Development lab: Unilock Feednecks

This page contains information on the design for our Unilock feedneck system. While this item may seem simple, it's actually one of the most complex parts of a paintball marker, due to its small size and high number of cuts made during its fabrication. The amount of design and revision time spent on this clamping feedneck is simply staggering; it took years to make, and its design actually pre-dates any of Nummech's other products (although the Unilock was not made available for public sale until 2014). This is one of our best upgrades due to its simplicity.

Unilock feedneck design:
Historically I have always been a fan of feednecks that use locking collars compared to feednecks that are one-piece flexing designs. The locking collar system generally allows the feedneck body to have a greater clamping range because each little slotted section only needs to flex by a small amount when tightening around a hopper. However, the "newer" one-piece design is favored in industry because it's typically more simple and easier to produce (therefore cheaper) but one-piece clamping feednecks seem to experience less effective clamping range. The clamping is spread across two big areas so sometimes care must be taken to avoid long term damage. I see online posts about this issue at least once per month; the one-piece design seems to work adequately but the "older" locking collar feednecks are clearly a tried-and-true system which doesn't run into the same issue.

Above: Comparison of clamping feedneck designs, both lock collar and one-piece styles.

Enter the Nummech Unilock feedneck! The reason we chose the name "unilock" was twofold; we built the feedneck to be compatible with any Empire or Eclipse feedneck boss mounting points, and additionally because the locking collar design has a huge clamping range which is compatible with virtually all types of loaders.

Above: Modern Unilock feedneck CAD design.

Unilock prototype:
The initial Unilock feedneck design was very minimalist compared to the production version that we make today. In fact, the original design was borrowed from a special marker project in 2011 which used an earlier feedneck that I designed all the way back in 2009! I updated the original plans to be compatible with Empire's feedneck boss dimensions, meant to be paired with a boss-style mounting point on top of the marker body. All our Nummech bodies have this mount built directly into the milling; players with other markers can also use any of our Empire-spec threaded adapters too. The choice to use Empire's feedneck spec was due to its prevalence, while being shorter in height compared to Eclipse's similar mount. Any quality Empire feedneck is compatible with Eclipse's boss, while the reverse usually isn't true.

Above: Prototype Unilock feedneck components.

The first Unilock feednecks were made in this "minimalist" shape. The design was sound, but it's a good example of a "first run" product which needed a little refinement before more could be made. I made lots of changes, including some of these:
- Added additional details and cuts around the outside, to make the feedneck appear more striking and aggressive.
- Modified the cam-action in such a way that it would lock in the "tightened" position, instead of popping open under force.
- Enlarged the lever and lockring to make them easier to operate, which also had the benefit of adding strength to both parts. The lockring underwent a total redesign. I altered it's shape such that the top surface would "wrap" around the inside of the feedneck housing itself, which would prevent damage to the housing's clamping ridges when inserting a hopper.
- The threaded roll nut cannot be the same material as the lever (because they will seize together) so I chose brass for the prototype because it's easy to machine. However, I wanted to upgrade the material to stainless steel because it's drastically stronger and won't tarnish over time, unlike brass. I also like the silver appearance of the stainless steel nut, although that's a minor benefit.
- Widened the body mount gap to allow an object to be inserted for easier installation/removal.

Production Unilock:
After nearly two years of testing, we finally set out to make the first batch of feednecks in 2014. Nummech's new Shocker and Axe bodies had become available, so it became important to offer a feedneck that could be bundled with the new marker body as a package (rather than buying Empire's basic feedneck).

Above: Revised feedneck housing during the production process.

It was at this point that many other players requested buying the feedneck as a stand-alone upgrade to replace their stock parts, so we quickly made a second batch and expanded the color choices to both dust and gloss, silver or black. Below is a picture of the finished feedneck on an SP Nerve marker:

Interested in machining? Check out this video which shows the feedneck milling process on one of our CNC 4-axis mills:

Above: Production milling for the feedneck housing component.

