Sold/Expired Interest Feeler: 18650 CREE TWISTIE

Hi guys. Never done anything like this before, so please be gentle.
Ok, it goes like this. I've been toying around lately with making a 18650 powered CREE based twistie built more for hikers/camping/general use. The idea is to have a durable light with variable brightness that will light up a tent at night for several nights or provide extremely bright bursts when needed. I'm aiming for a wide bright hotspot with lots of flood. Not going to be a throw monster. I still have work to do on the internals, but I thought i'd see if anyone was even interested before I dedicated anymore time to the project.


Ok, on to the pictures.


Features:

-1 Cree XR-E
-18650
-2 tritium slots on tail (1.75mm deep, longer than 6.5mm)
-Centered lanyard hole (for tent hanging)
-Piglet board running 500ma High and 25-75 (undecided) low
-McR reflector

I'm looking to do a run of atleast 100. If enough people are interested, i'll finish the design and get serious about pricing out machining, etc. Let me know what you think


Added 12/7/06 3:30 PM
Ok, looks like it is going to use a piglet board running 500ma and somewhere between 25-75ma for low.

Runtime Calculations:

Battery=3.7V*2.2A=8.14W
High: 3.5V*0.5A=1.75W
**estimated 80% converter efficiency gives= 2.19W
Low: 2.9V*0.05A=0.145W
**estimated 80% converter efficiency gives= 0.181W

High: 8.14W/2.19W= 3.72 hrs @ ~ 100 lumens @ led *ESTIMATED*
low: 8.14W/0.181W=44.97 hours ~ 15 lumens @ led *ESTIMATED*

I suspect these calculations are a bit on the lowside as well.

** Converter efficiency as provided by goldserve is 80-90%, depending. Good solid 85%. So, I think the numbers above should be close enough


Price:

VERY rough estimates puts this at above $100, minimum. It should be $150 or less though. Again, as below, I won't be held to this. I'm not far enough along to make this a guaranteed quote. Just a ballpark figure to help YOU gauge your interest so that I know if there is enough to completely finish the design and get ready put a signup list on the forum for a run.



Dimensions:

Spent some more time. Looks like it'll be about 23mm wide and 128mm long give or take. Walls are 2mm thick at their thickest. Some places are thinner (grooves, etc)

this is what i have wanted for a while, can you really do it?
ps. i would prefer some knurling on the head.

Just a simple interface with the flupic will run for a long long time...if PWM doesn't bother too much. The piglet can do two distinct levels, both fully current regulated.

I'd be very interested in this light. Good luck.

Looks promising and should have killer runtime, may just be interested, I will keep watching, HB.

If you have suggestions, please comment.

A clicky and a twisty may be benificial in this design.

i'm interested - but depends in part part on price, as I have other lights that already fill this niche and I'm finding it harder and harder to justify new acquisitions =)

I am definately interested as long as the price is too prohibitve. A focusable head would be nice as it is sometimes useful to have some throw in the wilderness or in the city.

Ditto to mc2

Looks cool.

Pumaman said:

ps. i would prefer some knurling on the head.

Click to expand...

I like the grooves on the head, nearly everybody has knurling on the head. Dare to be different.
Norm

Interested but that depends on the price.

Lightmania

Ok, for those of you that said you were interested
1) Would you prefer to have 2 levels (only) regulated output or a flupic that wasn't regulated?


Price: Not going to be exactly cheap. Limited run, no in house machining capability adds up. Over $100 is pretty much guaranteed at this point if i have the machining done in America. Should not go over $150 though. If I go overseas, it changes things a bit. Not sure which route I want to go.

EDIT:

This is based on VERY rough calculations and speculation. I won't be held to any of this later. Just trying to give you an idea of what i'm looking at.

Regulated output with 2 levels.

I would pick the 2 regulated output levels. At what brightness do you have in mind? 50-60% and max?

will it be hard anodized? O-ring for weatherproofing?

Lightmania

added: I'd love to see minimum brightness, too. Say, 10-15%. But that might be asking too much?

I'm in for one. Hope the walls don't get to thick to keep it slim.
That 3/4 shot makes it look tapered. Illusion of the knurling perhaps?
McR17 reflector? And definitely 2 levels

T

The walls won't be grossly thick, but they're not going to be paper thin either. I want it to be able to take a beating. It isn't tapered. Must be an effect of the angle and the grooves. It will have an McR reflector, which specifically is unknown right now. But it won't be cheap plastic. McR


I'm a bit torn about the two regulated levels. It seems this is the route most people would want, but it causes a design problem for me. I wanted this light to have the ability to be VERY bright when needed, but have very long runtime when needed. With only two levels that puts it at MAX and something like 5 or 10%. Seems a bit extreme. I guess I could make the bright 'medium' and instead of something like 2 hrs runtime give it 3 or more hours runtime with a low low.

I don't know. I want to hear your opinions.

If it was a light just for me, I would set the output levels to medium and low. Say 70 or 80 lumens (350ma) and 5-10 lumens. Would give some pretty ridicululous runtimes and a decent amount of light.

With the cree, LOW is all I use for my lights..that is 50ma. At 500ma, it beats out the high on a HDS 60. Using 18650s means that you will get at least 4 hours from high. More than plenty.

Ah, thank you goldserve. I was halfway through editing my last post with some calculations about runtime vs brightness, but firefox crashed when I opened the CREE pdf

I think i'd make the high drive level 500ma. I had already sorta decided on 500 on high, but was up in the air about the low. I'm thinking anywhere from 25ma to 75ma to the led.

I forgot that small runs makes things mucho expensivo.
Have you thought about taking an existing body that would take a 18650 and doing a retrofit or drop-in?

Btw, I for one would go for a 2-stage (or 3-stage), via twisty. Clicking through modes, I realized is not for me, nor is it very good or useful for high-stress or quick-draw situations. With even a 3-stage twisty I can get to any level I want in about .25 second.