My wife just bought a lamp at Target, the kind you have to self assemble the rod from 4 hollow pipes and a base, where the electrical wire is already threaded through all of them. Each of the 4 sections screws into the one below it, and finally the bottom one screws into the base.
The rod sections / pipes screw into each other perfectly and tighten nicely.
The last one that tightens into the base is a bit too large, you can screw it on all the way but then the whole thing wobbles, if I try to tighten it anymore it keeps turning freely. After unscrewing it and re-screwing it back a few times I realized it is so big it literally can be pushed down instead of screwed in.
This thread has some interesting suggestions: What can I use as a thread "tightener" compound for a free-running bolt?
I tried plumbers threading tape and it got squeezed out and shredded and didn't really make a difference. I tried Scotch tape and had the same results. (I do think I may have put too much of both, I probably went around 7 or 8 times).
Finally I tried dental floss, which helped some - its a bit tighter now and I just left it as is.
Any other suggestions?
Since I saw this question on other threads: The base itself has an extruding nub with threads that the bottom section covers and screws over. Both of them have threads. Both of them are hollow and the electrical wire goes through it all.