Each feedneck comes ready-to-be-installed with a plastic shim tool, which ships attached to every feedneck. The small shim allows you to safely open the feedneck's clamp just enough to precisely slide it onto the marker's mount. Afterward the shim is removed and the clamp can be tightened as normal. The plastic shim can be kept in your toolbox for future use. The quick-and-dirty way to do this is with a screwdriver or metal coin, but I love using a little piece of plastic since it pretty much eliminates scratching the marker body. We cut the plastic shims out of a large cast sheet stock on our laser router.

Above: Plastic installation shim in use.

The paintball market determined a pricetag for this product before it was ever released ($40 each). By its production time, I would like to sell the Unilock for more like $55 each, but it's difficult to convince people to spend that much money on a feedneck because the amount of time involved is difficult to understand. Unfortunately for us, the Unilock feedneck requires a lot of time to fabricate, compared to items of similar cost such as a trigger or drop forward, which can be produced in nearly half the time yet carry the same pricetag. It becomes obvious why most companies have eliminated the complex feedneck designs like the Unilock; the less complicated designs make it easier to justify the typical $40 pricetag that follows most feednecks. However, despite its high complexity, we refuse to simplify the design because it's the best no-compromise system available. It's the only way to get it out into players hands where it belongs!

Thumbscrew upgrade and No-rise versions:
Players reported great results using the Unilock in action after the first big batch in 2014. The lockring design fixed the clamping issue with several OEM feednecks on markers like Mini-GS, which was the intended benefit. However, we received two main requests for revisions. The first feature people wanted involves a tool-free clamping adjustment knob rather than using an allen key for adjustment. This was an easy feature to add just by fabricating a new thumbscrew which could slide right in the area normally occupied by a cap screw. Technically the new knob component added yet more time to the production cost, but the knob was such a good idea that we decided to start using it with all feednecks going forward with no added cost.

Raw thumbscrew knobs ready for finishing operations.

The second feature people requested was a shorter profile to accomodate "hacksaw modded" hoppers. The existing Unilock is already shorter in height compared to many stock/OEM parts, but some players were still looking for something even shorter. Solving this issue would require some creative work; my biggest problem was that our high-range clamping ability is based on the housing's height, so reducing height would probably restrict the clamping range too. The other problem is that a shorter feedneck requires a modification to the hopper, usually done with a hacksaw. Homebrew hopper modifications aren't difficult, but they do require additional work on part of the player, which complicates things for us trying to make "drop in" upgrades that don't require modifications at home.

Well, people still wanted the option for a shorter feedneck. I came up with a redesigned feedneck housing measuring slightly shorter while still maintaining compatibility with Nummech's existing lockring, lever, and thumbscrew. I called it the "No-rise" version just like the super short feednecks of yore. The stubby height is even shorter when used on an Eclipse marker.

Above: Unilock No-Rise CAD design and comparisons.

The Unilock No-Rise is very similar to the standard version, but uses a smaller clamping screw and has more intricate cuts around the outside because less space is available for milling. The new feedneck was prototyped then sent out for testing; results were still good, but the clamping range was definitely reduced. For this reason we decided to continue selling the original Unilock feedneck in addition to the new "No Rise" variation. If people ask which type is best, I always recommend the tried-and-true standard height Unilock because only a small subset of players are die-hard enough to hacksaw their hoppers. Most people just need reliability and clamping range, which is where the standard Unilock is best.

Above: Unilock No-Rise installed on various markers.

At present, this feedneck has been pushed to the point where I don't believe there's anything left out from the upgrade kit. Over the years we've refined the design and added more parts and more options, crammed into the same small assembly, while still keeping the cost identical to ensure the product is accessible to everybody. It's truly one of the most successful Nummech upgrades thanks to all the feedback and suggestions from players everywhere!

Written by Andy "Ydna" DuBuc
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