Lumintop GT4

It’s not going to use a buck driver though.

A 250W-300W flashlight sized buck driver would be extremely expensive, where a FET+linear regulator design would still work adequately with 4X XHP70.2s.

And besides, the 1mm2 Olson HX Boost only comes in 6000k+ variants, which look way too blue.

Lumintop could easily offer a CW XHP 70.2, and a NW 4000k XHP70.2 model, which would easily satisfy almost all customers.

It will be using a beefed up version of the GT70 driver basically, so 2 channel FET driver.

A buck driver would be nice but a ~40A buck driver is no simple task and it would be very large, I know this from experience on a light that never went public.

The boost HX is an interesting idea for a future version of the light but it will not be something done at first that is for sure seeing as they are not even out yet.

Can it run on 8 AA?

lol, not exactly.

Ohhhh shoot…lol…cant wait for it….

Is the head the same size as the BLF GT? Is the heat sink the whole head? Looks to be one piece, any info on that? Any side pictures to see how deep are all the fins?

Yes, same basic size as the GT / GT70.

Yes, all those fins on the head are used for heat sinking pretty much.

Here is one of the earlier CAD designs, I can’t find the latest one at the moment but it as only minor changes.

The cooling on this light should be quite good to say the least.

Thanks TA! :beer:

No idea, looks great though! Just saw it on FB this evening. Hopefully should out-do the old Shockers - think the best I got was over 500 kcd. Some slice&dice action on those biggies should do.

4 xhp70.2s in huge reflectors vs 9 xhp35 HIs in smaller reflector wells would be an interesting comparison. seems like the gt4 will make for slightly more lumen but slightly less throw.

Well, for one, it will have better QC, replaceable cells, non exaggerated specs, NarsilM.

And where did you find an R90C for 200$US?

The lowest price I’ve found with a coupon is 280$US.

It will be more reliable than the R90C specially at the driver, step down is user-controlled, probably brighter, much better heatsinking, and most likely without the fogging issues of immalent lights.

Sadly max output will drop accordingly to the battery level, being a direct drive setup.

And can be used with 8 18650s for much better runtime.

And you can get the light in Neutral White rather than Cool White.

This light was first planned WAY back when the GT was still in the planning stages. Needless to say things have progressed since then and it is not quite as revolutionary now as it would of been 2 years ago.

At this point, yeah there are other lights that would be direct competition for sure. How they would compare is something I can’t know without some testing though.

Lumintop finally said they want to proceed with this project and I was sure not going to say no lol.

Based on VOB’s lumen readings from the R90C though, I do expect higher lumen output from the GT4. My goal is ~20k real lumens or more.

Imagine 4 CFT90 in this thing. Power draw and cost would be unrealistically high.

4 2mm white flats would be nice as well.

Sure.I’ve got it at $290.00 .

CFT90’s would be awesome for the throw but the power draw (and light output) would be a bit less.

I wonder how much the head weighs? it must be alot more then normal gts as it looks quite beefy in the pics. So a runtime on highest should be like 5min atleast or so based on how it looks ?

If it has good runtimes on highest then it can compete with olights and acebeams monster lights then if the price isnt too high also.

It is not extremely chunky inside the head, a lot of volume is converted into finning, but fins have mass also of course, so yes, the head has a bit more volume and will be heavier than the GT. I’m really curious about what the sustainable light level will be actually, large flashlights have an unfavorable volume/surface-area ratio so scaling the power up from a smaller light requires disproportionate measures to create extra surface area (=fins). This is attempted in the GT4 but how the final sustainable output proves to be is a surprise. I hope for over 10K lumen with the head kept under 60 degC. (that will drain the batteries in say 45 minutes, so sustainable is relative :slight_smile: )