Custom work - Feedneck boss adapters Tech index > Custom Work > Feedneck boss adapters

These small rings are useful when upgrading older equipment to be used with any feedneck built to Empire's latching boss size, including my Unilock-style feednecks which are used on all bodies made by Nummech. The latching feedneck style has taken hold with many developers as of around 2010, which is the reason for my feednecks utilizing the body-boss latching system, but people still want to use the feednecks on other markers too. Using the modern feedneck on older markers is very doable, but requires making a custom adapter ring for virtually every marker thread style.

Empire started this trend by selling a Mini/Axe feedneck adapter with their own latching feedneck. While the Mini and Axe share the same feedneck threads as other markers (Shocker, Impulse, Ion, Bushmaster, Omen, etc), the Mini/Axe feedneck adapter will not fit on most of the other markers because their milling is higher than the Mini/Axe body. It was for this reason that I set out to make as many different adapters as would be necessary, regardless of the required heights.

To date we've made a LOT of adapters. To see the full list (along with their respective heights) check nummech's webstore.

Sizing and testing:
The development process for these adapters involves making some test items, then check their height when installed on a marker. For the purposes of this particular article I'll use the AKALMP adapter ring as an example. The AKALMP feedneck size is published, but the exact thread depth into the body is not known, so I needed to make a small variety of different-sized adapters then test the fit of each adapter as installed on a marker body. Each test adapter is 0.010" different in height, making five total adapters spaced out across a 0.050" window. If too tall, the feedneck will have wasted space; if too short, the feedneck won't be able to mount the adapter. Surely the ideal size will be somewhere within this range...
AKALMP adapter rings for testing
AKALMP adapter ring cut on CNC lathe

I sent the parts out for anodizing to ensure they would have the proper finish as used by other players. Once the parts were back from anodizing, I arranged them by their exact height (the numbers correspond to 0.xxx inch heights)
AKALMP adapter rings for testing

The next step is to install each adapter on the test marker body, one by one, until the correct height is determined. According to my measurement, the ideal size for this particular AKALMP thread size was 0.480 inches. It appears that a slightly shorter height could be used, but I prefer to leave about 0.010" of extra height on the adapter just in case any bodies have small deviation of thread depth.
AKALMP adapter installed on Viking
For the test Viking, the best fit adapter was between 0.475" and 0.485". Going forward I would simply split the difference and make an adapter with height of 0.480". The actual difference in height is extremely small (less than the thickness of two hairs) but it's a good theoretical target size that others can use if they wish to make their own lathe adapters.

Production:
With the correct size in mind, I would set the machine to make a batch of adapters then send those parts out for anodizing just like the prototypes.
Assorted adapter ring batch
I don't make huge batches of adapters because the demand for converting certain markers is fairly low. We usually make them in batches of 20-40 depending on the demand. Generally, making CNC component batches of that small size is not desireable because of the setup time being spread across a short quantity of parts, but in this case it's easy to make small batches because every adapter ring uses the exact same material, tooling, program setup, and most other details. The only difference is the actual CNC program used to cut the part, but even that is very similar from adapter to adapter. This program versatility lets us make even a small handful of adapters to resupply any that are getting low. We only keep maybe 20 on-hand at any time, but if any quantitiy drops down to around 10 then we'll make a batch to resupply every adapter that is getting low on stock.

Once the adapters are turned out from the lathe, Each one is inspected then set aside to be engraved. The inside engraving is used as an identifier to show which thread style belongs to the ring, and also the ring's height in three-digit numbers (again code for 0.xxx inch height). I use an electric scriber to create the marking. It's not ideal to draw on the inside surface, but I've become skilled at it over the years!
AKALMP adapter ring identifier

Here's a finished and anodized AKALMP adapter installed on a Viking project body:
AKALMP adapter with Unilock feedneck

Feedneck examples:
The finished adapter can be used with any Empire-spec feedneck, such as either of my Unilock styles, or any other compatible feedneck. Here's some examples with assorted markers:
Adapter ring with feedneck installed on Mini
Adapter ring with feedneck installed on Mini-GS
Adapter ring with feedneck installed on Nerve