P718T Chimera build

This project combines parts from SRK style lights and a Boruit RJ-2013 style light to create what I hope will be a high performance light at a price far less than anything comparable that’s on the market. The RJ-2013 head is grafted to part of the SRK head and will use two battery tubes, a SRK V2 fet driver, XHP70 N2 5A, and powered by 8x NCR18650B in a 2S4P configuration. Target current is 8 amps. Photos will be added as stages are complete.

Stage 1: The head

The SRK head was cut off with a hacksaw leaving three fins and the end sanded smooth.

The fins were filed down to the level of the low spots between them and a bit more to remove the anodizing.

The point at which the RJ-2013 head attaches to the tube was enlarged using sandpaper wrapped around a pill container.

Almost, just a bit more sanding.

The pieces were sanded to create a tight press fit with JB weld applied to both inner and outer surfaces. The switch portion of the SRK head was tapped into place in the RJ-2013 head and allowed to cure. The seam is covered by a black silicone o-ring from the RJ battery tube and is no longer visible. Here’s the new head next to a standard SRK.

The RJ-2013 style light was unmarked and purchased on e-bay. Unlike the Boruit mentioned in a thread here on BLF the one I received had a press-fit driver and the emitter was mounted on a plate similar to what is often done with srk lights. It did not have the thin screw in pill.

Stage 2: Heatsink/pill nearly complete - photos soon

Stage 3: Emitter, driver, wiring

Stage 4: Battery tube mods and coupling

Stage 5: Adapt tail switch, handle, and mount to SRK tail cap

Stage 6: Final assembly and beamshots

P718T Chimera
P7 = XHP70
1 = 1 emitter
8 = 8 cells
T = Thrower or throwy (as opposed to F for flood or floody)
Chimera for the mythological creature that is a combination of creatures or the genetics term for an organism that contains two distinct dna sequences.

Apologies for the delay. Photos soon. Pill installed and awaiting an opportunity to cut a pocket for the star. Decided to do so after install to make it easier to handle and compensate for inaccuracy due to manual fabrication. The completed head weight is what I’d estimate about 50% more than the total weight of a 4 emitter srk. Still waiting for the 8x ncr18650b that will power it. The original light, even with the lb emitter, had a nice tight hot spot with very faint spill at 12 ft and I suspect the xhp70 will be impressive.

looks good!
really cool and hot light man!

Well this is certainly different. Its looking good so far. Love the OL style of join. All the best for the completion.

Better to go slow and sure than to race through with regrets at the end. Liking the concept and the build a lot :+1:

Phil

Taking my time to insure the pocket will be just right. It would be so easy with a lathe. The eight NCR18650B I ordered were delivered today. That means I can start on the battery tube tomorrow. For now here’s a photo of the head attached to one tube with a 4 pack of the 18650B and a 3” long piece of 3” round bar to show things in proportion. The bare head is close to the weight of eight 18650B thanks to the now permanently installed shelf that was formed from a 1 inch piece of 2” round bar.

I finally got around to the battery tube. I cut out the center of the tailcap and using a file smoothed and enlarged the non-thread side to fit on a tube segment that had been cut off on the threaded side of the o-ring groove. The ridge was removed with a file, parts cleaned, and the cut off tube was pressed into the new opening in the coupling and attached using jb weld. The segments were assembled to insure contact of the bare alominum ends and to align the battery slots. The scratch in the photo was the result of hacksaw slipping and skipping (perfect for the ‘what did you screw up today’ thread). The flash makes it look worse than it is - I’ll deal with that later. The jb’d joint of the tube segment (the one with the scratch) and spacer will be reinforced with screws in the near future. By mounting the tubes on an unmodified srk head I determined the battery fit is just right with good spring pressure and no rattling when shaken. If all goes well I’ll cut the pocket for the star tomorrow.

Bad luck about the hack saw slip. You could do an OL mod and file grooves and polish them at strategic points just for the looks.
The mod itself though is coming up a real treat. :slight_smile:

Really digging the concept and admiring your work. I’m a big fan of press fit solutions, but have mostly used them to make thermal paths. Now you have me thinking bigger. Thank you and keep up the good work on this light. :slight_smile:

You can bead blast and polish it? I like your work, very cool!!! :+1:

This has been idle for a while but a few steps toward completion. Still need to remove the RJ-2013 style light’s tailcap to extract the switch. When the aluminum was pounded into the center the depth was insufficient to use the reflector as it was. I finally resolved it by removing the reflector’s base but I sanded it down a bit too much. Fortunately the temporary thick o-ring works and the extra space will allow o-rings on both sides of the lens. The copper centering ring is attached to the reflector with a light layer of jb weld and was formed from a piece of 3/4” copper water line. Wires are 20 awg silicone. The mcpcb is affixed with arctic alumina adhesive to help with centering and drilling but will receive screws installed and the adhesive removed and thermal grease applied. The emitter is an xhp70 n2 5a 80+ cri.

Running the same emitter in the Super Courui, I call it my Storm Light, real nice warm tint, cuts thru misty rainy,snowy foggy weather very well! I frosted (diffused) the dome and diffused the bottom of the reflector to the base coat, then lightly stippled the reflector with Hi-Temp Clear, and a UCLp lens, really nice beam now! Very good CRI, I was pleasantly amazed! :wink: Great work! :+1:

The tail cap of the donor RJ-2013 was securely glued but after a night in the freezer the glue failed and the cap came off with minimal effort. I was pleasantly surprised to find an omten pbs-101.

edit: After removing the contact board I see that it is similar enough to the srk contact board that it will fit. With cells in 2s4p spring bypasses might provide too much current so I’ll leave them as is. The only thing I’ll do to the board is replace the wire with a larger awg silicone insulated wire, touch up a questionable solder joint, and clean up the flux residue.

Driver, switch, and temp sensor wired and installed. Arctic alumina not fully cured and NCR18650Bs charging. Reflector and lens need a light cleaning but i plan to try it out later today and post photos including beamshots after dark tonight. I’ll post photos of beamshots from my Courui D01 for comparison since that’s the only light I have with a similar size reflector. I still need to cobble together a tailcap to accommodate the tailswitch but will test without .

A set of 8x NCR18650s should produce some really good runtimes.

@KawiBoy1428 I plan to use the same method on the reflector but I’m curious how bad the dark cross will be with the reflector still smooth.

Your about to find out, so are we! But it depends on what you deem good acceptable or not? But you do have avenues. I would start with diffusing the dome first, then the bottom of the reflector about 2mm up, certainly if the beam is ringy, then ever so lightly, stipple the reflector if not totally happy with the first 2 steps, IMHO. You can always hit it again it’s amazing what a light spritz of clear can do. :wink:

I have just diffused the dome on a few XHP50’s /70’s and in smooth reflectors and accepted the light cross it projected because the rest of the beam was really sweet! I have a XHP50 in a L2 with just a diffused dome that I will not touch even though this artifact exist in the beam, but to me most acceptable. It also depends on the reflector itself right, as in the position the emitter is at or to the reflector, focused, de-focused ect.

I had used and abused this Courui reflector to the point I was going to toss it, but when I changed the XHP50 to a XHP70 in the Super Courui, everything came together! Sometimes you get lucky! :smiley: :+1:

All the luck to ya, can’t wait to see how this turns out! :beer:

Photos delayed. Started out with no light and it took a while to find it was caused by a continuity problem with the tube coupling and now I have to figure out why the mode changes are flakey. Then comes solving the big dark hole and cross in the beam which is otherwise crazy bright with the 2s4p NCR18650Bs. Not ringy, just the cross and hole. Thermal path seems to be effective and on the highest level the head heats up pretty fast. Temperature step down happens at 2 minutes and again about a minute or so later so that’s one thing working properly.

I did a heavy stippling on the reflector I cut down and a light stippling on a reflector from a defiant 3d I cut down. The light stippling helped but there’s still a moderate donut hole in the beam. The heavy stippling eliminated the cross with no hole but it’s pure flood due to the way I cut the reflector. At 60’ it illuminates an area 80’ wide. I also suspect it should be brighter. When the meter I ordered arrives I’ll check the tail current. I suspect it is being limited significantly by the ground path through the tail board screws. If that is the case I’ll clean off the anodizing on the flats near the screw holes and make some copper clips and solder them to the switch side of the tail board for a better ground path. I found a 68mm wide 34mm deep 5° smooth reflector that should work well. I just need to reduce the diameter of the flat at the top by 3mm and remove the 0.8mm thick base and it should slip right in. Pretty much resigned to shaving the dome.

Still cobbling together parts to make a tailcap to fit over the switch.

Part of a run pulled loose from the rj tailboard while bending copper to improve ground path. I cut runs on a srk board and transferred the switch. Still minus jumper wire but ready for current tests.

Received the double springs from ebay seller. After a little cutting, bending, and streching they’re mounted on the tailboard
Tomorrow I replace the 7135 on the driver, re-wire, and test tail current. Looking forward to the arrival of the 5° reflectors.

The 5° reflectors were processed through usps isc chicago and are scheduled for delivery by 3/16. Looking forward to seeing what the xhp70 does with a narrow beam reflector. The narrow angle should produce good throw and eliminate the cross and hole.