Another SRK-based lantern mod

9 posts / 0 new
Last post
macgyver88's picture
Last seen: 5 months 2 days ago
Joined: 10/27/2019 - 10:19
Posts: 4
Location: Germany, S-H
Another SRK-based lantern mod


After a long time of reading and learning through the forum, purchasing and modding some 18650 Tube lights like multiple convoy s2+ and BLF A6, i got in the need for a few nice camping lanterns.


At first i have to say, im really impressed how much knowledge is in this forum, and how much work alot of people invest, especially in the BLF project lights and custom firmwares.


After alot of reading about the BLF LT1 (and ordering one, can't await the arrival)

i came across DBSAR's very interesting V1 prototype, and alot of interesting informations in the design process.


so i got me a cheap SRK 12t6 clone host on ebay, and began to plan my build.


First, the host had a little meeting with my lathe:

 i pressed in a solid 6mm thick aluminum Shelf, added wire holes and a central m5 threaded hole, and fabricated a nice massive lamp head from aluminum stock.


Test fit: (the rubber hose around the screw gets replaced by a 7.5mm dia. aluminum tube with a white 3d printed sleeve , which hold the wires later)


I had a few very cheap XP-E HEW 2900k emitters on 16mm aluminum stars from FT, left over from a interior light project on my van.

i liked the tint and the cri looked not bad, but they produced wild tint shift when used without a big diffuser.

so i installed three of them in my lamp head with a bit of fujik, wired in parallel




The diffuser/shade was made by 3d printing, white translucent pla with 0.5mm wall thickness, which gave a good result for light output and illumination pattern.


The Stock 2Mode+Strobe FET driver pcb was gutted, i fitted 5 7135's on it,which gave me 1.75amp max. (around 580mA per emitter)

and epoxied a soic-to-dip8 pcb with attiny13a and voltage divider for battery monitoring on it,

flashed with a modified version of DTH_momentary FW from toykeepers firmware repo (edited for 7 modes + moon, and high without timer stepdown)

Mode spacing is now: moon-1.5-3-6-15-30-50-100%

i forgot to take pictures of the driver and the inner Head Standoff assembly Sad


i painted the head with a thin layer of Heat resisting paint to match the black host, 

first i had concerns about lowering the heat radiation, but measurements resulted i no loss of cooling

running on 100% at 20°C ambient, the lamp head doesnt get above 50°C.




Clearly, its nothing like the LT1, but so far im pretty happy with the outcome, as its my first mod that required that much of change to a lamp.

it puts out good amount of light and has a nice uniform beam pattern with almost no glare and no artifacts.

i've also printed a shade for it, and think about adding a hanger to the top.


After building it, im even more eagerly waiting for my LT1 to arrive .


Edit: added the images



Edited by: macgyver88 on 02/16/2020 - 21:54
skinny_tie's picture
Last seen: 3 weeks 6 days ago
Joined: 09/23/2017 - 03:14
Posts: 528
Location: Australia

Welcome to BLF! That’s a great mod and a fantastic introductory post. Thumbs Up

sbslider's picture
Last seen: 1 week 1 day ago
Joined: 01/22/2017 - 13:41
Posts: 1650
Location: United States

skinny_tie wrote:
Welcome to BLF! That’s a great mod and a fantastic introductory post. Thumbs Up

I second skinny_tie, nice work and welcome to BLF!

PocketSammich wrote: I don’t need this, but I want it. Please sign me up.

raccoon city
raccoon city's picture
Last seen: 21 min 55 sec ago
Joined: 10/06/2010 - 02:35
Posts: 17591
Location: रॅकून सिटी Palm Desert CA USA

I hope you have fun here, macgyver88!


Agro's picture
Last seen: 9 sec ago
Joined: 05/14/2017 - 11:16
Posts: 6936
Location: Ślōnsk

Looks great indeed! Thumbs Up

Welcome to the forum macgyver88! Beer

MRsDNF's picture
Last seen: 5 months 1 week ago
Joined: 12/22/2011 - 21:18
Posts: 13473
Location: A light beam away from the missus in the land of Aus.

Nice lantern macgyver88. Are you taking orders? Smile


djozz quotes, "it came with chinese lettering that is chinese to me".

                      "My man mousehole needs one too"

old4570 said "I'm not an expert , so don't suffer from any such technical restrictions".

Old-Lumens. Highly admired and cherished member of Budget Light Forum. 11.5.2011 - 20.12.16. RIP.


macgyver88's picture
Last seen: 5 months 2 days ago
Joined: 10/27/2019 - 10:19
Posts: 4
Location: Germany, S-H

Thanks , im happy you like it:)



tonight i loaded it with 4 fresh samsung 29E batteries, and took some shots of it in action:


lighting up the terrace:



Here you can see the dark area under the latern:


upside down, even less dark area:



I think the light distribution is pretty uniform, mostly because i copied DBSAR's very nice design of the LT1.

to be honest,before testing it i expected alot more light loss, but got a positive suprise how good the 3d printed white diffuser works.



in the most shots, the tint looks alot cooler than it is, 

i think this shot corresponds best to what it looks in real life:

on my shelf, directly below the petromax HK500 Wink


I think i will go to build one more like this, as soon as the next host arrives.

together with one LT1, they should provide me plenty of light for camping.


also a modded SRK with solid shelf and 4 sst-40 would be a nice addition, because i liked the lamp before chopping it up, i just couldnt stand the angry blue tint of the latticebrights in there.

Damn.. my bank account hates me for joining this forum Big Smile 

MtnDon's picture
Last seen: 6 hours 44 min ago
Joined: 08/27/2015 - 18:25
Posts: 4064
Location: Canuk in NM

Nice job! Thumbs Up

DBSAR's picture
Last seen: 1 day 16 hours ago
Joined: 02/11/2013 - 23:28
Posts: 6400
Location: Newfoundland, Canada

Nice work! Thumbs Up Big Smile Always great to see i have inspired others a little to become creative!

That Canadian flashlight guy & Lantern Guru -Den / DBSARlight