Inspired by DBSAR, my SRK-based Lantern

OK, today’s post is a teaser of sorts. I won’t be able to concentrate on working on this project for a few weeks. I took a detour from working on my BLF/OL 5th Annual Contest entry today because I couldn’t wait. I found some jars online that I thought could be used to complete this version of DBSAR’s SRK lantern. They arrived in today’s post.

A cheap SRK clone.

Three pictures… The first is me hacksawing some off the nose of the head using a split/drilled wood block set to hold the head.

Then one of the PET jars I found sitting in the nose of the head alongside the cut off piece.

And the body with the jar and a remote phosphor just like in last years contest entry

There will be more as I can get back to this.

Orsm Don. Looking forward to see this one proceed. Now get back to the OL comp build. :slight_smile:

Two months and 5 days after the start, I finished this. Not that I was working constantly on this; mostly it sat as I waited for a few parts and was occupied with other things. Today I took time to get it done. I must say I’m relatively happy, but also have my name in for two of the BLF Ultimate Lantern Project lamps.

EDIT: Since the photos were taken I shortened the coupling nut used for the top ring. I could have used one of the available ready made adapters made for tripod threads, but I didn’t want to spend the money when I could make something similar from materials on hand. 12/19/2017

I used yet another of the XT-E royal blue led’s and a remote phosphor. The phosphor has a color temperature of 3000 K.

The top is a PET plastic jar found on ebay.

A few “lamp on - lights out” shots at different levels. The driver uses 2 x 7135, 350 mA regulators. For the intended use I believe that is plenty of light and ensures a long run time with 4 x 3000 mAh cells. Even more when I get some 3400 mAh button tops.

Next will be some component shots.

Some of the head parts.

1/4” thick aluminum from the $4 a pound scrap bin at the local metal seller. It was laser cut for some project… I drilled the hole.

A copper plate with a piece of copper bar and a brass nut soldered on. The bar is drilled through to provide space for the screw to tighten without bottoming out against the copper plate. This fits in the forward part of the head where the mcpcb used to sit. The TP5000, 2 amp charger board is secured to the other side with arctic alumina. The ones I have came with a small finned aluminum heat sink glued to the underside of the board. I filed off the fins and glued the flat remant to the copper plate. That provides spacing away from the copper for the electrical connections to clear. But to be certain I also insulated the copper plate with kapton tape.

Plate fitted inside head

Jar trial fitted using a center bolt; 6-32.

The aluminum plate to be mounted for double duty as a heat sink and a mounting point for a hanger.

More pictures coming….

Very nice Don. Looking forward to the update with the charging port. :slight_smile:
How does one drill holes in jars?

I filed out a recess for the micro usb port for the charger. A little rough. I painted the surface with flat black auto paint. The port is weather resistant from the application of silicone sealant around it inside the head.

The usb board prior to sealant being applied

The usb board mounts to a small wood block (where would my lights be without some wood!!) glued to the inside of the head.

I used a 46 mm SRK driver board to support the new driver. The original from this light got lost someplace around here during the wait to finish. Mtnelectronics has these old ones on a $2 clearance. I used some kapton tape to cover all the mount points on the other side of the board.

Yes those are some strange holes bored in the board. Explanation to come.

Those holes are to secure the board in the head. Rather than just rely on a friction fit I wanted machine screws. In part that was because of an error on my part as well as I knew this would go together and be taken apart a few times. I used nylon screws and they are well recessed to avoid cell top interference.

I used a 17mm driver from Lexel. It has Narsil, 2 x 7135 and no FET. I added the kapton tape to the main board after these pictures were taken. Inside the head you can just see one of the two threaded sleeves I epoxied in place for mounting the driver board and the copper front plate to.

A shot of the front plate with a threaded mount visible inside.

The other side of the copper plate with the TP5000 charger board. I mounted the charge indicator led through the copperplate. It is visible inside the lamp house on top. I was going to insert it through the side wall of the body but changed my mind as the wiring was becoming crowded.

Another shot of the driver end…

The odd shaped cut out in the copper plate is to provide ample space for threading the wires to the led.

A closeup of the head hanger. I mounted the aluminum disc in the drill press chuck after tapping the center hole 1/4x20. Then spun it and used a file to smooth, finishing with a couple of sandpaper grades. I used a coupling nut, drilled a hole sideways and added a split ring.

I made a maddening error. After checking and double checking the 2 color, 3 lead, indicator led connections for the charger I still managed to mess up. The convention with these boards is to use the red color/led to indicate a charge in process and then the blue to indicate charge completion. I got the leads reversed. :person_facepalming: I don’t know if I will tear down and switch the leads or not. For now I am contenting myself with the rationale that the Blue light indicates “Being charged” and the Red light indicating the light is “Ready to use”. :person_facepalming: Of course that is the opposite of the other lights I have with chargers built in. We’ll see how that goes. :blush:

Here it is in full charge mode…

Anyhow it was fun and I thought I’d show this.

Easy when it is PET. That’s the same plastic used for soda bottles and a myriad of other products. Doesn’t crack or break easily.

There is a rubber o-ring that fits inside the head under the jar bottom. Tightening the screw in the jar bottom compresses it against a slight ledge inside the head.

Here I was being a smart arse with the charging comment and ten minutes later you post a picture up. :blush:
You are good Don.
Love the style and your imagination on this build and to top it off it works. You know the wiring the wrong way round on the charge light will eat you up. :slight_smile:
I’m going now. :+1:

Thanks for the comments. I have some spare parts; phosphor domes, royal blue emitters, charger boards, micro usb ports, jars, SRK driver board, a Lexel Narsil driver that doesn’t have a home yet as well as a second aluminum scrap disc… just about everything but another SRK. I might have to get another for a second “improved” version. :person_facepalming: If I had a lathe I’d turn a one piece aluminum cap.

Nice version! The use of remote phosfor should give the lantern a very smooth output! Thanks for the detailed posting.

Cool :+1:
I warned you about those 3 pin LED’s :smiley:

Yes, you did!

I’m thinking of getting some red/green ones I found on ebay if I’m going to go to the trouble of changing it. Red = charging, green = OK to go. And then maybe an indicator led (I have assorted colors) like the switch led on the Q8, but inside, through the copper plate, like the charge led.

Should be nice :+1:

Awesome job on this! :laughing:

Thanks Den. I am quite happy with it. Thank you very much for the idea. As yours has impressed people you know and camp with mine has done the same here. I bought one of the soft pouches from Banggood that some have bought for their Q8. This fits nicely. Now I have three, each a different color to differentiate between the lights they are used with.

Thanks for the update Don. I really love these types of builds not only to see the skills members here have but for motivation as well. I wish there was a few extra hours in the day. :beer:

So the book case is finished? :person_facepalming: :stuck_out_tongue:

For the time being, which means the next few days before Christmas, I am done with the bookcases. I glued the lattices into the frames a day or so ago. (not the highest quality images, but they convey the idea.)

I put the final clear coat on the doors Monday. (Images above are the backside of the doors; image below shows the front side)

Next is to take them up to our sons place for Christmas. There we will affix the shoji lamintated paper to the backside with double stick tape and then insert them into the case fronts.

Finally we need to install the led strip lighting inside the case, behind the front lipo on each shelf. That’ll take some soldering / wiring.

Then that project is done. More waiting in the wings.

That is a real work of art work just in the latices. The cutting out and assembly must take hours. Thanks for the update pictures. :slight_smile: :beer:

The sticks that make the lattice are called kumikos. The kumiko were table saw ripped to be 3/8” x 1/2” with a blade that leaves an almost perfectly smooth edge. The edge is fine enough that when gluing one ripped piece to another the joint is perfect after being clamped. But the surface has small arcs that show when you look closely; so no good for a surface that is to be stained/finished. A little 220 sandpaper action is needed. The size was actually slightly larger than 3/8 x 1/2.

There was some trial and error to begin with to get the correct depth of cut to make the overlap level.

Then they were gang stacked and clamped down to the work table. I made a jig that fit over the group and could be clamped down. The router with a 3/8” straight cut bit then cut the half laps in one router move, left to right. Re-position the jig and repeat, repeat, repeat…. I made spare kumikos.

Then the kumikos were laid out and joint by joint sanded to make a nice fit. Everything was labeled and marked to keep the kumikos in sets to ensure a good fit after the hand fitting. An early experiment showed there was sliht variance in widths after ripping the sticks. The variance is very small, not enough to bother regular joints in the cabinet cases, but for the kumiko overlaps I wanted better. Traditional shoji doors are all hand cut with those cool Japanese hand saws.