My rule has always been, if you wouldn’t put your willy there while it’s running, don’t stick your fingers there while it has power (plugged in and/or battery still installed)
Push stick story. A fellow I knew retired from the local lumber company. Worked there his whole life. He had made push sticks and gave them out to good customers and friends he had made over the years. They were about 3/8” wide and made out of mahogany. Poor choice of wood. When that stick touched the blade it literally exploded. Luckily none of it hit my face.
I’ve made a change in the overall design and constriction. I will use the 18650 cell but mount it inside the main body rather than in the finger-jointed box I made earlier. That box will get used for something else, maybe it will simply be a decorative box?
I cut grooves in the lower end of the two side plates of the body. I used a 3/4” straight cut router bit and cut a recess about 5/32” in depth on each side.
The base of the light will now be a simple plate instead of a box. I cut some more of the wenge to make the base plate. I am using two #6 x 3/4” flathead stainless steel screws to secure the plate to the sides. The drill press was used to bore the holes and to make the countersinks. Wenge is far too hard to even accept wood screws without drilling a pilot hole as well as a clearance hole. Later I may also glue the base to the body.
The space below the padauk window frame will be filled in with a piece of wenge. This will come later.
The finger joints are snug enough to permit handling but I also have rubber bands in place as extra insurance against having it come apart and pieces fall to the floor.
The LED circuit board needs some trimming. It is both too wide and too tall.
I needed to trim the width by approximately one row of holes, so I simply used the bench belt sander to remove that material. The length needed more trimming and I used a fine tooth Xacto saw for that, then finished with a touch to the sanding belt. I may need to trim a little more off the upper end but will wait until all the other case parts are done.
Here’s the view from the backside. The board slips in nicely.
Sooner or later I was going to have to get to the electronics portion of this light and that time is now. There will be a Nanjg 4*7135 driver and a TP5000 based charger. These will produce some heat in use and as the wood itself is a better insulator that a radiator I will be incorporating a metal heat sink.
First, the driver mount. This will be a copper ring; a section cut from a 19mm OD copper tube. With the 1mm walls that leaves just enough space inside to secure the 17mm driver.
Now we take a side step. The heat sink with driver and charger board will be mounted to the back plate of the light. But I haven’t yet made the back plate. So that is the next thing.
I cut some thin strips of wenge to use to make a back. I have no wenge stock left that is wide enough, so must glue up a couple of pieces. I decided that to dress up the appearance a little I would incorporate a narrow strip of the padauk down the center. The padauk was cut to be a little thicker than the wenge as padauk is softer and sands easier/faster.
After the glue has set…
Sanded…
Here is the heat sink material. I believe it was made to assist cooling either a SSD or a stick of RAM. It is placed about where I plan to have it on the outside of the back plate.
I jigged up some stop blocks on my router table.
This is to make cutting a recess out of the back plate that the heat sink will fit into. Many trial settings were done using a scrap of pine. Once the stops were positioned properly for the length they were solidly clamped to the table. More trials were made to position the fence correctly for the width. Spacer blocks (narrow black things inset between the wood stop blocks and the fence) allowed the width of the recess to be made to fit.
The heat sink will be more or less flush with the back surface and have the driver and charger mounts protrude into the interior of the light body.
A chisel was used to square up the corners. I thought of rounding the corners of the copper heat sink, but chose to square up the wood corners.
…more from today in the next post…
Back to the heat sink driver mount…
I sanded a small flat to one side of the ring mount and silver soldered the joint…
A small angle piece of copper was soldered in place to serve as the mount for the charger…
A slot was cut out in the recess. Holes were drilled first and then the waste was removed with a chisel to form the opening…
The driver and charger were trial fitted; just sitting there balanced in place. The slot was elongated to one end…
That is about it for now. Thanks for stopping by.
Looking pretty trick! And I can’t recall the last time I saw anything Brink & Cotton…neat!
I have a boxful, a dozen I think, that must be about 30 years old. Other than a few missing plastic tips and the odd weld mark they are still great.
As built the back plate ended up being a little thicker than I wanted. I do not have a thickness planer so I elected to re-saw it from the inside surface, then re-sand that face. The thinner back makes for better interior clearances.
Here is the back with the heat sink assembly fitted…
A chisel was once again used to square up some corners, this time in the body where the back plate is mounted.
Now back to the front side. That gap under the window frame needs a filler piece. I cut some more wenge…
The perf board needed some support to provide its final setback from the padauk window frame. Some thin pieces of wenge were cut and glued inside the body.
On the left of the next shot, which is the top of the body, a narrow strip can be seen added to the interior. To the right in the image, near the lower end of the body are two strips, one on each side.
The perf board sits against the strips…
This seemed like a good time to finish off the body. In preparation for gluing the corners I cut off the exposed finger tips.
I used a small Japanese made, very fine toothed pull saw. The teeth have no set to them. The blade is 0.012” (0.3mm) thick and very flexible. Even though the teeth have no set I use a strip of masking tape as protection just because I want to. After cutting and gluing the fingers the corners were sanded smooth using the bench belt sander. I used CA glue and accelerator.
FYI, the teeth on one side of the saw blade are designed for cross-cutting softwoods, the other side with the smaller, more closely spaced teeth are for cross-cutting hardwoods.
At this point, there were a few glue line imperfections. These were filled with medium-thick CA and hit with the accelerator. Sanding with a 240-grit belt cleaned up the remnants of glue here and there.
…These pieces are ready for further work…
That does it for today. Thanks for checking in.
A reverse clicky switch will be used. It could be mounted in the top to be in a convenient easy to use position. Or a side. I had planned to place it in the upper surface of the battery box I was originally thinking of using. I have decided to place the switch in the back plate, near the top. That way the light has a cleaner appearance from the front side and should still be easy to operate.
Two switches are pictured, both Omten 1288 types. Only 1 will be used but so far I am unsure of with bent tabs or not. Probably bent tabs…
I first drilled the 1/2” hole part way into the back from the inside. This is to fit the outer rim on the silicone switch boot. The inner hole was drilled with a 5/16” bit.
An additional block of wenge was used to make the switch body holder. That is a 15mm hole, drilled through the wenge.
That block will be glued as shown below. The switch with bent tabs will be pressed inside the 15mm hole. The ‘nub’ inside the silicone boot had to be shortened a bit to allow for proper switch operation, btw.
A groove was cut and chiseled out to provide passage for the switch wires. The lighter colored striped wood is bocote. That is a cover plate that will secure the switch in its mount.
Wires were soldered to the switch tabs. A small piece of redwood was cut to be a spacer block between the back of the switch and the bocote retainer strip.
Here’s a view of the rear of the body with the rear cover plate fitted.
That was one of the more complicated switch mounts I have devised for my scratch-made lights.
A back plate would usually be secured to the body with 2 or even 4 screws. I wanted to use as little visible hardware as possible. So the next step was to make a one screw system work.
After a bit of trial and error, I cut and sanded a small piece of hard maple. In conjunction with a small finger of wenge, this will make a catch for the upper end of the back plate.
With the maple strip and the finger of wenge both glued in place, the top end of the back plate is held in place as the back is inserted and slid upwards. There will be a single screw located near the lower end of the back.
Thanks for looking. That’s all for tonight.
That is a lot of work and thanks for sharing your detailed progress, Sir 
It looks very nice and professional level.
Don’t forget to test the circuit during each step 
With the upper locking assembly completed the next step is to make what is needed to use a screw to secure the back plate to the body. I use whatever scraps and cut-off pieces I have wherever I can. So here I used a larger block and a thinner strip to glue up a spacer block. Once again I used a couple of drops of medium-thick CA plus the accelerator.
With those glued together that assembly was glued to the body.
With that block assembly glued together another thin strip of wenge was sanded to just fit between those blocks and the back plate with minimal clearance. That strip was CA glued to the inside face of the back plate, positioned to be aligned with the block that was glued into the body. This is to reinforce the three glued up back pieces across the padauk glue joint. I intend to drill a hole through the back plate at the narrow band of padauk. It seemed wise to reinforce that.
Here’s the screw hole being drilled.
The hole was countersink for the flat head screw. It is a regular S/S wood screw. A pilot hole was drilled in the block n the body to make insertion of the screw easier and less likely to split the hard wenge.
The next step was to make a slot for the USB-C charger port. Two 3/32” holes were drilled and a chisel, a carving knife, and a small round file were used to enlarge the slot.
I’m holding the port in place in its mounted position for a trial fit. Looks okay to me.
I soldered the driver inside the copper mounting ring. That secures it and completes the circuit from the negative outer ring on the driver to the copper heat-sink unit.
The charger board is TP5000 based. It is a 1 amp version. I affixed the board to the heat-sink tab with a small bead of Arctic Silver epoxy. I have a half tube left and it still works well. I keep it refrigerated.
Then I tested the charger once again just to be certain it worked. I had also tested the driver after soldering it into the mounting ring.
Here are two images showing the assembled heat-sink with the driver, charger, USB port and wires attached.
The next photo shows the trial fit of the heat-sink assembly with the USB-C port connecting wires soldered. The bi-color charge indicator led will be fitted into a 3mm hole I drilled in the back plate. After the wood parts are all clear coated the electronics will be installed and the final wiring done at that time.
Next the wood parts need to be clear coated…
Very nice build, (as always :) ).
I would add some extra isolation between the positive tab and the cell since the tab is usually sharp and this shrink wrap is very thin.
That is a good idea YuvalS. Thank you.
After a light sanding with 320 grit paper the wood surfaces had a water based clear finish applied. The finish I used is made by Varathane. It is an exterior finish, chosen because it has UV inhibitors. These exotic woods usually darken after a while when exposed to UV light. They also usually darken when exposed to air; oxygen is the culprit. A good clear coat with UV inhibitors drastically slows or stops the darkening. This wenge is different. It can get lighter when exposed to oxygen and UV. This finish is only available in a brush on. Most clear coats do not have the UV inhibitors.
For the final coats I prefer a spray finish as that eliminates any chance of brush marks. I prefer lacquer as it dries fast and does not require sanding between applications.
The clear coat does deepen the colors of the woods a little. Five thin spray coats were applied. Lacquer dries for a re-coat in 30 minutes or less; more like 15 to 20 minutes with the generally low humidity where I am. It is best to let it sit for a day before handling very much.
Time to begin the final assembly. First up is the heat-sink unit. I cut some narrow strips of double sided heat resistant tape.
The heat-sink unit was pressed in place. In the past I have somehow managed to mix up the connections for the bi-color indicator led’s. That is a real pain to unsolder and re-do. This time since I have room to add a perf board pin header P did so in order to use plugin connections. The next image shows a three pin strip ready to be soldered to the charger board. The white wire had a terminal on each end; one to fit one of these pins and the other to connect to a leg of the bi-color led.
Here are the three connector wires hooked up. The led is about to be glued in place. It tests as being wired correctly. The USB-C port was also glued to the back plate.
Next the padauk window frame was fitted with a small piece of the Warlon Washi Shoji paper. It is a remnant from a previous project. It is made in Japan for use in Shoji screens. The paper is laminated with a thin plastic sheet for durability. It is affixed to the shoji frames with a thin double sided tape that has excellent grip.
The tape is 5mm wide. There are a couple of varieties for thinner and thicker papers. The instructions are quite detailed.
Here I have started the installation of the shoji material. After sticking the main strips to the window frame I trimmed the width with an X-Acto knife. The center strips of adhesive tape were trimmed before installation. The paper has been started by stripping off the protective layer of the single end piece of tape. Then the paper was aligned and pressed in place. It has been rolled back to expose the other tape pieces which still have the protective covering in place. If this was a larger frame I would also apply tape to the horizontal center rail.
…With the shoji paper held back the covering was removed from the tape…
The paper was firmly pressed into the tape and this is what it looks like from the front side…
On to the PCB board. It fits inside the box with very little slop. I cut two thin strips of scrap maple to act as retainers for the pcb. I used more of the double sided heat-sink tape to adhere the maple to the sides of the box. If I need to remove the pcb for some reason the maple strips can be pried off using a thin blade. I did not use the shoji tape as it is very difficult to pull loose.
On a suggestion by BLF member YuvalS I added some tape to the ends of the cell to help protect against the tabs cutting through the cell wrapper. I used kapton tape. I soldered needed wires to the tabs on the 18650 Samsung 35E cell…
Here everything is wired up and ready for the back plate to be installed…
The window frame is to be secured to the body of this light with two small pieces of the heat-sink double-stick tape. Test have shown me that this tape will come loose before the shoji tape in case I need to remove the window frame. However, it grabs enough to prevent falling apart on its own.
Several images of the completed and assembled light will be posted soon
Here are five images of the completed light.
Front 3/4 view with 18650 cell for scale.
Lamp only
Lamp turned on with low brightness setting
Rear view
Rear view with USB cord plugged in. Red = charging.
And finally, here is a video clip…
(It appears at the end of this video that Youtube automatically advances to one of the video clips of the logging feller/buncher machine.)
It’s amazing that so much work goes into something with such simple and elegant lines. Well done Don, as usual. Another beautiful light!
She’s pretty. Once again nice work.
Beautiful light. Great job.