Brass barrel clamp nut to replace part #9. Firmly connects the inner barrel to the hop unit, keeps the barrel centred and aligned in the hop unit.
Compatible with standard KC-02 hop units and Genesis hop units. The hop unit is not included!
We consider this part to be an essential upgrade to all KC-02's from now on.
Installation video guide here.
And another tip here if it's twisting during assembly.
Do not over-tighten the clamp nut.
The clamp works mostly on friction, it does not need to bite into the metal. Our testing showed a torque of about 7nm is more than sufficient, this is barely more than finger-tight with a small spanner.
The KC-02 has always had a problem with the hop rubber and inner barrel being able to twist slightly inside the hop unit because the barrel nut only holds the hop rubber into the hop unit and doesn't actually grip the inner barrel itself, which is true of both the standard and Genesis hop units. This isn't normally a problem if you're very careful to keep your barrel aligned when installing it into the outer barrel and attaching it to the receiver.
We figured out a while ago that if we wanted to incorporate a barrel clamp into the Genesis hop unit design, we would probably have to dramatically change the design if we still wanted to re-use the existing barrel nut and add in some little grub screws or something to grip the inner barrel.
But then, one day, a hydro-mancer named Project came up with the idea to use a compression fitting like an olive nut which is common in plumbing applications to add a simple barrel clamp to the barrel nut itself! Such a beautifully simple idea that could be added to both the Genesis hop unit and the standard hop unit!
So the ProjNut was born! We designed it and had it made in brass, as is fitting of its origins. You simply install the ProjNut as you would do with the normal barrel nut, align your inner barrel and hop rubber, and then you get to carefully tighten up the tapered nut to clamp your inner barrel to the hop unit so that it is perfectly aligned and centred, held firmly by the clamp.
Obviously, don't over-tighten it or you will crush your inner barrel. Just do it until you can't move your inner barrel anymore. Don't be an idiot and swing on it with a 2ft breaker bar. Probably only about 4 turns required, look at the pictures. The nut size of both is 15mm, so you'll need 2 spanners or adjustable spanners to tighten the clamp without spinning the main nut.