Asian8640's Handmade Class: 9th Annual Old Lumens' flashlight making contest entry

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Asian8640
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Asian8640's Handmade Class: 9th Annual Old Lumens' flashlight making contest entry

I skipped last year due to lack of time, but I have some free time and will partake in this year’s festivities. I’m not entirely sure exactly what I want to do this year, but I’m hoping to use copper as the primary material so I can practice soldering with a propane torch. I’ve never soldered anything with a propane torch before so this is going to be something new for me. I’m also considering using aluminum as a base due to the lower cost, however I’d have to do stock removal for shaping the light as I have no way of stamping/riveting/soldering aluminum sheets. I am also worried about boring a hole in aluminum stock without a lathe and do not have a drill press that could take a 19mm drill bit. We’ll see as soon as I can put pencil to paper and jot down some ideas.

Things learned from my previous build:

1. If I do a lantern, it must have a wide base for stability purposes. Using my old lantern for 2 years has shown that it has been too easily knocked over despite the weight of the AA in the base.

2. The sliding switch I used prior has had terrible contact reliability in the long run, flickering and unstable brightness when moving it around being the primary result. A pity as I no longer consider those switches as viable for any project and I hate to waste materials.

3. It’s better for a light diffuser to be made out of opaque material to more evenly distribute the light. Technically I knew this while building, but was unable to procure a suitable diffuser in the correct size and shape that I wanted. Closest I could get was a shot glass so eh…

4. I need to find a more reliable image host for my images. 2 years on and lensdrop has deleted all my images. Might have to go back to imgur.

Edited by: Asian8640 on 12/01/2021 - 18:18
MtnDon
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Great! The master list of entrants has been adjusted to include you.

MtnDon
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Wow, I had no idea. I do use an oxy-acetylene torch. I do have 4 full cylinders and one almost empty, of genuine MAPP left from a case I bought a very long time ago (probably about 2007) for some special job I couldn’t easily transport the big oxygen and acetylene cylinders to.

There is a huge temperature difference between true MAPP and Map/Pro. MAPP = 5300 F vs 3730 F for the cheaper to make Map/Pro.

I guess I am guarding the use of those 4 MAPP cylinders very carefully.

Asian8640
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Sorry for not uploading anything yet. I’ve been busy hammering away at the flashlight but haven’t really had much time to work on the write up. I settled on a fully copper flashlight with the vast majority of it it made from working and manipulating a single 3/4” copper pipe and fittings. It’s 90% finished. When I get time this weekend, I’ll get that write up completed.

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Looking forward to seeing something here Thumbs Up , I have been a bit slack, but it’s all well underway now!

wcddesign
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also looking forward. love my copper light.

Asian8640
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Good grief… I’ve been lazy in posting. Technically I’ve been busy, and I probably should have uploaded posts as I went, but I guess that’s behind me now. The light is complete and all that’s left to do is regale the rest of you with the tale of what I did and how I did it. Let’s start from the beginning. The original intention behind the light was to use up the rest of the parts that had been in my parts been for 2 years. Ever since I had made my last entry into the 7th Annual Flashlight build contest, I have built a total of zero lights and have done a reflow/emitter swap on one. As such, there were just a whole bunch of extra parts lying around and getting no use. I am a fan of having spare parts, but considering I now have more than enough flashlights in the color tints and CRI I wanted, the chance of the spares getting any use before technology moved on was slim to none unless I took active steps to change that.

Let’s start with those leftover parts. I had every single Carclo 20mm TIR that they made and was itching to use them as their use in an actual flashlight never occurred due to the fact that they required TIR holders to center and the holders had clips on them that prevented them being flush with the surface above them. For 3535 LED’s, I had 4xSST20 2700k 95+ CRI emitters from Simon@Convoy, 4x Samsung LH351C 3000k 80+ CRI Ceramic emitters, and 2x Nichia 219B SW45k. For DTP PCBs, I had one 20mm triple and one 20mm single from MTN Electronics. As far as drivers were concerned, I had only one, a 1.4A Biscotti driver from Convoy. Since I had the optics, PCB, and LED for a single emitter light, I thought I’d go with that. The first problem arose with the 20mm MTN DTP PCB. While it looked like a Cree aluminum DTP PCB, the cutouts on the side were just a little bit too wide to fit the Carclo TIR holder. So, I clamped the PCB to my desk and filed it down until the holder fit.


Another reason why I initially went for the 20mm emitter plus holder was how perfectly it fit inside the 3/4” copper fittings that I would be using in this light.

Eventually, I had to take care of the issue that was the little tabs on the side of the LED holder.

Turns out, it would never truly fix the problem and I would abondon the TIR’s for multiple reason, but I hadn’t yet reached that point in the build. At this point I was still fighting just to acquire materials.

My original intention was not to use imperial pipes, but metric pipes as everything about flashlights is produced in metric. However, there wasn’t a single supplier within 100 miles that had copper pipe of the correct wall thickness, or any metric copper pipe in general. I spent a whole week trying to source metric copper pipe locally, but to no avail. I eventually gave up and decided to work with a single piece of 2’ long, 3/4” diameter Schedule L copper pipe along with its fittings.

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When you buy fittings for pipes, it is important to pay attention to fit and finish. When I purchased my fittings, I purposefully chose fittings with sub-par fit and finish so I could practice working on evenly filing. These 3/4” fittings without a stop were purchased from Home Depot. The equivalent fittings from Lowes were a few cents more expensive and had a much cleaner finish to the edge. Looking back, it is better to spend a few extra cents than the time it takes to neatly clean everything up and make it even, because with my lack of skill with hand files, it is highly likely it will never be perfect.

In order to clean it up, I started going through Old Lumens’ videos for inspiration on how to make a nice flat surface. He had a technique of using the edge of tape, lining it up, and then filing down the material to meet the edge, so that’s exactly what I did. However, I started off making the mistake of using a file with a width less than that of the diameter of the pipe. I had to constantly turn the pipe to ensure even removal of material. It was time consuming and annoying. Eventually, I gave in and spent the $7 on a correctly sized file, but that wasn’t until mid way through the build when I started valuing my time more than the cost of a single file. In order to make sure the piece didn’t move, I used a table clamp to make sure it didn’t move in the vertical and one of the horizontal axis. Due to the fact that I couldn’t get an even grip on all sides as my cheap clamp didn’t accept interchangeable jaws, the tape provided two other functions aside from being a guide for the final height:

1. A malleable material which the clamp could grab on to
2. Protection of the surface of the soft copper pipe against the hardened steel of the clamp.



After cleaning up the edges of the pipe, it was time to make the pill. I ran into multiple problems for this step. Let’s start from the beginning. The inner diameter of the copper pipe is 20mm. In my design, the pill must fit into the top of the flashlight barrel, and the surface of the pill where the direct thermal path printed circuit board for the LEDs is attached to provides the lip that prevents the rest of the pill from slipping further into the barrel. This is the only part of the build that is required to be flat in order to provide the best thermal interface for heat transfer away from the LEDs. If I were to purchase a flat 1mm thick piece of copper, it would cost me more than the cost of the pipe, and I only need two circles of 22mm in diameter. As such, I decided to figure out how to work the pipe into an acceptable shape. To do that, I purchased an adjustable pipe cutter from Lowes to make a nice even circular cut.

However, you can see that the result of said cut is a jagged inside that also has a lip due to the malleability of copper. It needs to be removed. To do so I employed the same method that I used to make an even edge on all the other fittings I had just cleaned up: Tape even, file down until all the sharp edges and lip are removed, and clean up the edges using 400 grit sandpaper.

Once the removed piece had been cleaned up, I needed to turn a round piece of pipe into a flat surface. To do so, I followed the following steps:

1. Use a coping saw to cut the pipe straight down the side so I can unroll it.

2. Soften the pipe so I can work it into an acceptable flat shape, making sure not to damage the surface too much. In order to do so, I needed to overheat the copper with a torch, bringing it to the point where the copper was grey. Once the copper turns grey, you keep heating it up for a bit more and then expose the copper to water while hot. If this were steel, this would be a water quench, which would causes significant stress in the metal due to rapid cooling. However, copper reacts in the opposite way, it softens what had been hardened. I do not have any photos of the process as I was dealing with an open flame and did not want to risk myself or electronics when dealing with a very hot piece of metal. You can see my setup, with the propane torch pliers, flat hardwood surface, and bucket filled with water. Once the copper has lost most of its hardness, I bent it out somewhat flat with my fingers, then placed the roughly flattened copper between two sheets of wood and hammered it out to the desired flatness. The two pieces of wood prevent any direct hammer blows to the already soft metal, spreading the force evenly out over the entire piece, helping to create an even surface that isn’t scarred by the uneven force of an imperfect hammer blow.

3. Return the hardness to the copper so that it can maintain its shape to keep the pill in place. Copper is one of those metals that work hardens, meaning that any stress created while working the copper makes it stiffer and stiffer until you need to remove those stresses again by annealing as mentioned above. As such, it is quite easy to make hard again. However, as copper is such a malleable metal without that lattice structure, returning it to hardness without changing the piece you are working with requires a little bit of finesse. You basically hammer the copper (while still between the pieces of wood) hard enough that the force transfers through the copper, but not hard enough that you continue shaping it. When it is annealed too much, light hammer blows will spread the copper away from the force of impact, making for an uneven surface, so making it just soft enough to work in step 2 is just as important as the force and location of the hammer blows when you’re bringing it back to a hardened state. As you can see in the photo below, even between wood, there were evidence of uneven application of force in the copper. I revealed such unevenness by sanding the surface with an abrasive attached to a known flat surface. Everywhere that you can see oxidation is a location on the copper that is lower than the flat top surface.

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Nice to read about the softening and hardening of the copper. Maybe I’ll get hold of a decent torch before long. Just a little.butane pen torch I haven’t used in forever ATM.

Looking forward to seeing your progress

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Asian8640
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Now that I had a technique for working the copper, I could use it to solve the issue of not having copper pipe of the proper diameter to fit inside of the 3/4” pipe. The easiest way to determine how much pipe to cut away is with the simple formula Circumference = Pi*Diameter. We know that the difference in outer diameter between the pipe we have and the pipe we want is 2mm, therefore, the difference in circumference should be an additional 2*Pi for each concentric pipe I wanted. I measured out these lengths on my Calipers, marked them down on the sticky portion of a sticky note, and cut them out to use as markers on the pipe. As they’re sticky notes and don’t adhere to copper too well, I just held them down long enough to sharpie over them to provide a clear location where not to cut and then used a sharpie to mark a clear boundary box on the copper. It’s then as simple as cutting out the area between to the two black marks, filing the sides clean, and adjusting the fit by filing the opening.

In order to correctly shape the restricted tubes, I needed something to provide a point of reference, so I cut out a short length of copper tub and cleaned it up.


I repeated the process of annealing the copper and then pushed the roughly shaped copper inside the tube. I then used a wooden dowel to roll inside the tube pushing the copper into its proper place. I annealed the copper less this time, making it harder to work, but also making it easier to work harden back to where it was needed as I didn’t have a curved surface of proper hardness and diameter to hammer harden these rounded pieces. This process was repeated for the inner diameter piece by leaving the outside tube within the jig and repeating the process. There are three reasons the pill needed an inner and outer sleeve:

1. Two pieces of copper soldered together provide greater structural rigidity than just one.

2. The lip will be thicker, providing a greater surface area to hold onto the top of the pill when they are soldered together.

3. In order to hold the driver in the pill, it needs a place to go. The driver is 17 mm in diameter, so there needs to be a surface that has a minimum diameter of 16 mm and maximum diameter of 18mm to give the pill a shelf to sit on where it can be soldered to. It is easier to form that shelf when you can just move two separate pieces and ensure the inner surface is flat before soldering them together instead of dealing with creating a flat surface after the fact


Plumbing solder was used to adhere the structural pieces as it has a higher melting point than leaded solder, a feature that would become important later when attaching the electronics. To solder the bottom part of the pill together, I cleaned all surfaces with 220 grit sandpaper to expose the unoxidized copper, fluxed the surface with water soluble flux to prevent oxidation during the soldering process, and proceeded to evenly heat the piece from the bottom as heat flows upward, moving the torch around the bottom until the top reached soldering temperature. If the top is hot enough, the bottom is hot enough as the top will be at a lower temperature than the bottom as the bottom is constantly being exposed to direct flame while the top is just receiving heat through conduction.


At this point, I made an error in my decision making. As solder flows down, it would pool at the lowest point, meaning it would pool in the area created for the pill, obstructing the pill before it had even been placed. What I should have done was solder from the shelf down, as it wouldn’t matter that solder pooled at the interface between the body of the pill and DTP-PCB shelf. That was already slated to be cleaned up with a file anyway, and the solder being made primarily of a very soft metal makes it really easy to remove with a file.


The solution to my problem would come in the form of just following through with the next step, which was soldering the disparate pieces of the pill together. The round pill would be placed on top of the flat surfaces to give the greatest visibility and the excess solder would just flow down onto the fluxed piece below, both moving the excess solder from where it wasn’t wanted and attaching the disparate pieces. The flat shelf was not cut into a circle beforehand in order to better line up the pieces afterwards as they would be soldered together and could be worked as one piece.


The shelf was not just a single piece of copper as I found 1mm to be too thin for both structural and mass purposes. Due to my relative inexperience with hand tools, I knew that I’d be unable to provide good surface contact between the pill and body relative to a pill threaded into the body. It was a good starting point to just operate under the assumption that thermal transfer to any piece not soldered together did not have sufficient contact to provide heat conduction away from vulnerable parts. Since the pill was entirely soldered, I operated under the assumption that only the pill would be providing significant thermal sinking and provided it with as much mass as I deemed necessary. This idea is supported by the P60 format for lights, where such a non threaded pill that has been machined to much higher tolerances than my crude hand tool based approximation doesn’t have sufficient contact for proper heat conduction. The pill could not be soldered to the body once inserted as enough heat to melt the structural solder would definitely be enough heat to melt the solder on sensitive electronics, something I would feel acutely later on when attaching my driver to this pill.

The second layer of the shelf was created by cleaning both surfaces with 220 grit sandpaper, fluxing both surfaces, placing the incomplete pill on top of the second half of the shelf, heating them both to temp, and using capillary action with the flux to draw the hot solder across the boundaries between the plates.

Once all the disparate copper pieces were connected, it was time to round out the shelf. As the outer diameter of the shelf would be the same as the outer diameter of the body, I took the same piece of copper I had used to shape the round section of the pill, slid it over to provide a reference point, and marked out the area to be cut off with the purple sharpie I had on hand. Once that was done, I simply stuck it in a jig and rough cut the shape with a hacksaw and refined it with sandpaper/file.



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Nicely done! Thumbs Up Good fabrication techniques

Asian8640
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For this next part, I took a tiny detour. While I was having one of my walks through Lowes, I got a bit sidetracked. I saw something that I had missed: an adapter between 3/4” pipe and 1” pipe. This meant a piece with a lot of mass that I could use. I decided that, despite the fact the pill would sink most of the heat, adding more mass at the head wouldn’t hurt. I could cut in a few shallow fins, and maybe make it easier to make the head removeable as I had more depth for a countersunk screw head. This would work because I already had M2.5 × 0.45 screws left over from a previous build. Due to its mass, the adapter cost half of what an entire 2 foot piece of pipe cost me. I wanted to expand upon the shape by adding a narrower ring below the main head to increase the surface area in contact with the body to make up for the short length of the adapter compared to the slip fitting I originally intended to use, which I eventually ended up returning to any way. To do that, I purchased a high speed cutter for my dremel tool in order to hog out a portion of the adapter so I could slide half of a slip fitting into it. To make sure I cut out exactly what I needed, I put the pipe into the adapter, slipped a slip fitting over the pipe, carved the outside of the copper where the hogging should stop, and applied sharpie as a backup for easier visuals.

Cutting out this section took me about 7 hours over the course of three days using a method which Old Lumens called the Human Lathe method, constantly marking each section for each pass to get as even material removal as possible. Copper’s malleability was a huge problem due to inconsistent chip production as a result of it being so soft that the cutting bit could sometimes catch and just gouge out a greater portion than intended, or chatter as the cutting bit continually slipped, gouged out a small chip, and slipped again. I was constantly turning the piece in the vice, and working outside, as there was nowhere inside to deal with tiny pieces of copper flying everywhere. Eventually, after destroying a sanding drum finishing the inside, I managed to get the two pieces to fit in a satisfactory manner.

I slid them together and soldered the two pieces. SUCCESS! Or was it? When I first soldered them together, they didn’t fit perfectly and I could not slide the piece past the point where the joint formed. I tried sanding it smooth, but the problem wasn’t something that could be fixed by cleaning up the joint. As the section was made with hand tools that I had questionable control over, as nicely as the two pieces fit, it wasn’t straight enough. I needed to have something inside to hold it up, and the only thing that fit perfectly was the copper tube I intended to put it over, so after desoldering the joint and cleaning it up a bit, I stuck the copper pipe in to provide a guide to properly align the two pieces. This was a fatal mistake. When I resoldered the joint, despite the fact that I hadn’t cleaned the pipe and intentionally left it highly oxidized to prevent soldering, it must have gotten clean somewhere when fitting these three tightly fit pieces together because the three parts were now tightly connected. I tried for an entire weekend to remove the center piece from the two outer pieces, but either not provide enough heat or enough physical force to remove the copper pipe from the fittings. Eventually I gave up. I could have started again and purchased another piece, however, I came to the conclusion that it would have resulted in too much forward mass on the light as I had been test fitting the pieces that had not been stuck together and already found the light quite forward heavy. As such, this particular section of production came to an exhausting end. I cut the remaining pipe off so that I could use it for the rest of the build and continued onward.

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Now back to our regular show:
It turns out that wasn’t so careful when flattening out the surface of the round portion of the pill. As you can see in the picture below, the pill is tilted which means that the optics wouldn’t fit perfectly and would be leaning. That is unacceptable.

I decided to take it apart, clean everything and redo the joint.

Perfect!

At this point, I realized that I did not have everything I needed to finish the project, so I went and made an order at MTN electronics. I ordered a 20mm foward clicky switch pcb with spring, a 17mm 1A buck driver, and a whole bunch of M2.5×0.45 screws, which I had originally intended to use to hold the head and switch onto the body. I wanted a 20mm pcb thinking that it would be easier to attach the switch once the build was completed as the inner diameter of the copper tube was the same as the outer diameter of the pcbSince the original driver I wanted to use required a reverse clicky switch to properly function, I temporarily cannibalized my Convoy C8 for the reverse clicky switch. As you can see, although the forward clicky switch is much taller than the reverse clicky Omten 1288, their width is the same and thus can be swapped.

A quick dab of the soldering iron and now we have exactly what we need.

Now that I have the switch I needed, I needed to build the rear cap to hold the switch. The rubber boot commonly used on Convoy and many other flashlights has a switch dimension of 16mm diameter, a flared base diameter of 20mm, and a height of 8mm. As such, I needed a base with a 16mm opening with a 20mm tube. It was quite nice that it just so happened the 3/4” tube has an inner diameter of 20mm. I originally wanted to use the flat caps that would fit over the back and drill my way through. However, drills can and will slip, meaning that the hole I drilled would not be centered. The other problem would be that I did not own a drill bit of 16mm in diameter, and if I used a smaller drill, I’d have to file the edges to a perfect circle, something I demonstrated that I have been unable to do at the time. As such, I fell back on the method I used to construct my pill: necking down the copper pipe and soldering it together. I cut two really thin pieces of copper pipe, with the one slated for the outer diameter slightly taller than the one slated for the inner diameter so that I could more easily control where the solder would flow when hot.

Once soldered together, I filed down the high side until it met up with the low side.

I then took the piece of copper that I had been using to press fit the rings together and used it as the inner part of the main body for the switch housing. It had already been cut out with all corners smoothed over, as well as being a good height.

Finally, I cleaned and flattened the end with a file. However, I did not attach the final outer fitting as I had yet to determine exactly how the switch would fit together, not to mention the fact that I hadn’t cut the fitting to size in the first place.

I decided to take a little break from fabricating the end piece and switched over to working on the emitter and pill. While examining my pill, it was at this point where I switch from the single emitter to triple. My pill was the incorrect size for a 20mm single, being too narrow to make the holes at the edge as the maximum diameter that I could drill from center was 16mm. Also, if I had tried to modify the pcb, I was unsure of where the traces were and didn’t want to destroy a pcb by accidentally filing completely through the connection. I drilled a hole through the center of the pcb with my cast iron hand drill and then planed the top surface until it was flat, removing the deformation from the drilling as well as any deformation from the original hammering.

Now, I moved on to reflowing my emitters onto the copper PCB. This was a fairly simple process as the PCB was cooper dtp and would heat fairly evenly with any heat applied under it. I did not have the proper method for hot air rework, so I placed the body of the soldering iron onto the bottom of the pcb, applied ChipQuik 60/40 solder paste to all of the contacts, and waited for all the solder to melt. Once that happened, I quickly placed my three SST20 2700k 95+ CRI emitters and removed the heat source so I wouldn’t overheat the piece. It turned out quite well if I don’t say so myself.

After that tiny detour, I needed to find the correct sized spacer to fit my switch pcb into its housing. When looking at the Convoy driver, they don’t use a perfectly fit space, just one large enough to do the job. As such, I didn’t need to fabricate my own spacer, I just used a 3/8 stainless steel washer as the spacer for the switch. Below, you’ll see how this all initially fit together.




In that final photo above, you’ll see a significant gap between the top of the pcb and the top of the copper tube. In order to make sure the pcb wouldn’t move during use, I decided to cut a copper ring, out that would be soldered to both the pcb and the sidewall, ensuring a strong connection.

However, this would come at a significant cost. That tiny piece of copper was too much for my soldering iron to handle and it could not evenly heat the whole piece, meaning I would never be able to mount it straight unless the whole piece was up to temperature. For that, I used the propane torch that I had been using for fabrication… and destroyed everything but the pcb itself in the process.

The heat removed the temper from the spring and burned it, which made it useless, and the heat through the pcb melted the switch body.

Well, time for an unexpected new switch and new spring. I decided to order from Mohr Lumens this time, as they had already complete convoy PCB’s, which I needed to replace the cannibalized one from my C8, as well as a bunch of Omten 1288 switches in case I screwed up soldering on the new switch as the 1288 is quite fragile to heat plastic wise compared to other switches I’ve used.

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While waiting for the parts from MohrLumens, I thought it would be a good idea to finish the tail. I took a stopless fitting, cut off the section with lettering, and soldered the entire piece together with what I must say was my cleanest joint of the entire project.

The bottom wasn’t too clean, as that tiny bit of excess solder flowed out the bottom. At the same time, I finished the head of the light, soldering a ring in a fitting to create a stop where I could fit an O-ring. The O-ring would protect the 22mm x1.75mm UCLv3 lens (purchased from flashlightlens.com) from direct contact with the copper, ensuring a more even pressure distribution to prevent potential cracking during the event of a drop or accidental hard contact with another surface.


With a little bit of filing and edge sanding, it cleaned up fantastically!

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During this next part, I really didn’t document what happened due to frustration on my part. I was fighting tools for a week. All I have is two pictures of the final product with none of the testing and failures it took to get there. I had originally intended to use an M2.5×0.45 screw with tapered head. However, every single one of the tap and matching drill bit sets I ordered snapped within two turns, and I know that I was being quite gentle and even in the application of pressure. The drill bit itself was poorly shaped and would not bite, despite being quite sharp. The quality was just too low. I didn’t want to waste more money purchasing tools that broke. I could have purchased from McMaster-Carr but I didn’t feel like paying $30+$15shipping for a single tap set. I was testing the drilling and tapping of the copper on the failed piece of adapter from a previous step. If it wasn’t going to be useful as a part of the final product, it might as well be useful in testing things before applying them to the final product. I tried #10-32, but the threads were too coarse for just a mm of copper wall thickness and the head too large so that it would protrude out too much even when fully screwed in. I settled on #4-40 thread from Stanley purchased from Lowes. The screw would be similar enough to M2.5×0.45 that it wouldn’t be too much larger, and if the tap/drill bit broke, I could just easily acquire another one at a local store for $5 instead of waiting a week for a new set.

I then took a #4-40 3/8” pan head screw with a single slot and cut off most of the length of the threads until the screw was only 2mm tall from the bottom of the pan head. The pan head was 7/32” in diameter so it fit perfectly in the 7/32” hole drilled in the tail cap. When fitting the pieces I noticed an issue: The fit between the tail piece and body was slightly lose as the drill bit had drifted ever so slightly when drilling out the locking hole in the tail. To remedy that, I slipped another 22mm x 1mm o-ring between the body and tail cap to take up the 3/4 mm of empty space between where the body was supposed to stop and where it eventually ended up.

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The next set of photos is to show how I intended for the head to fit together. They were taken before the driver was attached, which is why you don’t see wires sticking up through the center yet.

1. Thermal paste the pcb to the pill after soldering the wires

2. Insert Carclo 10509 Floody frosted triple optics into the proper restraints on the PCB.

3. Insert the copper space that will center the optic, prevent it from moving, and transfer all the shock to the body of light if dropped, preventing damage to LED and PCB.

4. Insert the first 22mm O-Ring. The spacer should be just tall enough and tapered so that the glass is slightly above the optic, but lightly touching when pressed together

5. Place the 22mm x 1.75mm HCLv3 AR coated glass on top of the first O-Ring.

6. Place the second 22mm O-ring on top of the glass, sandwiching it and protecting it from damage.

7. The head slides over the entire stack and will be held on via adhesive, as I found that I could not be accurate enough with screw and thread to hold the head exactly where I want it. The adhesive used was Locktite 222 Threadlocker Purple, the weakest threadlocker available. Threadlocker was used in case I wanted to switch something out, or needed to repair anything in the head, so an adhesive strong enough to stand up to regular use but removable if necessary was needed for the project. I understand that there are no threads here, but it works fine. Threadlocker blue, your standard medium strength threadlocker, would have required too much force to remove in my experience.


Asian8640
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My order from Mohr Lumens arrived, allowing me to finally replace the destroyed spring and switch, although not without a minor issue of its own, where I accidentally destroyed yet another switch by heating up a contact for a second too long and melting components internally.

Now that I finally had a switch assembly again, I needed to attach it to the tail cap via solder. This turned out to be quite a problem, as I did not have a soldering iron large enough to heat up both the pre-tinned inside walls of the tail cap and the copper ring. I couldn’t use a butane torch, as the rubber tail cap would have burned if the entire piece was brought up to soldering temperature, not to mention the potential destruction of the fragile Omten 1288 switch. I did have my grandfather’s 140W Weller soldering iron, but after searching fruitlessly for three days, it could not be found. If you look at the solder joints in the photo below, you’ll see that I eventually settled on a substandard solution to the problem, as I really didn’t want to spend money on a soldering iron that I already owned and was probably lower quality. I used the fact that leaded solder melted at a lower temperature, allowing for a slightly longer working period, to use my lower powered 30W soldering iron to slowly feed bits of solder, one small joint at a time, into the interface between the ring on the switch pcb and the body of the tail. It’s not clean, it’s not good looking, but the solder joints aren’t cold and it provides the necessary mechanical and electrical contact required for functionality. I might clean it up when I eventually find my grandfather’s soldering iron, but this is the way it will stay for now.

Attaching the driver to copper pill while providing both electrical contact and a thermal conduit via solder proved to be my final major problem. In order to do so, I needed to bring the entire piece up to temperature so that all the solder in the driver shelf would melt, allowing me to solder the driver to the pill. However, my first mistake was positioning the driver on the shelf while I heated up the piece. Due to the fact that I had been using a large propane torch, the lack of airflow meant that the entire chamber formed by the driver covering the opening to the pill heated up to temperature, melting the solder on the driver, causing parts to fall of. I destroyed my original driver this way, as well as accidentally burned a second one from my previously cannibalized C8 when I was lax and moved the flame too high. Another issue with using such a large torch was that the entire piece got hot enough to melt solder, meaning the bond holding the round portion of the pill to the shelf became liquid as well, and trying to adjust the driver moved everything out of alignment.

It was a good thing I had purchased that 1A buck driver as a backup in case I destroyed my original driver, as I had already burnt through two drivers. The solution to my problem came in two parts:

1. I would heat the driver shelf up with the driver above the pill, held in place by the silicone wires used to connect it to the triple LED pcb, pre tin the contact on the inside of the driver, and push the driver down into the liquid solder on the pill shelf, with the sheer mass of the pill providing the required heat retention to keep the solder in a liquid state long enough to perform this action.

2. I required a heat source that provided a much more focused source of heat so that only the driver shelf would be liquid, not the solder holding the pill to the pcb shelf. That came in the form of purchasing a smaller Ronson butane torch with pin focused nozzle.

Once the driver was connected, I easily soldered the connecting wires onto the triple PCB, applied Noctua NT-H1 thermal paste to provide good thermal transfer between the pcb and pill shelf, and stuck the pcb to the pill.


After this, it was just following the pre-determined assembly steps and taking the final photos.

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Amazing work mate.

Asian8640
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everydaysurvivalgear wrote:
Amazing work mate.

Thank You. It means quite a bit to me coming from you.
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That took some great patience and talent. Thumbs Up

Asian8640
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Well, we’ve reached the end here. Here it is! The finished product.



And a beamshot! It was taken about 8 feet away from the wall.

Here are a few tidbits about this project I’d like to point out now that we’re on the final build post.

  • I started this project on October 3rd, and I completed it on November 23rd.
  • All the self-manufactured parts that ended up in the final project were made completely using manual, non electrical hand tools, the only exception being my soldering iron as I am not in possession of a butane powered soldering iron and didn’t want to spend on one.
*Although I didn’t show it, every single piece had to be filed down evenly and all edges removed with sandpaper due to that annoying lip caused by the copper pipe cutter. That is what took the majority of the time. More preparation now means not having to do everything over later.
  • I needed to refurbish the manual hand drill from my Grandfather. The handle no longer stuck on from years of use and the wood had cracked. It would have been fun to see, but I was more focused on getting a nice round handle without a lathe.

Here’s a quick question and answer section to cover things that you guys may be thinking of.

Q: Why didn’t you clear coat the copper? Now it’s going to oxidize and won’t have that brushed finish for long.

A: As of the completion of this project, it is too cold outside to apply spray clear coat and have it dry evenly. I normally do all my spray painting outside so there are no fumes in the house as I am quite sensitive to the odor of spray paints wafting up through the rest of the house. If I did it in the basement, it would still be too cold as the basement isn’t heated and, although it wouldn’t freeze, the smell would still be able to permeate the house via the duct in the furnace. If I want to do this in the future, I’d have to wait until the weather warms up.

Q: Why didn’t you make the tail cap a twist lock system? Wouldn’t it have been easier to take on and off to get at the battery when you need to recharge it? 1A, while not that much by enthusiast standards, still draws quite a bit. You’re bound to only get around a 3.5 hour runtime anyway.

A: I wouldn’t trust a twist lock system to hold up to regular use. Keep in mind, copper is both malleable and ductile. Every time I take it on and off, if there was only a bit of copper, say 1cm holding the locking pin in place, that is a moment where the force of the pin acting on the body creates a weak point. Yes, there are issues such as getting such a small screw back in and out every time I want to swap the battery. It is a royal pain. There are also issues of the same screw and all the forces working on such a small threaded piece, but the upside of it being a screw makes it less likely to come lose and fall out during normal use compared to a twist lock system, making this less than ideal solution a failing I am willing to put up with.

Q: Why did you use a wide spot frosted optic instead of a more general purpose narrow spot frosted optic?

A: The wide spot frosted looked better, as it looked a little less green. Also, it’s a single mode light meant for close range, I don’t really need longer range with it. I have other lights for that. This is for high CRI, low CCT, evenly dispersed light.

Q: Why didn’t you buy a tap and die to thread the flashlight?

A: A tap and die set large enough for this project with threads fine enough to work on pipes with only 1mm wall thickness don’t seem to exist, and if it did, would probably be prohibitively expensive.

Q: Why didn’t you solder on any heat fins?

A: I don’t think I would have been able to make it look good. I got some good joints, but my application was quite uneven when dealing with such large pieces. It only looks halfway decent because of the cleanup. Also, those extra fins would have added weight at the head, making it more head heavy than I would have preferred.

Q: Why didn’t you extend the tail to make it tail stand and have protection over the button?

A: I thought of that, and did want to do that at one point. However, I would not have been able to clean up wherever the solder had flowed to as I would have had to file down wherever the excess solder had pooled. I would need to solder vertically so that the copper wouldn’t unevenly pool on one side, and due to the thickness of the structural solder I was using, the ability to control small amounts of solder was lessened. Leaving that one side open makes cleanup of the mess easier to fix in a cleaner manner.

Q: Why didn’t you cut a grip section into the body?
A: The 1mm wall thickness of the body made it about as thin as I was willing to have the body of the flashlight. Cutting into an already thin piece of material was unacceptable.

Q: Then why not solder on pieces?
A: It would have ruined the simpler clean aesthetic I was going for, and I didn’t think I’d be able to do so without affecting nearby pieces, therefore making it lots of effort for a sub-par finish.

Q:Why didn’t you polish it? Everything looks better when shiny.

A: I needed a rougher surface so that the Locktite would properly adhere and prevent my head from just falling off one day. Also, it’s partially there to hide imperfections in the copper pipe itself that, if I went after them with sandpaper and a file, would make the walls too thin. The copper pipe was the best looking copper pipe I could find, but even the best copper pipe wasn’t stored like it was going to be used for an art project. There were dings, dents, and scratches all over the piece, no matter which one I chose. I did my best to make it look good while minimizing structural losses.

Some final statements

I would like to thank Old Lumens for starting this contest all those years ago, and for the content he posted from which I have learned much.
I would like to thank CRX for being an inspiration with all his absolutely gorgeous hand made lights, to which I worked hard to emulate this year.
I would like to thank MtnDon and everydaysurvivalgear for their organizing of this year’s contest, taking their time and significant effort in bringing us all together once more.

Finally, I would like to thank all the participants for participating. Reading all your build threads, watching as things come together, and reading your thoughts on how everything has been going is always a joy. Without the contestants, there is no contest.

MtnDon
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I like the nice clean, but not super shiny appearance. Clean, slim design. Looks very good.

I have a de-burring tool to help cut away that annoying, inside rolled over edge that is left behind after using the tubing cutter. It is a hardened steel “hook” with an edge that cuts as the tool is moved…. hard to describe. It is built into my cutter. If memory serves me, it is made by Klein. Then I use a very fine oval shaped file inside the tube.