Unless you were first exposed to kettlebells first hand, you probably found out about them on the internet.  The problem was whether dumbbells would suffice to try out the motions, and were
there any viable substitutes. And there was always the cost issue.

Unless you know a welder, that proposition almost immediately runs to pipe fittings, which are our first some homemade kettlebells............

pipe fittings:

rattles a bit unless
shimmed.

a bit wide, so it's tricky on swings,

don't bother with
cleans

Now, swap out a reducing elbow on one end for the T , and it's a bit narrower. However it's still  tough on swings and cleans are still tricky....

A giant wire bail...

hmm..

Now, the first "real" Kstack prototype .

(follow the link for it's story)

Not homemade, but...

 the original Calvert Milo Kettlebell.

Very hard to find these days.....