If working in PD wb use a helix tool.





For attachment see, Basic Attachment Tutorial

I've tried but it never works.......

Here's another way....

Don't join sketches.


Do this in the solid.

FC is a solid modeller, stop messing around with sketches, keep them simple and add/subtract from solids.....

https://wiki.freecad.org/PartDesign_PolarPattern

I think this is a bug, it should be possible according to the wiki.

https://wiki.freecad.org/PartDesign_Mul ... formations

Don't reverse the pocket. Or use the fillet tool.

"TEE" junctions are not allowed for PD sketches.

Trim the lines next to the circles.....

Part joint connect.