[FINISHED]MtnDon's 12th Annual BLF Old Lumens Challenge Entry - Hand Made Category

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Well, here we go again. I have gathered some parts and materials and have a rough mental plan.

Some of these were on hand; the 10 inch piece of 1 “x 1.5” aluminum tube is a leftover. So are the pieces of copper tube and strap stock. The driver, mcpcb, optic and charger circuit board were waiting in little boxes, looking for something to do. I did order the 2000 mAh Vapcell 16650 cell from illumn.com. This one tested out at 2128 mAh. Some 519A LEDs are on order.

I call this my proof of interest image.

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The 12th Annual Old Lumens Challenge - 2024 - Winners announced!
The 12th Annual Old Lumens Challenge - 2024 - Winners announced!
The 12th Annual Old Lumens Challenge - 2024 - Winners announced!
The 12th Annual Old Lumens Challenge - 2024 - Winners announced!
The 12th Old-Lumens challenge - 2024 - People's Choice Award - Choose your favorite!
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Looks interesting to me MtnDon!

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It’s always fun to follow along with your builds Don. :+1: I usually learn something too.

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I believe it is your first ever “metal only” build :slight_smile:
Good luck!

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You noticed! :+1: Yes, I thought I would try not using any visible wood components.

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I’m looking forward to this. I think 16650 format lights are underappreciated. I have yet to get one, but I think it would help the pocket-ability over 18650 lights.

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I did a little work on this today. Not much, but a start.

I cut the aluminum tube and a strip of the 1/8" x 3/4" copper to a size closer to the final size. It is still longer than necessary but easier to handle. I used my miter saw with a negative 5 degree hook carbide tooth blade.

The aluminum tube is 1/8" wall and 1" x 1.5" OD; with the ID working out to 0.75" x 1.25". The copper is sold as 0.75" x 0.125". Production tolerances have the aluminum ID width as not quite 0.75" and the copper as slightly over 0.75". The copper strip won’t slip into place.

So, a few passes of the copper strip on the 220 grit sander belt was needed. (the image is staged with the machine turned off for ease of operating the camera safely)

The copper strip now fits into the aluminum tube. It can be slid back and forth and will fit snugly against the inside of the aluminum.


The blue is the reflection of the sky through the open door behind me.

That’s all for now. Thanks for looking.

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So just when I was thinking of getting back to the workshop and working on this I had a kitchen mishap.

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I had a small but very sharp paring knife slip. Stupid thing. Not only did I get blood all over the cabbage but I have 4 stitches in my thumb. Plus, because of the location of the cut, a finger splint to immobilize the thumb. That thumb gets used a lot and the splint is very much in the way. It’ll slow me down a bit but not stop me.

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Sounds incredibly painful there! What happened exactly? Just a slip or mishap? Hopefully you are ok, get better soon and good luck if you choose to keep working on your project.

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Ouch! When i saw the pic i thought you might’ve had the mishap in the garage. If it was a nice clean cut (sharp knife as you say) hopefully it’ll seal up and heal quickly

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The doctor said it was a nice clean cut. It was a thin narrow blade, about 4" and I was coring a cabbage head. The cabbage head was wet, rolled, my grip slipped and the knife cut through the cabbage surface and into my thumb. It bled pretty good while I rinsed it before binding the thumb. That was last night. This AM it was still seeping blood so I thought it might need stitches.

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Sorry to hear MtnDon. I hope you get better soon!

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I discarded the splint and wrapped the stitched area with a fabric Band-Aid and got to work on making some components for this light.

So the plan is to make a carrier from copper strap material for the cell, the driver, and the mcpcb to be mounted to. This carrier will then slide inside the rectangular aluminum tube.

The width of the main copper strip of the carrier has been sanded to fit the tube. A vertical strip of copper is to be silver soldered to one end of the longer horizontal main section. Today’s first image shows the two copper pieces clamped into position. The small wood block is to hold the short piece at a 90 degree angle to the longer strip. I have not used this method before, so we’ll see how it works. The wood block will likely char but not actually catch fire. I hope. The joint has had silver solder paste flux applied. Two small pieces of silver solder have been cut and placed in the flux at the juncture of the two copper pieces. A butane torch was used to heat the work.

The next image shows the work after soldering. The two little blobs of solder did not want to spread evenly so I added some silver solder from the roll of solder wire. The torch heat did scorch the pine block a bit but it never smoked, let alone catch fire.

Next is a view of the copper work with the clamps and wood block removed. The solder wicked between the two copper pieces to make a nice solid joint.

My aluminum right angle gauge confirms that the two pieces have been joined at 90 degrees as was planned.

The short piece of copper was a scrap. It was a little too long. Rather than try to hold and cut it by itself I elected to trim it after being soldered to the longer piece. I used my combination disc and belt sander. Now the carrier slides in and out of the rectangular aluminum tube easily.

I cleaned up the front end of the copper carrier by filing away some of the excess solder. There are a couple of soldering steps yet to come. When all is competed the heat marks on the copper will be cleaned away.

That is all for today. Thanks for having a look.

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A short update…

I am using a Sofirn SP10Pro driver for this light. Why? Well, I have a couple on hand and they have Anduril2 already flashed to the chip, and I like Anduril2. Plus they are small which suits the 16650 cell. They also supply enough current to make sufficient lumens for the purpose of this light. There is one inconvenient factor though. The 16650 cell was only available as a flat-top. The SP10Pro driver was designed for using a button top cell.

I could add a solder blob to the cell. Or I could modify the driver. The driver has two spacers on the face that faces the cell to prevent incorrect insertion of a cell from destroying the driver. I don’t like solder blobs so I chose to live dangerously. I removed the two “safety” bars. Then I added a button to the positive terminal on the driver. I suppose I could have tried to add the button to the cell but I was concerned about the soldering heat. Choices need to be made.

The next image shows a stock driver and the modified driver.

The black wire is soldered to the negative ring for test purposes only.

To ensure that the driver mods did not cause a fault I tested the driver with an old emitter on a mcpcb.

The driver still works; always good news after diddling with anything electronic.

That is all for now. Thanks for looking.

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Next on the agenda was to make a mount for the driver. The driver OD is a little over 17mm. It is a two board “tee” shape with the momentary contact e-switch on the non-round board. The switch will be used and will require some special parts.

The mount is made from two short lengths of round copper tubing. One is 19mm OD with 1mm wall thickness. The other piece is 17mm OD with 1mm wall. The 17mm OD will slip into the 19mm OD. Mathematics indicates the 17mm should slide into the 19mm OD tube. The real world says some fiddling is necessary. In part this is due to the rolled edge the tubing cutter makes. Production tolerances are another factor.

I removed the rolled edge on the 19mm tube by using an Exacto knife to carve away the rolled in edge. Then I sanded the ID of that 19mm tube. The 17MM OD tube still did not want to allow insertion so the OD of the 17mm tube was sanded also.

The perimeter of the round board part of the driver was also sanded down to reduce its OD and allow the driver to be fitted inside the 19mm tube. Eventually the driver will be soldered inside a short length of the 19mm OD copper tube. A section of the 17mm copper tube will be slipped inside the 19mm tube as a part of the mounting system. Photos will illustrate.

The 19mm OD tube being sanded internally…

The 17mm OD tube being sanded externally…

The 17mm OD tube now slides inside the 19mm OD tube

Driver sanding to reduce the diameter

Look carefully… the driver fits nicely inside the 19mm OD tube.

I thought I had a full 4 inch length of the 17mm OD copper tube, but was mistaken. I have enough to do the present task. However, I ordered another couple of pieces as I likely won’t have enough to make another part for the battery tube.

Both of these 17mm and 19mm tube sections are too long for the finished mount. I need to cut them and I prefer to use a tubing cutter over any kind of hand saw. The problem was that cutting very short lengths of tubing off an already short piece is difficult to handle. It is difficult to impossible to get a good enough grasp of the tube to rotate in in the cutter. I came up with a solution I think will work. Next time we’ll see how that goes.

Thanks for dropping by.

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OK. How to cut the short lengths with a tubing cutter? Sometimes in my OCD desire to not waste materials I must admit that I make tasks more difficult for myself. I gave this a little thought and came up with a couple of ideas. I decided on one and proceeded.

I found a drill bit that was a snug enough fit inside the 17mm tube that it gripped the tube and allowed me to rotate the tube in the cutter.

I was able to turn the copper tube in the cutter if I very slowly adjusted the cutting depth a very small amount at a time. I cut almost through the tubing. I didn’t want to damage the cutting wheel on the hardened drill steel. I used pliers to twist the tube off the drill and the twisting torque separated the two pieces at the cut line.

(another thought was to insert a tight fitting piece of dowel inside the copper tube and use that to turn the tube. But I didn’t have ant dowel on hand that was a close enough fit.)

With the two short lengths of 17mm and 19mm copper tube at hand I assembled the driver mount. The 17mm was slipped inside the 19MM. I used a wood dowel as a drift to slide the 17mm piece to the proper position. The assembled pair was then silver soldered to the carrier. Lots of clamps were employed to prevent anything from falling apart as the work was heated. I used a pair of butane torches to speed the job.

After cleaning up the carrier a bit this is what it looks like.

Here’s an explanation of how the copper tube mounts the driver. The 19mm OD tube section is 17mm long. The 17mm OD tube section is 8mm long. Look at the photo below; the 17mm tube is pressed inside the 19mm tube. One red arrow points to the ledge formed by the 17mm tube inside the 19mm tube. The other red arrow points to a step in the side of the driver tab that is fixed to the round part of the driver. The step fits against the ledge when the driver is inserted into the 19mm tube. Two small blobs of solder will be used to secure the negative ring of the driver to the 19mm copper tube.

The driver will be secured with the e-switch mount located horizontally. A pilot hole has been drilled in the side of the 19mm tube. The hole aligns with the switch button and will allow actuation of the switch via a push-rod through the hole. The driver will be secured to the mount with two solder bridges from copper mount to he driver negative ring.

I decided it was about time to flow the 3500K 519A emitters onto the triple MCPCB. I used my MHP30 mini hot plate.

After the reflow I once again checked the operation of the driver and MCPCB together. They work.

A wood (maple) spacer was made from a scrap. This will mount on the upper surface of the driver mount to hold and guide the switch actuator pushrod. I marked the position of the hole on the maple block with a short piece of pencil lead.

Then I drilled through the wood block and copper sleeve with the pilot drill bit…

Next I enlarged the holes using a 9/64 bit and trial fitted a piece of 1/8” dowel as a pushrod.

Thanks for looking. That is all for today.

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17

Excellent work, congrats !

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Looks amazing so far. I like the job you did soldering all the copper pieces together. The mount for the driver also seems extremely well-made. Was it time consuming to do all that by hand? The sanding especially seems tedious?

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Yes, the manual sanding can br tedious but it has to be done. Wrapping the OD with a small piece and rotating and sliding back n forth works pretty good. Same for rolling a cylinder of sandpaper and sanding the ID.

The soldering takes a lot of heat especially with all the clamps acting as heat sinks. And silver solder melts at something like 1200 F (650 C). I use that for the structural connections so I don’t have any concerns when I solder anything later using regular electrical solders.

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Looking really good MtnDon! :+1: