Sunnysunsun's 8th Old Lumens Modified Light Entry [Completed]

This is my Water cooled XHP70.2 Playskool Flashlight Project!

The video gives a short summary of the features and some beamshots.
This is a long post made in several sections which you can peruse through at your leisure.

1. The backstory
2. The parts I used
3. How I put everything together
4. Beamshots

1. The backstory

I got the inspiration to get the Playskool flashlight and modify it into something brighter when I saw a reddit post where people were discussing their first childhood light.

I purchased this light last summer from a nice grandmother who was selling it on Craigslist for $5. She was surprised I wanted it for myself. :smiley:

Taking it apart was a monumental effort. This light was built to take all the abuse young kids could throw at it and continue functioning. I had to cut off the frontal blue bezel with a hacksaw to have any chance of removing it from the rest of the host. Even with the bezel sawed in half, I still have trouble taking it off which shows the robustness of this light.

Originally I had been planning ton putting my D18 into this host with a fan for cooling but I wasn’t satisfied with the outcome. It was very front heavy, the fan wasn’t effective enough, and worst of all there wasn’t a way to press the D18’s button without drilling another ugly hole into the host.
I abandoned the host I had in search of another Playskool flashlight because the hot glue I used was so firmly stuck to the yellow plastic. This year when the Old Lumens build contest popped up again, I decided I’d get to work on this light. I planned out the light and purchased the parts I needed from a mix of FastTech and Aliexpress, and went on the lookout for another Playskool Flashlight I could use.

This search was rather futile since no one nearby Toronto was selling one, and the ones available a good distance away were in the $40 range and being sold as “vintage.” I was unwilling to pay so much and with time running out, and my other parts having arrived, I decided in early December to try to remove the hot glue using a heat gun.

Luckily before trying that, I did some searching online and discovered that isopropyl alcohol helps to loosen the bond of hot glue. I dumped a 500ml bottle of IPA into a container and soaked the shell of my Playskool flashlight in it (shown in the photo above on the right).

After a lot of yanking, I finally managed to get all the hot glue out, but broke my fan in the process. Luckily I had ordered a spare once since I hadn’t expected to be able to remove it from the mess of hot glue.

Finally I could start this build!

2. The Parts I used

Reflector: I chose a Convoy L6 Reflector which I had originally purchased for a different project which never quite took off. It fit pretty well in this host but still required some hot glue for support. I was considering using my FT03’s reflector but this one worked out alright.

Emitter: I picked a 3000K XHP 70.2 on a 20mm DTP MCPCB from FastTech. I wanted to replicate the incandescent look but unfortunately I later realized that 3000K just isn’t quite yellow enough and the brightness on turbo certainly won’t be fooling anybody :smiling_imp: . I won’t be buying from FastTech again since the MCPCB my emitter was mounted on wasn’t flat and I had to sand it extensively using sand paper to make it flat.

An special thank you to klrman who sent me one of his spare centering rings for my L6 reflector this summer for free! The L6 reflector I had previously purchased from FastTech didn’t come with a centering ring so I recommend buying from Simon instead. The intended light for that centering ring never materialized but I’m glad to say it has been repurposed for something even crazier! :sunglasses:

Side note: look at how much light is lost in the Convoy L6’s reflector’s centering ring in the photo on the right! My Playskool flashlight is lit up from the inside even though I pushed the centering ring all the way flush and it’s a perfect fit from original Convoy parts. I wonder how much light you Convoy L6 owners are unknowingly losing!

Driver: I put my old MF04S driver to good use! I had contemplated throwing it away after swapping my original MF04S driver for one with Anduril made by Lexel but I’m glad I kept it and was able to repurpose it for this project. In the photo below, I am testing it for the first time to see if my driver still worked after being haphazardly stored in my parts bag for so long.

I wanted to be able to run the XHP70.2 on a high brightness setting for an extended period of time so a good cooling solution was a must. I decided to try my hand at water cooling which worked excellently. I am able to run this light at the 2nd brightest setting for ages and never noticed dimming.
Here are the other parts I used for my light to implement USB charging and my Water cooling system.

