I'd be glad to try but I don't know what he wants to subtract from what.
Well, I wrote a detailed description of this particular problem and suddenly had a Homer Simpson moment, "Wait a moment!"
The problem was all mine, I had been working round several warning messages that were a massive clue, Extrude and 3d subtract will not work properly in 2D It is not over but I reckon this awareness may help mitigate my ubiquitous mix of eclectic problems!!!
For the record, here is what I wrote about the problem, a is the large cylinder. The two extruded circles, a and b are test objects for the Boolean subtract operation.
b is to be removed from a
I have done this procedure enough times succesfully to recognise when it is NOT working.
Normaly, I would select a, (a circle turns red), and then b, (b turns red), then press enter. this used to be reliable
At present, Sometimes, nothing happens when I select a, OR, b turns red!!!
I Hate problems that are randomly repeated.
IT'S NOT over yet..
I still struggle a bit with workplane vs worldplane, but a problem that may be related in effect is relative position.
For a while I was using 4 extrusions that would latter be combined as 1 object, (maybe not relevant), I had extruded by eye, planning to give exact z dimension later, however when I then tried to change the z val it simply increased the z pos from 18,5 to 29.434809, without changing the z size.
Incidentally, the x axis "appears" to be the 0 point on the z ruler. The workplane is supposed to be on the worldplane
Earlier today I performed the same procedure on an identical copy of this object set and it functioned as normal!
I fear that I sometimes may try things that inadvertently make an unseen feature. Not much I can do to change that behaviour
Thanks anyway, I have moved further in the right direction.
Best wishes Jim B