This is an adapter to mate the military style upper lighting assembly and 2xAA battery pack from a fake cosplay Altimaster MA2-30 HALO and night jumper rated altimeter replica to a real unlit civilian Altimaster II civilian skydiving altimeter while retaining the real Altimaster fully intact. I got the inexpensive but very tough fake Altimaster when I realized it was cheaper to buy a whole fake MA2-30 cosplay altimeter just to replace the lost wrist strap and mounting rails than to buy the real Altimaster parts from my rigger or other parachute shops online. As long as I have the lighting parts in my parts bin I though I might as well see if they work together. Without the adapter the fit is not good leaving big gaps and requiring removal of the protective lens from the real Altimaster. If I get brave I might use one of the alternate color and a face decals provided with the cosplay altimeter with 0-12k ft and then 13-24k ft on an inner scale for the second revolution of the needle though the Altimaster II's accuracy is only certified to 18,000 ft.
A MA2-30 is the military version of the Altimaster II, it has an optional different gearing ratio to change the scale from 0-12 to a single sweep of 0-30 thousand feet, several different face markings and colors, and the battery pack and lighting module installed, and a much higher plastic lens to match the built up area containing the red low intensity illumination LEDs.
The Altimaster II civilian version sells for about US$180 new with a good pool of used altimeters for sale made over the 30-40 year production of the design; while the MA2-30 (NSN 6685-01-213-9035) is the same thing with the lights and optional different scale for about US$1000, government hammers and all, and if found used sells at a premium as a genuine special operations team collectors item. The cosplay altimeter was US$15 with free shipping, while the best deal for rails and strap was nearly US$30! A better deal if you want genuine jumpworthy Altimaster parts on your civilian Altimaster II is to get the ultra-reliable chemical lightstick lighting adapter, it was US$22.50 when I did my search. This adapter project is a bit of whimsy to play on the ground with otherwise wasted parts, and I wouldn't consider jumping with it though I have coveted a real MA2-30 for many years and would of course jump with that.
Warnings and Use License Conditions:
I have not printed this yet so can't promise fit and I am concerned about visibility even if the fit is great so on one hand equum dono accipitis ne dentes inspicerent but absolutely ask your master rigger what they think of jumping with this Frankenstein gadget on your wrist or chest because they can certify experimental things as airworthy, I DO NOT CERTIFY THIS FOR JUMPING NOR AM I A RIGGER WHO CAN LEGALLY MAKE SUCH AN ASSESSMENT!! I only license my design for use in the air if certified by an FAA or equivalent legally competent Master Rigger maybe an A&P for experimental aircraft designs, consult a lawyer competent in the field; it is your build then not mine, I provided a 3D model and idea only.
I only provide a general user license for doing a cool cosmetic hack for airsoft gamers, cosplay, or other for-fun no-risk applications including of course use of the model in the non-real digital realm, not for any application where any lives might be at risk when using this as part of free fall, other aviation, or any dangerous or life saving application without appropriate certification from a certified legally competent authority empowered to certify a modified experimental altimeter for your application. This is your own experimental modification using this adapter design and use license is not provided without first obtaining written certification from one of the above authorities.