The base is where my finger is, so the layer lines go up from there

Ok I’ve managed a male and female thread on a 150mm diameter, with a 0.3 offset, . It’s very tight can wind it on for 2 threads , and that’s it. Tomorrow doing another female with an extra 0.3 clearance on all faces, so see how that goes. I think it’s the shrinkage on the printer that’s causing the problem
Thanks Guys for all your help

I’m the problem, ha ha
I need a back to basics tutorial, I always seem to miss a certain point and nothing happens . I can see the way both of you do the threads but I’m missing something

Aha I got you mixed up, that was the one I watched

@Dave-R where is it?

ok , after watching Rich's video about 8 times I'm making progress. I was missing the upright extension
what's curve origin? I set it to -1.5 as in the video, so that made the male thread , now to make the female which ill offset by 0.3

with a 150mm diameter

I’m the problem, ha ha
I need a back to basics tutorial, I always seem to miss a certain point and nothing happens . I can see the way both of you do the threads but I’m missing something

with a 150mm diameter

here is the profile and my measurements, there are only 4 crests on the thread

hope this helps