The alternate installation technique SPECIFICALLY for the Z-kit covered here:
Standard R-hop Installation:
Installation of an R-hop, particularly the Z-kit, is not particularly difficult but can be a little time consuming. I highly recommend new installers take their time, do not try to rush the process, and DO NOT ATTEMPT TO USE A ROTARY TOOL. A rotary tool (dremel) is an excellent way to remove material quickly, but often times can do so too quickly and/or launch your R-hop into low orbit. The instructions can seem a little confusing and long winded, but thats simply because there are so many ways to go about doing it.
Get a grip on your R-hop. If you are using one of the installation
aids this isn't too difficult. If you don't have an installation aid
a hint of cyanoacrylate, henceforth referred to as CA, on the back of
the R-hop or a drop of hot glue will secure it firmly to a surface
for easier manipulation. Careful manipulation is key to a quality install.
Adjust the length. This is best done with a VERY sharp blade and in a
single clean cut. Measure twice, cut once. While previous iterations of this manual suggested leaving a gap at the front of the R-hop, it is now recommended for optimal performance you aim for a snug fit in the window, and radius the trailing edge of the R-hop to prevent pinch-type jams. Mark
the R-hop carefully, and cut it against a hard surface.
key to a good install starts with an R-hop that fits flush with the
outside of the barrel. The R-hop itself is pliable so the best way to
achieve this flush fit is with adjustment of the so called “legs.”
Gentle application of sandpaper (finishing with 600 grit or higher) can then
be used to remove material from the legs or a very sharp high angle
If you go too far an easy trick is to build up the side of your barrel window either with pieces of paper CA glued together in situ, or for a more temporary solution pieces of a thin tape. Cut strips longer than necessary, square them at the ends, and make sure they sit shy of flush with the bore. Excess outside the bore can be trimmed off easily later. Using CA and paper is essentially creating a composite in situ, and can actually be easier than adjusting the legs shorter. Its not a hack at all, and is a very effective solution. This technique can also be used to rescue barrels which have been otherwise ruined by excessively deep windows.
Further improvement of the fit with the barrel on the outside can be
accomplished with a thin strip of sandpaper. Credit goes to Maekii
for this clever trick:
EngelMacher has used a shaving razor to accomplish the same thing. (again done to an R-hop on the barrel) People's response to this however has been mixed.
Adjust the channel. This is the part of the R-hop that contacts the bb. You would be amazed at how gentle a touch is required to spin a bb. Again credit goes to Maekii for coming up with the original version of the installation aid. I added a few touches and worked up a pre-made version people can easily acquire, but the original concept is his. Feel free to experiment, this is why the R-hop is kept open source.
Test. You're primarily testing channel adjustment here. With a
bucking (mound and alignment ridge removed) and hop unit installed use a small rod to gently press a bb
through the chamber. If the bb doesn't go through with just the
slightest push, or feels like its catching somewhere rather than
pushing through smoothly, you need to adjust the channel further. If you can't press your lips against it and blow the bb past the R-hop chances are you have too much. (credit KJerry) Once the bb does this, you can move to actually firing rounds through
the R-hop to test. If you have under-hop its no problem, just use a nice nub
like the M-nub or Firefly nub to apply soft deformable pressure to
the top of the R-hop, over-hop means a little more has to go from the channel.
Secure your R-hop. Using CA “permanently” bond your R-hop in place. Be careful not to allow CA to enter the barrel, apply around the outside edges only. You can also flip your bucking inside out, put a drop of CA on top of your R-hop, and then unroll your bucking onto the R-hop. To undo this gently reach inside your barrel with a plastic or wood instrument and press upward on the R-hop around the edges to break the glue bond. (you'll hear a soft cracking sound)
You're Finished. See wasn't that easy?
The Z-kit. Whats different, and whats the same?
The Z-kit is a series of different size IR-hops. It basically saves you step three, which is the hardest step, and in many cases step four as well. If you have a deeper barrel window, and/or want to shoot lower mass ammo, channel adjustment may be necessary. Tester feedback, and subsequent customer feedback, on the Z-kit has been immensely positive. It doesn't sound like much, but it really makes a world of difference.
I still occasionally get questions/complaints about low
accuracy/performance for "no apparent reason." The four
most common causes of this are:
The R-hop Q&A thread for users who require extra help:
If you still find yourself stymied, or just want to see other
people's complaints/issues/solutions, there are two old installation
manuals on public