Shelf-Less SRK

Top of the day to you all.

I ordered 2 SRKs from Fasttech on their claim that it was the “original” SRK. I’ve been interested in this light for some time and wanted to mod one out. Got the package yesterday from FastTech. First impressions were good, it looked like a nice host- great anodizing and feel, fit and finish are excellent. However, since I view each flashlight as a host, I opened her up……and……no pill or shelf. I can’t say I was terribly surprised, but a touch disappointed. I know what I have to do now, time for some metalwork. Since I moved I don’t have access to a lathe anymore, guess I’ll have to find someone locally with a lathe that will work on something like this. With my limited knowledge of French that should prove interesting…anyway. My plan at this point is to bore down the small lip where MPCB sort of does(n’t) sits on. I think I want to cut this down to the switch to allow for as much material as possible to be shoved inside. I think then the goal is to find copper or aluminum rod, probably start with 2” stock, and lathe it down for a press fit and cut it off at maximum thickness possible. I’d like as much sidewall, if you will, contact area as possible.



Here is what it looks like inside. The MPCB and the rest of the bits are off to the side. The XML-2 U2 3C on the noctigons are my plan here. MPCB that came with the light looks like 1.5mm thick alu.
![](https://imageshack.com/i/hlgb3aOfj)

I drew a circle around the lip to show the width of it. Hard to see here, but there is a substantial gap between the edge of board and the ID of the light. There’s no thermal path whatsoever in this thing, shameful.






Here’s the original led board inside the light.






Here’s a glimpse of the other SRK I got at the same time. Both were identical except for colour. Interesting that FT says that the gold one has better build quality, I couldn’t see any difference whatsoever. Also a peek in the background of something I put together last night, the thing with the big reflector. Can anybody guess what it is? :stuck_out_tongue:




Just thought I would share!

Pictures aren’t working for me…

They’re hosted at imageshack. I cleared my cache and it worked fine for me. Can anyone else not see them?

I can see the pics fine.

This seems to be the norm for SRK’s these days. A lot of people have gone to the Supfire M6 for a soda-can light for this very reason.

Now it’s working. Thanks!

interesting, I will follow this thread carefully

I knew that it was likely I would get one without the pill, but FT’s note saying it was the real deal was somewhat of a consolation. Now I know I guess.

Was wondering, surely some of you have bought the shelf-less SRK before. What have you done with it? Has anyone made a press fit pill? No chance on any lying around for sale somewhere I suppose? Would like to hear how of the rest of you have combated this problem. I am certainly not going throw my hands up in despair, the rest of the light is great, and can be awesome with some mods.

Well i got 1 and some more underway.
All for learning soldering and modding.
They look nice and are big, easier to work with.
I I’ll pm you tonight

How thick is the original mcpcb?

What would I do? I don’t have a lathe or any way to work with bar stock (that would be preferred) So I would sand off the dielectric layer from the original mcpcb and sand the ano off the little ledge and use some good thermal epoxy to glue the mcpcb to the ledge, then mount my Noctigons on top of that. You might have some height/fitment issues at the bezel, and thermal transfer wouldn’t be great, but it should be workable.

There are many variations in the machining in various bad SRK's. A standardized press fit pill probably wouldn't be practical. To fix this issue is probably going to run $20+ unless you can find a very generous local metal worker. This why I always recommend the M6. The heatsinking, far superior beam profile, and better build quality. The stock driver can be resistor modded very easily as well, but starts out at a decent 2.5A per emitter (~2500lm).

Here’s a good example of fixing the shelf issue:

I certainly will have fitment issues, this isn’t option for me as the thermal transfer going to the head won’t be enough. There isn’t much material touching the lip. Trying this did cross my mind tho.

Unfortunately I didn’t hear of the M6 until yesterday, don’t know why, I frequently buy stuff from RMM but whatever. Yes I know it will cost something to get it done, but in the end it rivals much more expensive lights at a still lower cost. One of these is for my father and want it to be reliable, if I have to pay a bit that’s fine.
I’ve got the V2 driver from RMM on my desk, itching to put it in!

Thanks Andrew.

Yep, you can do the mod fairly easily without a lathe. Aluminium is pretty easy to work with - I think it took me about 30 mins to make the shelf in that mod. Works very well, light has seen a fair bit of use since then.

Nice, I like what you did there. I just ordered some 2mm copper plate. I may forgo the lathe idea if this works, and after hearing that your light heats up nicely I may not go whole hog with it and take it to a shop.

Copper is great at transferring heat, so I’m hoping this will get heat into the body of the light.

May I ask you cut that piece of aluminum and got it that nice round shape without turning it?

Scribed circumference, cut close to size with hacksaw, then coarse file, then smooth file to finish.

I had practice making a 4mm one prior to that, which was a little too thick, so had to do another in 3mm.

Depending how your light is machined, you may find that with 2mm you will have to raise the LED's.

I think mine might be machined differently than yours; from what I can tell now, I’ll actually have to sink it down a bit. If I flip over the existing board which is 1.5mm I can’t quite tighten down the bezel all the way. I’ll probably end up filing the noctigons down a bit together with sanding smooth the lip.

If you have access to a drill press and hole cutters, you could make a disk by using 2" circle cutter to get a perfectly round disk from aluminum sheet.

You may need to increase the size of the hole in the SRK by drilling it out with a 1 3/4" circle cutter. Here is a SRK that had threads that this was done to before pressing into place.

Here is the disk, that I made with the above process:

You likely need to file down the above disk to get a good press fit.

Thanks for that! I may have to try that with the copper.

I'd toss the existing board. No point putting that in there, especially on top of a copper shelf.

No I don’t plan on using it in the SRK That’s what the noctigons are for. I may, however, dedome it and use it as lamp indoors. :slight_smile: