Tomogchi's home made flashlight for OL contest

So i had an idea for a no cost build. From things around the house/my electronic stash box. I like the idea that you can build something from nothing. unfortunately i have no access to good tools other then myself right now. Also, if you think mines poop enough for you to enter and it can do better -frickin sweet! show me, id love to see more in here.

Its been a year since i built anything…life has gotten way busier then id like. I actually had a light built last year for the modified category, but was unable to make a type up for it in time. since then I’ve spent a whole year thinking about this. I have 10 hours over the course of the last 2 days cobbling it together. we will get this one finished and submitted, bear with me…

0 cost, 0 real tools (flush cutters, diagonal cutters, couple drill bits, soldering iron, 63/37 solder, iso alcohol, paper towels, 60 grit sandpaper)

I was going to use sch 40 pipe for this but decided that would be a cost as I have none on hand. Improvise. Adapt. Cobble. That is how it goes, right? :slight_smile:

The build list goes something like this:
(pic 1)
mtn 17mm ddfet driver
osram 1mm2 on 20mm copper pcb
fresnel lense
3 tin cans, Hunts tomato paste, great value carrots, Busch beans (sorry only two pictured)
3 samsung 30b cells
tp4056 charger
3 red 1206 leds
3 1206 150ohm resistors
aluminum insert/spacer
random tiny fan
20 awg silicone wire
cardboard (rachael ray wet dog food box)
maxwell coffee container lid
handfull of 3mm screws / nuts / washers
random tail switch
1 plastic straw
1 16 oz great value water bottle cap
some cermaique 2 thermal paste
Enough hot glue that RED GREEN himself would be proud

on to the build………

(pic 2) drilled 2 holes into the alum inser and the bottom of the can, to hold the led/heatsink/can together. that mightve been for a triple, but not anymore

(pic 3) drilled an additonal hole for wires, placed a straw in the hole first to act as conduit (sharp edges)

(pic 4) well, if youve never met me, i cant draw a circle or a straight line to save my life… drilled a bunch of holes and then used flush cutters to remove the rest of the bottom of the can

(pic 5) fresnel lens (from a broken discovery kids art projector if your curious) being cut down to size… with a drillbit. almost broke it, two small cracks on the outer edge. such is life, right?

(pic 6) not pictured is HOURS of sanding to get it just right (circles are not my friend). clogged sandpaper very often.

(pic 7) fresnel lens fits, yay! that sanding took too dang long.

(pic 8) just focusing the ceiling light, about 6” off the ground

(pic 9) Back to the can, time to get the thermal paste out and assemble stuff.

(pic 10) didnt want anything to short out, so i cut out two washers from the water bottle cap. had a nice channel to tuck a wire, one less thing to glue!

(pic 11) 3 samsung 30b batteries, laptop pulls. still test approx 2600mah. I wont show the pictures of soldering the cells (dont do it its really bad pratice, you should spot weld them).

(pic 12) mmmmmm begins the hot glue adventure. Go figure the glue sticks we have are clear, but dry yellow. Oh well full send. Lens glued in place

(pic 13) mtn 17mm driver running guupydrv rev 2. gotta remove the spring. well, guess i dont have too, but i will.

(pic 14) tp4056 charging module hot glued into place. I applied some kapton tape to the back of it before i glued it in.

(pic 15) random switch i found in my drawer. back is covered in kapton tape, then hot glued. Also cut another piece of straw for conduit here.
who would of guessed, it ended up being a forward clicky switch. still shifts through modes so works for me.

(pic 16) mmmmm more glue to keep things in place. it was at this point in writing this that imgur wouldnt let me upload any more photos. if abload doesnt work ill try to figure something else out… thanks google translate!

(pic 17) aux lights are cool, so why not. asked the household what color, and red won. 150ohm resistors, i dont need them being SUPER bright. theyre actually quite bright at as is @ 10ma.

(pic 18) isnt it pretty? i am such a sucker for aux lights.

(pic 19) guts n glue

(pic 20) cut can #3 to hold can #1 and #2 together. Hotglue to ‘temporalily’ hold, and some bolts/nuts to make sure it stays tight. All those gaps? you guessed it. HOT GLUE!!!

(pic 21) used some thick nuts as washers to keep the can ‘centered.’ that gap? yeah dont worry we got that. points to hot glue

(pic 22) its so crudely alllliiiivvveeeeeeee. it needs a name, and i havent figured it out yet. frankinbeans? idk

(pic 23) i uhh… didnt realize the particular placement of the light prior to taking the photo, and if i offend anyone - my apologies i will remove.

(pic 24) heres the beginning of the base of the unit. cardboard base, gotta make the fan fit and actually function.

(pic 25) added a piece of cardboard to force ventilation through/ around the can. it wasnt working right without it.

(pic 26) so i decided maybe the usb port should have a cover of some kind as its exposed right now. found a empty coffee can in the kitchen scoreeeee. cut a flap and bend it to cover the port and slather on that hotglue!!!

Now you might be asking, is that it? nope, still stuff to do. well, i seem to be missing a few photos, such as a photo of gluing the plastic base to the cardboard, and gluing that to the base of the light. i apologize about that. Im writing this up as the paint is drying. I still have to peel the tape over the lens and recharge the cells, and im not sure if im going to change anything. The sun has about set here, and hopefully it will be dry enough to atleast get beam shots with tonight. If not, it may not be until monday evening (late). But we will see what happens.

(pic 1) Remember when Henry ford said “you can have your car in any color you want, as long as its black.” well, that applies here. It almost doesnt look like its 50% hotglue when its painted black. Fortunately for me painting is a skill i actually have. May not have the ability to draw a circle or a straight line, or cut either of them - but painting i can do well.

(pic 2) You can see the aux lights peeking through the kapton tape here. I think its really funny how kapton tape is a better ‘painters tape’ then painters tape. There is no bleeding through kapton tape, unlike painters tape.

(pic 3) Frankinbeans looks great in black actually. its a shame this rustoleum paint takes forever to dry. the cheap walmart paint dries almost instantly.

(pic 4) oooooo pretty aux lights.

(pic 5) Its very much daylight here (duh), yet the aux lights can be seen on the ceiling with no problem.

(pic 6) I cant get the potato (phone) to take a correct photo here to show what i see. however, very little rings in the beam (expected way worse)

(pic 7) another attempt to get a good photo to show emitter shape.

(pic 8) While it was drying i took it out for a singular photo last night. this tree is 250 foot away and approx 60’ tall. For a bunch of ‘garbage’ this seems to actually do really well!! you can see the defined emitter shape in the tree here. im excited for when im able to actually stretch this things legs!

(pic 9) This is a photo down through the fan (base). the blue is the tp4056 charger indicating the cells are fully charged. They were also charged when the project started, but focusing the emitter took forever. the red you see deep down is the aux lights through the straw-conduit.

Now we need some real beam shots and something to compare it too… that is something i wont be able to get until next week.

also reserved should i need it

Perla!! it should have decent throw.

Now that is a can light!

Frankinbeans! Hahaha.

Cool build idea.

. well thanks guys. im def not at the level of craftsmanship that you guys are, but i do enjoy making/braking/modifying things to my liking. its just fun to make stuff. Its even better when the other half looks at you and goes “you need the cans for WHAT!?” and rolls her eyes. she puts up with a lot :slight_smile:

This should enter the OL Contest :laughing:
Nice idea, well done :wink:

Great build ! I think Frankinbeans is appropriate. :+1:


real can flashlight :smiley:
well done, sir!

Nicely done sir.

Indeed Red Green would be proud! But he would’ve used duct tape instead of Kapton. :smiley:

Tomogchi, I absolutely love the concept and execution of this build!! There are plenty of tutorials floating on the internet about making flashlights out of junk, but they are all of the 5mm LED variety, while yours performs at the level of enthusiast lights! Just eyeballing the diameter of the lens I'd say the throw is easily 1km+.

I did a Fresnel build out of a cardboard box with similar intentions (you commented on my reddit post on it!), but I used a full Convoy S2+ for the light engine, while your build uses 100% scrap for host.

I notice that in the treeline beamshot you posted, the beam is not just a well-defined square but has a huge diffuse corona around. This might indicate the possibility that the Fresnel lens doesn't have enough precision to correctly focus a White Flat 1 emitter--my own build had an additional condenser lens that increases the apparent size of the emitter before its light reaches the main Fresnel lens. But doing the same would involve adjusting the focus, which might be impractical for your build. Another possibility is to use a higher-powered throwy emitter with larger die size, such as SFT40--the lens should have enough precision to focus that. Plus, your fan-cooled heatsinking setup is wayyy ahead of mine (Convoy S2+ smothered by cardboard), and should have no trouble handling a higher power emitter.

In any case, I'm rooting for your entry for the OL contest!

@qreciprocity i remember that build well and appreciate the input. Your correct in noticing the beam isnt perfectly square, but kinda diffused around the corona. This fresnel lens is by no means the best but im not sure its totally at fault. focusing the light was very, very tedious. i think that took the most time. It was the first lens of two in a well used and broken discovery kids art projector and then abused by me with a drillbit to cut it. Im SURE theres a lot of user error here but for a bunch of nothing, it does something rather well… i had originally toyed with with the idea of a condenser/collaminator lens on a sft40 or a ‘rosy’ xhp35 but the sft would have crossed into purchasing stuff territory and i didnt want to ‘waste’ my only xhp35. I will say the crude heat management actually works well and the light throws very well for what it is. I already have ideas for a next one, including better lenses (sure, we’ll blame that :smiley: )

As for all the kind words from everyone, thank you!

I picked a really rough rival for beam shots and in hind sight maybe shouldve used a convoy c8 or a l2. instead i went armed with the original blf gt (stock) and my camera CLEARLY favors it :sunglasses: . The lake i shot at is the furthest straight shot around i can really find without driving far distances. google maps says its just shy of a half mile, 2600 feet.

(picture 1) it is really hard to beat the blf gt in terms of performance. obviously this is nothing for such a light and my phone has no issues showing this

(picture 2) another shot of the blf gt on the surface of the lake. it is a spectacular light.

(picture 3) here we have the frankinbeam/n (still havent decided yet) on low mode. actually surprised it could reach the edge on low

(picture 4) and on high it clears the lake with no problem. It may not be perfectly focused, but its enough to make me giggle!

(picture 5) i tail stood the light and walked away to take this photo. the tree you can vaguely see is about 55-60’ tall and part of the beam catching on some fog? low clouds? that started to roll in. I’d actually love a foggy night to go out and make some light saber noises.

My phone really struggles on low light shots, and while photos 1 and 2 look much closer to real life, photos 3, 4 and 5 are much grainier/duller then i see in real life. Im going to try to find someone with a better camera and try to borrow it for a night and re-upload said photos, but seriously this can-light does really well for a cost of 0.00

Very pleased with the results!

Extremely nice beamshots! BLF GT is in its own class; I'm sure your build can steamroll any c8 setup in the throw department.

Looking at the beamshots reminded me that there is another explanation for the corona around the square--this can happen when the emitter is sitting behind the focal point, i.e., too far from the lens. This is actually a common problem when one tries to calibrate focus on an object that is too close (within 50m). The feature of the beamshot that gave this away is the double-cone shape (beam converges at a finite distance and then diverges), which indicates that the emitter is too far behind the lens. Re-calibrating the focus should result in noticeably more throw--by eyeballing the shape of your beam, I won't be surprised if it more than doubles the intensity.

It seems that the heatsink assembly is held down by screws which are easily removable--if that is the case, one might be able to move the emitter closer to the lens by padding the underside of the heatsinks with something. But you probably have a better way to do it.

Regarding poor low-light camera capabilities: if your camera is able to manually adjust shutter speed (I believe almost all Android phones can in pro mode), 1/4 seconds or above is great for beamshots. But if your phone is a OnePlus N200 then it's beyond salvaging...

Another tip for beamshots is to adjust the white-balance to the lowest possible CCT. This makes blue--the color scattered most by air--stand out more.

I ’m glad you made it to the OL contest :wink:

Nice invention :smiley: