Modified 5 Position Night Vision Aperture Modification Device by GhostJB

Last crawled date: 2 years, 11 months ago

Disclaimer
This is a modification to the Night Vision Aperture Modification Device (https://www.thingiverse.com/thing:4711559) that was created by Cloud9Actual, and is being posted with their permission.
TL;DR
This modification adds a 1.5mm "pin-hole" aperture to the aperture ring and modifies the caps to fit size 07 Objective and 23 Objective Butler Creek Flip-Open Scope Covers.
Intent
The intent of this modification was to solve two distinct issues which I had with his initial design:
The aperture ring lacked a "pin-hole" setting, or an aperture comparable to the one provided on the standard issue objective lens protective cover of PVS-14s.
The cap did not fit either of my devices as provided--an Elbit PVS-14 monocle and a Russian surplus PNV-57-E drivers night vision goggle set.
Execution
To address these issues, I learned how to use Blender.
The modified aperture ring (file name: ApertureRing-5pos.stl) has 5 indexed positions which correspond to the original three aperture settings (9.525mm, 5.56mm, 3.95mm), the added pin-hole aperture (1.6mm), and a blank section to block all light. All 5 positions are located such that they will not interfere with each other or provide excess light leakage.
Cloud9Actual's original design calls for a size 09A Butler Creek Flip-Open Scope Cover, but I found this to not be compatible with my own devices. Using digital calipers, I determined that my PVS-14s would accept a size 07 Objective cover, and that my PNV-57-E would accept a size 23 Objective cover. Using Blender, I resized the mating ridge and cap body to work with these size flip covers (file names, respectively: Cap-07.stl , Cap-23-L.stl).
I also created a "flipped" version of the 23 Objective cap (file name: Cap-23-R.stl), to allow for simultaneous deactivation of both caps with a single pass of my thumb between the two tubes, and to facilitate easier access to the aperture wheels.
Moving Forward
Cloud9Actual's design is brilliant, but as with anything, there is always room for improvement. Currently, the weakest point in the design is the connection between the cap and the wheel. In my limited testing with the smaller (07) cap, I have found the flip-open action to be very violent, knocking the aperture wheel out of its track and letting the detent slip out under it, jamming up the whole system. Potential fixes might include:
a "print-in-place" design for the cap which includes a solid and captive axis pin,
replacing the M2 screw with a very small rivet (strong, but not desirable due to tooling requirements and permanence of installation),
or incorporating a nut into the design and fixing the screw so as to be a non-rotating axis point.