3. My Build Process

I was a little limited with what I could do since Makerspaces around me were closed due to corona so I didn’t have any power tools. I overcame this by thinking up a design which didn’t need any holes to be drilled and cutting the plastic housing using just pliers and occasionally my hot soldering iron when I had to make detailed cuts (Luckily the room I was in had good ventilation because melting plastic stinks :confounded: ).

My understanding of electronics is rudimentary at best but I have a couple of friends studying electrical engineering who were able to help answer some of the questions I had. I am getting better at soldering with practice. Installing Lexel’s aux board last year were a bit tricky, but nothing in this project required soldering on such a small scale.

I began my build process with the most important part of my flashlight: the light producing components. I used 18 gauge silicone coated wire for my emitter, and after sanding the MCPCB excessively and also sanding the top of my heatsink, I added a drop of thermal paste then super glued the MCPCB to my heatsink. I then retested the emitter with a small boost circuit to ensure the emitter was still functional.
For the reflector I glued on the front glass. then glued on the plastic centering ring, and finally glued the whole contraption to my MCPCB and tested it one more time.

Now that my light source was complete, I could begin the packaging process of how I would fit everything into my host. What a challenge it would be, with hurdles at seemingly every turn.

I began the assembly process by approximating where I wanted to place all the parts in my Playskool Flashlight’s body. My first hurdle was the discovery that the Playskool flashlight is less roomy on the inside than I had imagined. It would not be possible to put all my components inside the body of the light so some things had to be left sticking out. I chose to put my radiator and fan outside of the body, and the rest of my components including the batteries inside the body which still ended up being a very tight squeeze but I just managed it after cutting away almost all of the yellow supporting pieces of plastic which had been in the way.

The pump I purchased had an oddly shaped passage for the water so my tubing had to be a little loopy to accommodate it which made the tight fit even tighter.

With the general shape in place, next I worked on the switch situation. I wanted to use the original switches to control the light. The way the buttons worked originally was the top one is a sliding On/Off switch while the bottom one is a momentary switch that gets held down when you hold the flashlight by the handle.
This makes things easy right? A momentary switch to control my driver, just like the momentary switch MF04S had, and use the slider up top to control my fan/water pump? Unfortunately this wasn’t feasible since the momentary switch at the bottom is usually held down anyways when you’re holding the flashlight by the handle. so it would be very inconvenient for it to control the driver.

Instead, I connected the driver’s switch to the top On/Off Slider, and my cooling circuit to the momentary switch at the bottom. (See video for demonstration)

The way the Playskool Flashlight’s switch is built also presented an issue. The middle metal piece is shared between the two switches which means if both are activated at the same time… I don’t know what happens nor do I want to find out. The top part of the switch is connected through the driver and the bottom part of the switch (for my cooling circuit) would be connected directly to my batteries). I’ve tried to draw it out in the image below.

I checked in with my friends who are studying electrical engineering to see if this would be an issue but they were unsure and recommended I isolate the two circuits to avoid any potential problems. I did this by gluing a piece of 16 gauge wire with most of the insulative coating intact to create a separate circuit for the batteries’ power to run through. The two circuits thus never make contact with each other.

For my cooling circuit, I connected a buck circuit to my batteries to provide 5v to both my fan and my water pump rather than 8.4v which would be unnecessarily high.

After some real world usage, I also added another shut off switch to my cooling circuit so I can carry the flashlight by the handle without accidentally turning on my pump and fan. Through testing, I also discovered that the inductors on my driver were the first things which got hot so I added a large, thick washer to my driver using some hot glue, and some thermal paste on top of the four inductors for better heat transfer. I later added another small piece of aluminum to improve the heat sinking a bit more (not pictured here). Originally I had planned to have another heat sink for the driver, just like the one the LED has, but I simply couldn’t cram it into the host along with all my other components.

Back to my fan’s situation, I ran into another hurdle here because my computer fan could only blow in one direction. This meant that I would have to mount it with the side with the moving blades towards my flashlight’s body. I didn’t think this could be done without the fan rubbing against the host and breaking itself but this is where my spare parts came in handy. I used my old broken fan’s housing to act as a buffer against the flashlight’s body so that my working fan could spin freely, and this buffer allowed for increased airflow as well as putting the fan in a deeper, safer position for my fingers.

Pictured in the rightmost photo is the syringe I used to help film up the hoses and heat sinks with water.

At this time my soldering iron died on me. No heat in the tip when plugged in! my Weller barely lasted a year of use but I’ve lost the receipts long ago. The inside of the tube is filled with some kind of white chalky material so I can’t even take it apart and find the disconnected wire :person_facepalming:

After buying a new soldering iron for less than $10 to complete this project, I soldered on some 18 gauge wires to my battery holders and added some thin wires for USB charging.

With USB charging I encountered another hiccup. I had wanted to connect both USB charging boards to a single USB cable out so I would only have to plug in one cable to charge all four batteries. My USB charging boards however were built in a way which would cause a short circuit if I did that, so I had to have two micro USB connectors going out of my light instead.

With all this finalized, I tried to close the two halves together but they wouldn’t close seamlessly! After some investigation, I determined my battery holders with the batteries inserted were the just too bulky so I took some pliers and cut off the excess material on the edges of the battery holders to slim them down. When all that was done, I glued in the parts using hot glue where a buffer was needed since stuff like the reflector didn’t fit into my host perfectly, and used some super glue for the areas which required some extra strength due to a low surface area of contact (the fan).

I also added a bump of solder to the top half of the switch to make it activate more easily.

This is my final result!

I am using some cables ties rather than glue to hold everything together for now, just in case I need to make any fixes on the fly or want my batteries (which I borrowed from my MF04s) back.

Thanks for reading, hope you enjoyed this lengthy post!

I must say that I am glad I finally got this project done. So many little things didn’t line up as I had imagined they would, and each one required its own creative little fix.

4. Beamshots!

An indoor beamshot

FT03 XHP 50.2 (left), Playskool Flashlight (right)

Haha, that’s awesome

Also… That pic is 10 MB and seems to take a while to load. You might try a smaller file or faster host.

Yep, thanks for the info! I was hoping blf would do a bit of compression but I guess I’ll have to do it myself. Originally it was a 16000X4000 pixels large so I’ll trim it down a bit. I only just got image hosting working today. For some reason imgur just refuses to work for me on BLF.

I skimmed it down to 2400X600 now which loads much quicker and still looks decent

Imgur doesn’t support BLF’s markup, unless you use the HTML and put it in the advanced post editor. Otherwise you can get the image’s direct link and use the insert image button.
For more information

I’ve resorted to the german site in that post you’ve linked to and it has worked much better than imgur. I’ve also discovered that switching between simple and advanced post editor while editing a post screws things up royally. Thanks for your help!

Really nice mod Sunnysunsun. Cooling to the extreme in a plastic torch. :+1: :beer:

My Entry is done and Video is up in the first post! It took me all day to write up and will be a fairly lengthy read. I counted about 2000 words!

Let me know if you have any questions or if anything didn’t look right/was missing.

Very nice mod Sunnysunsun :+1:
I like the Playskool flashlight idea. Not an easy task putting that idea into a working successful light.
Congratulations you have officially joined the handful of Water cooled flashlight modders :person_with_crown:

Nice ! I really like seeing that beam coming out while seeing the Playskool logo :+1:

Thanks! Glad you two enjoyed it :smiley: The trickiest part was cramming everything into the not so large host itself. It was a very tight squeeze. I’m sure the XHP70.2’s brightness isn’t what anyone expects when seeing a Playskool light.

I agree, Sleeper Playskool Flashlight sounds cool :sunglasses:

Cool :wink: Well done :wink:

Very nice. Makes me wish we had kept one of the Playskool lights when we closed our preschool.

Using a Playskool light as a host was an extremely bad idea :person_facepalming: , but you made it into a glorious succes and it was much fun to read, nice! :smiley:

One thing you can be sure of each year is that there will a curve ball you didn’t see coming - and it’s yours this year for me.
Thinking of ‘what’ to do is often the hard part - imagination. Well done on this unique build, the water cooling is so cool! (literally)

Now that’s an upgrade.

Do you still have this? If I was you I would try to keep it as a family heirloom :laughing:

Haha I drained the water from it and have it in storage with the rest of my stuff at uni while I’m home for the summer.