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

I don’t think that threads are built into the design yet for the head. As close to the shelf as possible is ideal but that will need to be balanced with final design and cost (the longer the head is the higher the cost since it uses a much larger piece of bar stock then the rest of the light).

I’d say work the threading in now
And have the finned area be one part for optimal heat dissipation
This way a relative short part of ALU is needed for the threading to tube to threading for top of head.
And a thinner walled tube can make the top part

For now I think version 0,5 is the one to go with.
And if we have the threading for top part worked in I can makeba nice presentation for the first manufacturer (5ar please make a same pic as at the top of the OP, this makes it so clear what we are after)

What kind of lumen output will this have?

~2000~2300 lumens but here is all about throw not lumen output

Yes I think we’ll push the XHP35hi to a safe point, 2500 lumens should be doable right?

2500 at least. After all this is BLF design, not a “manufacturer rating” design.

I ran some tests yesterday on an XHP35 with some nice results. Once the cosmetic issues are put behind us I will post them up.

Basically the XHP35 seems to be tougher then people have thought in the past but there is also a point of diminishing returns naturally. If I can find the money to replace it I just might push it till it pops just to see what happens.

The rest will have to wait till later.

Oh, and the new driver is coming along nicely as well…. :innocent:

I don’t think heat is going to be a factor. I love the renderings shown. I think every effort should be made to reduce weight with still thoughts toward durability.

If you read the scholarly article I posted a few pages back you will see that that is NOT all that matters.
Convection is slow and requires passive cooling to move heat away, and the spacing between fins is more important than just how many fins you can cram into one spot.
There is not going to be any active cooling or fans on the flashlight so convection needs to move the air through the fins.

Oh sorry I missed that scholarly. I’m not a good student :slight_smile:

But how do you arrange the convection. I thought convection can only take place in a fluid.

Air is a fluid.

It’s ok, you can always learn!

This

Really easy to imagine if you put tons of fins with only 1mm space in between, even though you have lots of surface area there will barely be any airflow between the fins.
That’s why CPU coolers with tons of fins use fans to move the air through :slight_smile:

So what bin XHP35 are you testing? The E4 3C seems to handle 3.11 amps at the emitter really well so far. If you need a E2 to test till it pops I can send you one! :wink:

I could only get my hands on a low bin 90+ CRI emitter myself but if you want to send a higher bin version to pop that would give up some more data for sure.

PM inbound.

Are you guys gonna test XHP35 VS XHP 35 HI vs XHP 35 dedome/shaved dome?

I will test whatever I can get my hands on. At this point that is just the C4 bin 90+ CRI HD version, I would like to test all of the above options ideally.

If I had them all I would like to do some intensity tests as well. I have an SMO L6 reflector that could be used for crude kcd testing I suppose, although it would be interesting setting it up in my normal testing location without a flashlight to drive it.

Thats why i want the finns to be ~2mm thick and 2,5-3mm space in between. This is ok aslong we are not having ultralong finns (15-20mm or so). The longest finns on the GT will be abot 5-7mm deep. So no problem with convection!

I have one question. If i understand it right the light will be having threads at 3 points (the green marked lines). Please correct me if i am wrong

Yes, this is correct.

Nope, more threads on top for the bezel to secure the lens and reflector. Unless the reflector is going to be threaded in from inside, or a retaining ring will hold it in. Either way, still gotta have an opening large enough to fit the 120mm reflector down into the head. :wink:

Bezel will be threaded also won’t it???
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Edit: You beat me to it Dale…… :wink: