Ha, now it works perfectly :-) and your explanations make sense to me. Thanks a lot.

>Tomorrow I'll try to take a look and see what's involved in making "loose" (meaning not actually a part of the geometry database) objects work as input into async factories, maybe I can also get that tuned up to work.

That would mean that, when the script makes a thread for example, the profile and helix created using just .calculate()) will never appear? Also the cutter object and the cylinder would just be .calculated() in the background and just the finished thread pops up after some time like magic?