Lumintop BLF GT --> BLF GT90 conversion !

This thread is made possible with the true BLF community spirit, with special thanks to member Chibim, Gchart, Oweban and last but not least Lumintop!

I was dreaming for a while to own a GT90, but since i am frugal (which is why i am member of BudgetLightForum) I did not want to spend 300$ on a flashlight.
Texas Ace mentioned in the GT90 thread that he could get GT90 conversion kits, but they were still 120$, whith additional shipping costs, which was a lot more than i had hoped for.

Another minor point was that i actually sold my original GT last year, so i still needed to get a GT.
So that left me with three options

  • Get a GT and buy a TA/Lumintop conversion kit
  • Get A GT90 with a good deal
  • Get a GT and try to buy parts from Lumintop

Frugal as i am, i tried to PM some BLF members asking if they were willing to sell their GT (for cheap), some people were willing to sell them but i was looking for the best price, so i decided to wait

I tried to get a good deal on several places and even begged Lumintop, they could give me some discount but the grand total was still 280$, so still not the success i was looking for.
I have asked Lumintop if i could buy i GT90 conversion kit directly from them, but that was practical impossible. I could buy a driver and LED but the carriers were a problem.

Since i have much contact with member Chibim, Gchart and Oweban, they were willing to help me out, Chibim sold me his GT for a more than fair price, Since the carriers could not be bought from Lumintop i needed to find another solution. Member Gchart was willing to design the PCB’s for the GT90 carriers, and member Owen helped him out with the design and dimensions. With the design i was able to order the carrier PCB’s, which I ordered from JLCPCB, and they were actually quite fast and not unimportant, cheap :wink:

Lumintop offered me the MCPCB with LED and driver for a good price (actually Member Chibim already ordered the driver) so with all that sorted i was able to mod my GT!

So the first thing to do was to disassemble the carriers and unsolder the springs

Solder them onto the new PCB

Assemble it back again
(And made a new brass pad for the driver, since it did not come with one, and i did not want to take it off the old driver, because you never know if it will see any new future use sometime. I made it from an old brass water tap valve, where i used my hacksaw to cut off the flat end of it. Some serious elbow grease)

Number 1 finished

Number 2

Carrierss assembled

Check functionality

Unsoldered the leads from the XHP35 and cleaned the shelf

Unsoldered the leads, since they need to be transplanted

Put some thermal grease in between and put it back together

driver side


One stupid thing, the hole diameter for the screws is larger as with the original XHP35 version, so they do not hold down the MCPCB, they’re probably only there for aesthetics
since they do have zero function now. :person_facepalming: As mentioned by Kawiboy “(over here)”:Luminus SBT-90 gen2 5700K tested (SBT-90-WDS-F72-SA600 SA-H4, from Neal) - #66 by KawiBoy1428 it still acts as an anti rotating feature

It shows a sign of life !

From the outside it’s still a standard GT :wink:

But experts know the difference

i like it!

Really would like to test it out in the dark now, but unfortunately it started raining and there’s thunder as well, so that will have to wait

Also thanks to Henk4U2, who was hesitating to sell his GT, and sent me a message after 2 months that he had to think about it and was willing to let it go. The only thing was a bad timing, since i just bought Chibim his GT the day before!

Thanks again all guys, really appreciate it!
As mentioned before, that’s true BLF spirit :blush: :beer:

For those interested, here are Gchart’s carrier gerber files:
GT carrier negative

GT carrier positive

Good stuff Yokiami!

edit: YokiamY :p

Looks great, and I’m jealous! Have fun to night, it is dry now :slight_smile:

Yeah, i’m jealous already for your GT4 :wink:

Awesome mod, yokiamy!

Wow, that is some modification.
And the best part of it (for me), it is hardly visible on the outside.
It is like a wolf in sheep’s clothing.
But since the original GT was no sheep at all, one might call it a dragon in wolf’s clothing.

But to be honest, there is a vital thing missing: beamshots.
For the proof of the pudding is in the eating.
Which brings me to another (food) expression: you can’t have your cake (GT) and eat it (GT90).
So you definitely need an other GT for a side by side comparison.

Just so happens that you have one for sale? :wink:

Terrific work on the mod Yokiamy. And to boot it works. Even better. :+1:
I love reading about mods like this where members come together to help another. Nice work all round. :beer:

Thanks for getting the measurements to me, oweban!

Hm, coming to think of it …. :innocent:

Sweeeeet!!! :o
I don’t have use for one of these, but I’ll be happy to see your beamshots when possible!
Nice “community work” :face_with_monocle:

Great job on the conversion mod! Does anyone know if Lumintop will make a GT90 mod kit in the near future? The GT90 is to rich for my pockets as I am sure for many others.

It’s a crappy phone pic, but ITS AWESOME !
It feels like firing a bazooka (at least, that is how i’d expect it to be, i’ve never really fired one)

I felt like a deer hunter (spot the deer)

That looks amazing! The spill and beam are incredible :open_mouth:

That’s a nice community effort and result.

You can gain more output if you take the lens off STB90.2. Vinh54 has a how to guide

For anyone that might be interested in doing this mod, I would recommend doing that yokiamy did and using the Gerber files he linked to over at JLCPCB or PCBWAY. I like Oshpark but for larger boards they can be expensive. But if you’d like to get a view of what the boards look like, here are Oshpark links:

Nice, what was total build cost?

100€ for the GT, driver and mcpcb with SBT90 65$, PCB’S for the carriers were 6$ (+ additional shipping costs)
So around 180

Looks good and well done. That’s the cheapest GT90 ever!

Impressive :o
The deer must have thought he was going to be abducted :smiley: