I quite liked the look of this one from Ali-Ex. Underground MCM mechanical mod.
This is a stackable 21700/ 18560 mechanical mod, comes in various coloured coatings and the extension stacking piece is just a few dollars more so I bought the two as I saw potential in both pieces.
These are well made solid chunks of brass for the price and come with copper button derlin cell holders, silver plated ultem switch and a clip sealing plastic foam lined box.
I did order the plain brass version but it was out of stock so accepted the black coated instead.
Main unit with extension piece:
The painted coatings are not very durable and scratch fairly easily. I used acetone to soften it then wire wool to take most of the coating off from the outer shells leaving some black in the machined grooves.
So what can I do with these things?... :)
Main MCM Underground mechanical mod build:
CRX Underground MCM Triple Nichia 219C 5000K - Lxl TA Driver - 18650 - Piston Drive E-Tail Sw - 2430lm.Triple Nichia 219C 5000K emitters
LED4P Copper DTP MCPCB
Carclo 10508 optic
22mm x 1mm ARC glass
Hand made GITD dual colour glow gasket
Lexel 22mm E-switch driver
Anduril firmware
Copper pill
Copper lined body
Copper tail switch internals
Piston Drive electronic tritium tail switch
Max - 2430lm
Throw - 122m
Length - 90mm
Width - 28/ 31mm
Weight - 260g (With 18650 cell)
CRX Underground MCM Triple Nichia 219C runtimes:
This was a difficult build due to the size restriction of 90mm but I managed to make it a piston drive, the electronic switch is mounted on the driver board so the cell is the piston to operate it.
Copper lined throughout for mass and heat distribution.
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Part two, extension piece build:
Again I stripped off the black coating and cut off the protruding front thread to use as the screwed bezel for the piston drive light.
I took some build pictures with this part.
The lights are built pretty much the same way with copper tube throughout.
Pill:
22mm x 1mm copper tube pill housing, brass centre pill with driver retaining ring, 22mm x 1mm glass, 22mm brass bezel.
Convoy 8x7135 driver with brass button, Nichia 219C 4000K 90CRI emitter.
Body liner section:
22mm copper tube, felt lined with brass insert for o-ring placements.
This extra copper helps transfer the heat from the pill all the way down the body of the light and provides good fitment for the 18350 cell.
Tail switch unit:
I potted the reverse clicky tail switch into some 22mm copper tube and soldered to the brass 510 hybrid threaded piece so we can have a screwed tail cap.
This unit butts down onto the body section compressing the 22mm o-ring on the brass tube insert.
The brass 510 threaded piece has some nice shapes cut into it so I filled them with a thermochromic/ GITD powder mix.
At cold temperature the inserts look black but with some heat and applied light glows bright green.
In order to have something to grip when tightening the tailcap down I installed four brass pillars around the switch, filling the already present vent holes.
These are 2mm hollow brass tubes filled with aqua blue glow powder.
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Complete:
CRX Underground MCM Nichia 219C 90CRI - C-MK 3A - 18350 - Rv Clicky Tail Sw - 600lm.Nichia 219C 4000K 90CRI emitter
Copper DTP MCPCB
22mm x 13mm OP reflector
22mm x 1.5mm ARC glass
Hand made GITD glow gasket
Convoy 8x7135 3A driver
Biscotti firmware
Copper pill
Copper lined body
Copper tail switch housing
Thermochromic Black/ GITD tail
Reverse clicky tail switch
Max - 600lm
Throw - 128m
Length - 75mm
Width - 28/ 31mm
Weight - 232g (With18350 cell)
CRX Underground MCM Nichia 219C 90CRI runtimes:
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Other Mechanical vaping mods I have made into flashlights:
CRX RV Titan I Triple Nichia 219C – Anduril – 18650 – E-Tail Sw – 2200lm.
CRX RV HammerHand Nichia 219C 4000K - LD-A4 - 18500 - Halo Tail Sw - 740lm.
CRX RV Titan II LH351D 5000K - LD-A4 - 18500 - Halo Tail Sw - 1200lm.
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