One of my last orders from int-outdoor i asked Hank if I could buy a KR4 tail board. He wanted to know what it was for , must’ve been curious if one of his lights had a problem. I explained i was going to use it on a D4 and he threw it in the order :partying_face:
I have lots of pics but instead i’ll keep this short. I made a new (al) inner sleeve and (ti) tail to house the KR4 tail board plus led4power lighted tail board (that i broke previously) , an ATtiny85 and some smoke and mirrors.
I think we’ll need to see the rest of your pictures, and preferably a full build log, to decide whether you’ve gone too far.
Okay maybe tomorrow 
This guy gets it. Panda, that looks great.
Oh my, pp! What a creation!
Great mod pinkpanda, very original to have thought to adapt the infinity mirror to a flashlight.
Thanks Tally-ho. It’s not the first time I’ve done something like this
Very Nice and Beautiful. 
Shame on me for not checking your mods more often, great stuff pinkpanda.
lol, I was just saying…
I know there’s a lot going on on BLF nowadays.
Thanks cncman. I’ll be watching your pot lid build with interest :nerd_face:
???! What the hell is that? Is that a rail gun in the tail cap! That’s so sick! This is the coolest flashlight I have ever seen! 
Do you make flashlights for addict’s? In all seriousness, that is so AMAZING! 
Awesome!
This light deserves the bling
Mmm at it again 
I am still amazed at how you came up with that.
Not sure where this idea originally came from but hasn’t everyone thought of aux lights on both front and rear 
Anyway i thought these new tail boards from a light with an e-tail switch was the way to do it.
When i received the kr4 tail board it had pro’s and con’s. Pro - the button part was only taped on. Con - the board is wider than the d4 tail board.
Other parts i wanted to use was part of a led4power tail which i managed to break previously. Since i cut some of the traces i surface wired them. I also made a little extra space at the back for an ATtiny85. It’s probably overkill having something that big controlling the leds but 1. I can program it and 2. I’m not good enough with electronics to do really small stuff
I used dental mirrors since they are conveniently the right size. Working with glass is a trial in itself
I used my lathe with a tool post spindle and small milling bit to make the holes in the back of the mirror. It took a few goes to get it right
Your typical infinity mirror works on 1 mirror and 1 two way mirror.
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I was initially going to use 1 mirror and 1 glass lens but after some experimentation decided to forego the lens and just stick the reflective film to the top of the mirror.
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Having the reflective film stuck to the face of the mirror has a couple of drawbacks. 1. the mirror and reflective film are very close so the ‘depth’ of the mirror seems shallow (the light disappears faster) 2. the light needs to pass through the glue on the reflective film which kind of blurs the light with each reflection 3. the reflective film is exposed to possible scratches etc…
So i considered using the glass lens anyway just for durability then i had this idea. I’ve got a tempered glass screen protector for a phone my daughter no longer owns. It took me 3-4 goes to try and cut it into a circle without wrecking it but it save a bit of space compared to a regular lens. In retrospect i could’ve stuck the reflective film to this so the light didn’t pass through the glue.
4 layers. Led board glued to the mirror back, reflective film stuck to mirror face, tempered glass stuck to reflective film. The infinite mirror section is one solid unit now. I put a layer of kapton tape on the kr4 board then cut holes and made solder connections for the programmed ATtiny85
I then used a dremel to reduce the diameter of the board. You can see i cut halfway into the vertical traces (terminology…???). I wasn’t worried about dust since the mirror is now a sealed unit. Also made a plastic spacer to take the pressure of a retaining ring
A little about the ATtiny85 programming. Aside from a couple of members here on BLF posting great ‘how to’ flashing threads this hackaday post was also an inspiration to have a go at it myself. Other than 1-2 adafruit trinkets i’ve only flashed one ATtiny85 with the exact code in the hackaday post. I used that ATtiny in the tail of my v11r …
For this D4 I wanted to make the light pulse like a heart beat I couldn’t work out how to modify the above code to make it pulse so i searched and found this code. I had to change the pin out and something else from memory to get it working but it wasn’t a ‘pulse’ as such just a light pattern. After some playing around with the code I came to the conclusion that the code was incomplete and I had to add more code for it to beat like a heart. For those in the know i’m sure it’s not hard for you to work out but I was kinda proud of myself for working it out. If anyone is interested i can post the full code.
Onto modifying the host. Obviously with the kr4 tail board i need to use some kind of inner connection… like…… an…inner… tube… I know, innovative right …?? 
It’ll be lined with kapton tape for electrical isolation and will connect directly to the battery + I also had to skim the inside of the D4 battery tube, I have everything on the limit of ‘just fits’. Unprotected cell ‘just fits’ in the sleeve, the sleeve ‘just fits’ into the battery tube.
Making a new tail. There’s no way i was going to get this to fit in the original tail so a new one it is. Of course, it gave me a chance to play around with the new tool post spindle i finished a few weeks back 
Also made a brass retaining ring. It was maybe a little too thin to drill holes for installation via tweezers. Also had a near mishap. I didn’t realise until after i had made it that the retaining ring was very close to shorting across the two contact pads on the kr4 board Fixed that later with a dremel
Also not much space between the inner sleeve and brass retainer. That would be a dead short and once during the build i did get a dead short. From memory the issue was at the + end though.
Final assembly on the tail. I was pleased that it wasn’t too much bigger than the original tail but i was disappointed that i managed to get dust all through the mirror prior to sticking it together. Also you can just make out the edge of the glass/mirror/film…??.. around one side of the tail. I really need to learn more finesse 
One thing i haven’t finalised is the electric connection at the front of the inner sleeve. You’ll see a bit of it in this video. Not much chance of it shorting but the possibility is there. It may not be too visible in the video but there’s a layer of silicon rubber around the driver spring plus the bit of copper tape you’ll see floating around (source of the possible short).
It’s full of stars!
Very cool idea.
wtf? Lol ! A firecracker in the butt…
Brilliant!
Impressive :o Again
I have a feeble brain pp. I guess you like imaging my head doing exorcist imitations because that is real. 
