IMG_20210625_104059022-min.jpg (811.9 KiB) Viewed 233 times

My first approach was to try some CSG by modelling each axis and combining pad and pocket operations, but I couldn't accurately model how the stem goes from a rectangular to circular section.

My second approach was to create multiple profiles on the XZ plane and then loft along them, but the result isn't accurate becuse I was effectively eye-balling it. I think it would be better to create layout lines in the XY and YZ plane and then sketch to those on the XZ plane, but I don't know how to do that.

A secondary issue I found with lofting was that it was inclined to flow outwards unless I selected the "ruled" option.

crt_stem.jpg (96.99 KiB) Viewed 233 times

The second approach is in the attached file.

I'd really appreciate suggestions as to how to model this accurately and effectively.

[openBrain]

Maybe using an addon such as Curves GordonSurface