As you all know the new Revo and T-Maxx with 17mm hex do get some wobble on the wheels after some time.
English isn't my native language so I'm not sure it's called wobble. Please correct me if I'm wrong.
I had the same wobble and it got to me. First I didn't care but after a while it got worse.
I started to think about a solution and came up with this.
The text under every picture explains more (click image for high res).

This is what you start with. All stock axle and hex.
You can even see the marks inside the hex from the threads from the axle.
They are NOT supposed to be there and makes the wobble worse.

And this is how it looks on the car before modding it.
There is a little play between the axle and the hex making the wheel wobble.

This is what I have made.
It's a piece of pipe (metal) that I have threaded inside
and the grinded down to 6 mm outer diameter.

These are the different pieces I have used.
All stock parts except the pipe with threads.

Another angle of the same pieces
Here you see that I have drilled the hex with a 6 mm drill
so it will fit over the new larger end on the axle.
It is VERY important to drill the hole FIRST and then grind the pipe
Try it on and grind more if it doesn't fit.

Either use a large plier or some loctite to make the pipe stay on the axle.
You wouldn't want to lose it in a pile of sand somewhere.

This is the final product and how it looks.
The point is to make you sweat when you put the hexes on.
Twist and push and use some lubrication.
The harder it is to get it on the better the fit is.

I hope this can inspire some of you to do the same. It really works beyond what i imagined.
There is absolutely no play between the axle and the hex anymore.