(prototype) the GT Mini

My GTmini showed up today. So far quite impressed with it.

After three weeks I finally got my Mini GT NW today. Light looks great however there is an issue with it. When in turbo or top of ramp and double click to turbo the beam changes from NW to CW with a purple corona and then smoke starts swirling inside the reflector. Obviously this isnt’t right. I bought from the Group buy here on BLF. Not sure who to contact.

It sounds like the led is overloading/overheating due to bad soldering to mcpcb. One other person reported the same. I would contact Neal or M4D M4X.

I got my mini gt today. Yay… both mini gt cw and d1s cw measured the same lumen… so both are equally good or the same.

This might be useful to buyers from united states… i recorded banggood shipping time… all free standard shipping. I counted the days when they start shipped.

Flashlights 10 days
Flashlights 11 days
Flashlights 9 days
Flashlights. 14 days ( wild fires delay ? )
Flashlights. 11 days

Wonders never cease!!

Mini GT was………

  • Ordered & Paid for 9 July 2018.
  • Shipped 2 August 2018
  • Delivered today, 27 August 2018

An impressive little light to say the least…… :+1:

Possibly the led has not been flowed onto the MCPCB correctly.

25 days ? Thats hella long… atleast mini gt get there safely…

Yep… there are several of us that bought these through the Pre Buy/Group Buy/whatever it was………. that the shipping time sucked. :smiley:
No complaint… just fact. It appears that group of packages either was truly on a slo boat or just sat around somewhere for a couple of weeks with no movement.

But… such is life . :smiley: :smiley:
At least it arrived in one piece & working. :wink:

That is what I’m saying. When it goes to turbo, the heat can not get to the mcpcb fast enough.

Got mine today as well. Played around with a charged 30q when I got it. No smoke or unfocused reflector (that sounds horrible, sorry man). It looked great on the wall.

After the included 30q was all charged up I stuck it in my sphere. Only got 1,101 lumens at startup and 1,049 at 30 seconds. Mine is the NW variant.

I did notice the light seems to be made to accept protected cells as the 30q is not as tight end-to-end as other 18650 lights. Springs are not compressed without load, just not as long as I expected.

I may bypass the driver spring to see if it helps.

I’m not really let down too much, as i’m getting 88% of rated output. I’d be happier within 10% though. I’ll try a few other 30q and maybe a vtc5a to see what it might be.

It’s pulling 5.32amps, at start, in turbo.

I did get 134,524 candela at 20’ measured with the same battery fresh off the charger, which is right on par with the claimed 135k (within 1%).

What sphere are you using? Obviously they can vary the output readings.

If your measuring 135kcd from a NW, you have the most powerful NW yet. It kind of suggests your sphere readings are low.

Is the 5.3A at startup? It’s better to measure at 30 seconds or sooner if it stabilizes. Maybe you can squeeze a bit more output with a driver spring bypass.

I measured 1390 lumen @ 10 seconds… TA tube. Cool white. Sony vtc6… jason, is that too high??

Are you asking me to compare my TA Lumen Tube to yours? Do you suspect your tube is reading a bit high?

I adjusted my TA Tube to make it read consistently to my Maukka calibration light. I had to reduce my output by more than 32. I had to reduce it by 39.

Your lumen reading is about 12% higher than mine (well within tolerance of the stock TA Tube). It would be best to also compare the amp draws and the candela. If your also drawing 5.5A and had 148kcd, then your tube might be reading a bit high (compared to mine).

If your drawing 6A and get 155kcd, then your lumen numbers might be about the same as mine, your just getting higher output from the light.

I see you just ordered a calibration light from Maukka. Have you received it yet?

I do not believe my tube is reading high, as I have not tampered with it… two fenix lights measured 960 and 1027 lumen for the stock 1000 rated…

I am just curious what you guys getting… I ordered maukka calibrated lights and should be here soon.

I do not know how to measured amp draws nor have a device to do it.

This is very easy to do. Most folks on the forum prefer using the Uni-T UT210E meter. There was a group buy as well as coupons a while back. It’s usually around 30 bucks. You can take off a lights tail cap and connect the battery with a loop of wire to the battery tube. Then clamp the meter to the wire. The light works normally and you can measure the amperage. This is how you would estimate output if you didn’t have an integrating sphere.

Neal is the seller ;)

I made a new email: CS@m4dm4x.com

that is redirected to Neal and a copy reaches me

I have just experienced that kind of behavior from a Sofirn C8T: in low and medium mode, the tint is NW, when set to Highest brightness mode, the tint changes to cool-bluish tint, and there’s smoke swirling inside the reflector… I reported the issue to Sofirn and sent a lot of pictures (even asked me to put more thermal paste beneath the LED board, which I did, but it didn’t solve the problem.) Fortunately, Sofirn send me a replacement LED+board, which I’ve installed on the Sofirn C8T, and now it works properly (no tint shift when changing from medium-to-high modes and no “smoke swirl” in High mode.

I think the issue is the LED is not ‘baked’ properly into the LED board (which I don’t know nor have the equipment and skills to correct that), so the LED gets hot and becomes bluish (purplish in your case) — at least that’s how I understand the issue to be…

@Wolfstyle:

When opening the bezel of my GT (in the process of checking a faulty driver switch) the led was sheared off the board by transfer of the twisting action to the reflector and centerpiece. This may or may not be related to what happened to you. Shearing off a led has not happened to me before so it could be that Lumintops reflows are on the edge of not hot enough or too little flux, resulting in insufficient solder joints that apart from being weak may also not transfer the heat well enough.

Mine is a 17”round sphere, calibrated using maukka lights, using a drmeter. It’s got two baffles preventing direct exposure on the meter’s sensor. Using an HS1010a at 20’ for the candlela.

Same exact measuring setup reads 2008 start lumens (1886 at 30s) on the catapult v6, with 174kcd.

Also took a hotspot pic at 4 feet. Both on low settings. GT mini is NW, v6 is CW.

Blf gt mini vs catapult v6 hotspot

The gt is a good deal smaller. Measuring on the wall, I got about 3” on the mini and about 4.5” on the v6.

Just tested the mini again with vtc5a, and got 1057 at start and 1013 at 30s.

Here’s a few pics of my sphere, for reference:

New sphere

edit: just bypassed the driver spring with 20ga and got 1195 at start and 1081 at 30s. Also stretched the spring out a little and about 2 coils had been soldered together at the board side. Spring popped right out and gave about 7mm of height, compared to about 4mm out of the box.