[PART 1] Official BLF GT Group Buy thread. Group buy officially closed! Lights shipping.

Original OP Archive*…as compiled and maintained by TheMiller until 5 Jan 2018. The history of the GT is here. Note that not all details are valid anymore.*

The First post in this thread will have the latest updates and “change log” moving forward. This post will have the specs of the production light and the next post will have the list of those on the GB list.

Official GT support thread with all your post-purchase questions and the manual

Optional Samsung 35E are $40.50 if purchased with the GT.

Team:
Tom E: Narsil development
Texas Ace: PCB design
MRsDNF: Communication
Thijsco: CAD analyst production / design
Fritz15: CAD analyst production / design
M4DM4X: sales
Neal: contact in China well connected in flashlight world.
5AR: Original CAD design inspiration
JasonWW: Thread and information management

User manual
BLF-GT user manual draft13.pdf
(The first production run shipped with revision 12 of the manual. The revision 13 changes are minor.)

Chinese translation by steel_1024:
BLF-GT Chinese user manual V1.2

Joe’s excellent cheat sheet for the GT
Cheat sheet

NarsilM firmware development thread
NarsilM thread

NarsilM 1.2 source code and ready-to-flash HEX files
NarsilM 1.2 files

Texas Ace’s review of the final prototype before production started. Your light should look pretty much like this:
Prototype 2 review

Narmattaru’s review of the production light.
Click here

VOB’s Prototype Review video

VOB’s un-boxing video of the production light

VOB’s Using and Programming of the light

Specifications

  • Emitter:
    12 V Cree XHP35 High Intensity, neutral white 4000k, mounted on copper 44.5mm DTP MCPCB
    Flux: >2000 lm
  • Intensity:
    >1 Mcd (ANSI throw >2000 m)
  • Firmware:
    Tom E’s open-source NarsilM v1.2
  • User interface:
    • By default the GT is set to use the very intuitive Narsil smooth RAMPING UI. Instant access to a 2.5 A TURBO mode is also provided.
    • A more conventional discrete level MODE-SET UI is available as an alternative. Any one of 12 pre-defined mode-sets can be selected.
    • MOMENTARY mode is useful for signaling purposes or rapidly/briefly lighting up targets.
  • Battery:
    Four or eight button-top 18650 cells (4S1P or 4S2P). Protected cells are recommended. Cells are not included.
  • Driver:
    35 W, 2.5 A regulated buck driver with conversion efficiency that exceeds 90%. Parasitic drain while OFF is ~150 μA (~250 μA with button back-light on).
  • Reflector:
    118 mm ID, aluminum, smooth finish
  • Lens:
    Glass with anti-reflective coating
  • Body:
    Aluminum with Type III hard-coat anodizing
  • Tripod socket:
    Standard 1/4 inch threaded (1/4-20 UNC)
  • Button:
    Tactile with back-lit rubber boot
  • Ingress rating:
    Equivalent to IP65, do not immerse in liquids
  • Weight:
    Approximately 1.8 kg without cells
  • Weights According to Hunter1
    BLF GT
    with batteries 2273 g (8 × 35E)
    tail-cap 91 g
    one battery holder 64 g (empty)
    one battery 48 g (35E)
    one battery holder 259 g (with 4 × 35E)
    two battery holder 518 g (with 8 × 35E)
    battery tube 285 g
    BLF GT head 1379 g (with screw 1381 g
  • Dimensions:
    135 mm Ø head x 310 mm length
    85mm fin OD at button
    56mm battery tube
    62mm battery cap OD

Got a reply from the NASA contractor that is using the GT for research today now that they have had some time to play with the GT, I will quote part of it it below

I would say that is an endorsement I can be proud of :smiley: