KWA Kriss Vector Light Unit
Whilst I was picking up the G&G LR-300 from Redwolf UK, I also bought a KWA Kriss Vector, as I'd fancied using a Gas-powered primary or (a more capable) secondary in skirmishes - and the Vector is quite unusual and unconventional in design. It's one of those 'so ugly it's beautiful' things I think - an eye catcher whether you love of loath it.
The KWA replica is a fantastic piece of kit, accurately replicating the 'Super V System' articulated bolt that reduces perceived recoil from the powerful .45 ACP round the real Vector is chambered for. Of course in an Airsoft weapon this isn't needed, but makes it a highly unusual piece, offering a satisfying feel when shooting (in addition to single, double and fully-automatic fire modes). KWA and Kriss have since seemingly parted ways, meaning that they don't appear to be making the airsoft Vector any more - potentially making it a rare item in the future.
As you'd expect, I couldn't leave the Vector alone and started bolting on the customary 'tacticool' items that were available. As it happens there are very few accessories for the Vector, as third parties don't seem to be interested in manufacturing accessories for a low-volume item like this. There are a few supressor attachments, including one with a barrel extension that ups the FPS considerably for longer-range engagements, and the usual 20mm sight systems and grips (although a special grip is included with the Vector).
But one of the interesting features of the Vector is a special cavity in the front (above the barrel) designed specifically for light/laser modules. From the factory it is fitted with a plastic 'blank' with the Vector logo on the front - but you can buy (real) tactical lights to fit the gap. As my local site has a few indoor 'bunker' areas, I needed to have a light fitted, so I had a look around. Unfortunately the only light kits I could find in the UK were either very expensive or out of stock. However as the kits were essentially normal tactical torches coupled with a plastic insert, I decided to design and 3D print my own insert, allowing the use of any torch of a suitable diameter.
Designing & Printing
After carefully measuring the factory-supplied 'blank', I modeled it into Sketchup as accurately as possible. I could then design my own inserts to accommodate any laser or torch that was sufficiently small in diameter. I've made the Sketchup model available in the (admittedly unlikely) case that you happen to have a Kriss Vector, access to a 3D printer and the desire to do the same.
For the torch, I decided to use a fairly simple 2xAA 'tactical' tailcap-switched light purchased from Tesco (of all places) for £10. It happened to be a fairly good quality copy of the more costly Fenix E21 I already had (which is itself probably a clone of something else). I'd spotted it whilst grocery shopping. I didn't want to potentially ruin the more expensive Fenix, so this made a great substitue. Given the identical size, it would also allow me to use the two torches interchangably. In hindsight, I should have bought more than one of the 'Tesco Specials', as they seem to be great value for quality CREE torches.
Of course a tailcap switch is of no use if the end of the torch is not accessible, so I designed the insert in two parts, the rear of which would replace the tailcap and allow me to run a lead out the back to a pressure switch on the side of the Vector. I used two cut-down springs as contacts for the batteries and the body of the torch, completing the cicuit with a pre-made pressure switch I'd salvaged from another tactical light. Such switches are also easy to make with some cheap microswitches and heatshrink tubing. I added a JST connection to fit through the opening in the side of the vector, making the whole module easily removable.
Assembly & Fitting
Unfortunately my Solidoodle 2 3D printer isn't 100% reliable and although the majority of prints come out very well, about 1 in 4 prints hang at random points. I haven't yet worked out if this is a software or hardware issue, and it seems to be entirely random.
My first attempt at printing the insert failed because of this, but it did print enough for me to test the fit of the insert inside the rifle's cavity. In the picture you can see the honeycomb structure inside the half-finished print. Also shown is my printed prototype Contour Roam camera mount, which I'll document in another article.
Unusually, the fit was perfect first time - so I immediately ran another with the same GCODE and it came out great. Only a small amount of post-print finishing was required as most of the insert would be inside the Vector, and therefore not visible. After a few coats of Krylon 'Camouflage Ultra-Flat Black' spray, the finish was very close to that of the Vector itself. The fit of the torch inside the insert (and the insert inside the cavity) was tight enough to keep both items in place, but the Vector has two screw holes in the RIS rail for the purposes of securing the official light kit (not to mention keeping the rail itself attached), so these provided extra security after drilling a couple of holes into the printed insert.
The fitted light looks and functions great, and the fact that it protrudes a few inches means that the supressor below obstructs little of the light cone it creates. Unlike the Fenix, the Tesco torch allows either end to be unscrewed to replace the common AA batteries, so this can be done in a few seconds without removing the torch from the Vector at all.