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

First, I’d like to point out that not all parabola’s are created equal. There is no fixed parabolic formula for flashlights, which is why 200 flashlights on my shelves all have different profiles. There is simply no such thing as perfection. It all starts going wrong when we leave the pinpoint of light at the source and spread out the die surface, that gives us multiple points of output and the parabola suffers when trying to converge the beam.

The Nitecore P30 is a nice example of being different, at approximately 43Wx40D it approaches that “square” ratio and as such it throws very well for a smallish light, illuminating out at 670M with a mere 1070 lumens from an HI. I’m not prepared to cut my TN42 reflector in half so you can see an example of a thrower’s parabola (approx 89Wx88D), nor am I willing to cut the SR-90 Intimidator’s as it too can do over a mile…. and at 88Wx60D it’s more of a bowl than you’re describing as perfect. At any rate, having had several different lights in hand that attain a mile throw, I can tell you for a fact that each one had a different parabolic formula.

All we can really do is wait and see what reflector is available for our need and test it to see how it performs. We just might not be able to get a proper reflector that does what we want. Not without designing it first.

I have a 200mm convection lens from Edmunds, it lists for $135 for the glass lens alone.

Conclusion is if you have more cooling fins you have more square area of cooling to the surrounding air. I think if the cooling fins can be cut deeper. And they have a bigger diameter you will have the best result. Is it easy to do the thermal analysis again with wider cooling fins and in between the fins deeper milled (smaller diameter). PS I like the .5 style

PS2 I think there is always some airflow if you are outside walking with such a flashlight.

Really? Now that is (a very different matter/project alltogether but) very interesting!

I’ll be PN-ing you soon. :wink:

Grtz
Nico

The lower fins can be cut a little deeper I agree, the top fin needs more meat behind it so that the heat can easily move up there and beyond, plus for strength…

Working on pictures is not one of my skill but i tryed it.

It is not really straight. But i think it is going in the right direction.
For me a flashlight can not have enough cooling capabilities. Bacause my plan is to update the LED as soon as a new LED is on the market that can outperform the XHP35 in throw and output. And then every bit of extra cooling will be appreciated.

I kind of agree fins are good

On the above pic, I assume the widest part of the head attaches to the finned area just above the top fin right?

Ah and Dale, I wanted to say it is very nice to have a big gun like you thinking along, reassuring :wink:

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: