I made an adjustable kettlebell a few months ago. It worked. But there were things I did not like:

1. Handles were too wide. Didn’t let me get maximum range on some exercises.
2. Setup time was not as quick as I would have liked.
3. Make the entire setup a little more compact.
4. Handle was a little slick.

So here is my second attempt. The main weight holder is unchanged. It’s a 50 mm stem with a hole on top and a plate at the bottom. The plate keeps weight in place. There’s also thread on top to keep a handle in place for rows and carries. 

The plates go on the stem. We then slide a handle on and secure it in place with a bolt. You can race ahead with your swings, deadlifts and squats. You can see me using 45 kgs here for a row, swing and deadlift. There is room to bump things up to 55 kgs. The entire setup is more compact than the earlier one. It’s also quicker to switch plates and handles. Range of motion is improved too. Between the knurled handle and the ease of handling, I love it. 

The only downside is you can’t use it for pressing movements. That’s a fight for another attachment or tool. As always, everything was machined, turned, milled and welded within 16 kms of our gym here in Madras.