Connecting 2 objects to create one group

Craftman Stave Column.skp (237.6 KB)
I am trying to create 1 complete side of a tapered column that has interlocking edges.
The example to the left would be it’s finished look. I copied one side then created the male and female edges and put the geometry into my top finished size of 6" and then again in my bottom finished size of 16".
I centered and separated the top from the bottom by 60". I then tried to connect the top geometry to the bottom but it didn’t give me a closed object.
Also when I rotate and copy one side the bottom “locks” together perfectly but the top a fudge off.
Did I approach this incorrectly?
Suggestions?

Craftman Stave Column-v2-(SU2017).skp (161.8 KB)
change the units back to what you had (I changed in cm when I made the model)

Thank you sir. I tried to connect the top and bottom by drawing lines connecting like points but I failed. How did you do it?

You’re welcome!

That’s because ‘top’ and ‘bottom’ were two separate groups. Explode both groups and draw lines over the one of them.

tps-05

Rookie mistake. Thank you again for your help and explanation!