Please see the attached file.
I created the outline of the parts then I made it into a group. They are mirror images of each other for Left and Right,
I then opened one group for editing and tried to use the Push/Pull funtion to extrude it 50mm.
The function does nothing.
It behaves as if there is no surface to pull out, but no message of any kind is displayed.
If I use the Plugins/Cleanup/Erase stray edges function, both my parts disappear.
As far as I can tell from visual inspection at high enlargement, there are no gaps in the outline, and all the edges lie in the same plane.
The problem is probably due to something I am doing wrong, but I have no idea what it is.
I exploded the group and tried again to Pull it out, with no change in behaviour.
The same applies to the 2nd group.
I am using SU2014 Make (not Pro) on a Windows 10 desktop with Intel i5 processor, 16GB DRAM and 2TB of hard disk, and one 21" display.
Any help will be greatly appreciated.
Plastic Feet.skp (71.6 KB)