Here’s how I set up my eccentric-nutted V-wheels. I haven’t had to make a single adjustment to them since I’ve done this (almost 2 months ago!)
Basically I spun the eccentric nut down to the head of the bolt, then used a Nylock nut on the other end. So it would go:
Bolt Head -> Eccentric Nut -> Carriage -> Spacer or Washer -> V-wheel -> Washer -> Nylock Nut.
The trick is to really crank down the nut against the bolt head. This locks the threads together and allows you to adjust it with an allen wrench.
This has a bunch of advantages, notably that you gain much more precision with the position of the eccentric nut rotation. You loosen the nylock with a wrench, rotate the cap head to the right position, then tighten the nylock. Just like adjusting valve clearance or tappets in a car. It also made it much easier to work inside the spindle carriage. Trying to get an allen wrench in there was quite frustrating. It’s much easier to get a regular wrench in there though I’d recommend using a ratcheting wrench.