Outer diameter of the threads (on the male end) is 23.8mm. I measured pitch distance at 1.25mm. I assumed it was metric, but that’s consistent with 15/16-20. M24x1.25 doesn’t seem to be standard.
Can anyone confirm if 15/16-20 works? I have limited machine shop access at work but I don’t think that’s a tap (or fastener) that we have.
Sorry, I don’t know. Can I ask what you have planned? I have an FW1A and have thought about making a “turbo head” - basically a replacement bezel that’s taller and flared out to accommodate a bigger reflector. Ideally it could be swapped with the stock setup in a matter of seconds. Unfortunately the need for threading is holding me back.
M24x1 is what I’ve been told. I can message you the CAD data I was sent.
I was trying to make a brass bezel for my FW3B that I converted to single emitter with a reflector, only slightly longer than the stock FW3 bezel. But now I found an opportunity to buy a brass FW1 bezel so I think I’ll just get a reflector to match that one.
Oh cool. FYI Kaidomain has a just about perfect smooth reflector for the FW1A bezel. I can get you a link if needed.
I’d like the link
I checked my receipts and spare parts. I actually ordered two reflectors and only ended up trying the first one, which worked well for me.
This one requires a little sanding to reduce the diameter. It’s also a bit too tall. I haven’t sanded-down the height yet but it shouldn’t be an issue to do that. As it is, there’s a small gap at the base of the bezel. Note I’m using a 1.5mm MCPCB so if you’re using the stock 3mm (?) MCPCB the gap may expose the O-ring and definitely require sanding. I tried a few different LEDs and don’t recall the beam profile being ugly with any of them. I have an XPL-HI in there now and it looks great.
Here’s the other one I bought but haven’t tried in-light. Diameter-wise it fits without modification. It’s shorter so may work better with the stock MCPCB, or if you have a converted FW3A with the shorter bezel. The potential issue with this one is the LED opening is much smaller at 5.2mm. The diameter of the reflective area is smaller so it probably has less throw than the one above.
Thanks for the detailed explanation!
I agree that the bezel thread conforms to M24x1mm spec.
FW3A external thread measurements using calipers and thread wires:
Pitch: 1mm
Major diameter 23.85mm
PD 23.29mm
Calculated M24x1mm external thread specs:
Min Major Dia: 23.89mm
Max Major Dia: 24mm
Mean Major Dia: 23.94mm
Min Pitch Dia: 23.23mm
Max Pitch Dia: 23.35mm
Mean Pitch Dia: 23.29mm
The measured pitch diameter matches the calculated mean tolerance value of M24x1mm. The major diameter is a little small so the threads are slightly truncated.
Thanks guys.
Has anyone tried this reflector? It’s the one recommend on the tactical grizzly site.
I haven’t tried that one but the measurements look about right. The diameter is probably about 1mm too small bit you could give it a couple wraps of tape to make up the difference. It has a 7mm emitter opening which is good. If you use a non-stock MCPCB it might be slightly short.
I’d wager that one is better than the second one I linked. The first one I linked is going to give you the maximum possible reflective area diameter, so probably slightly better throw, but require some modding.
I’m now on a wild goose chase to find stock hardware with compatible threads for this light and others (e.g. I think the Thrunite T2 is M27x1.5, IIRC my measurements last night).
I want to find an affordable stainless or brass nut, fitting, etc. that will serve as the base for a larger head. I could then cobble together some other pieces and braze them together.
This isn’t exactly the same, but I was considering using one of these spacers/bushings to make a bezel.
https://www.lowes.com/pd/Hillman-7-8-in-x-1-in-Plain-Steel-Standard-SAE-Flat-Washer/3012332
Specifically I was going to use a brass one. But 1" OD matches up perfectly and you’d barely have to remove any of the 3/4" ID to thread it. The address says 7/8" ID but the product is actually 3/4", which I think you’d need for the business end.
You could do slip fit parts + adhesive. Super glued parts would be removable with moderate heat, then the residue dissolved with acetone, so the setup would be reversible with some effort.
What head are you wanting to adapt?
That looks promising, especially in brass. I don’t have much machining experience. Would you thread it with a tap or lathe? Could either method work?
That’s a good idea and would solve the issue of finding the perfectly threaded parts.
Actually the first mod like this I want to try is with a D4V2 since you can buy stainless bezels from Hank. I’d make a custom quad optic by modding and gluing together four TIRs. I’d braze some kind of cone-shaped material onto the SS bezel to flair it out for the larger quad. I then need some kind of bezel on this cone so I can drop in the quad optic, glass, and screw it down. Hopefully that makes sense how I tried to explain it.
It would be sort of a quad thrower with the aux lights still able to shine through.
I’m no master machinist myself, but I don’t think hand tapping it would be a problem. Boring out the inside would be more accurate on a lathe but I think it’s perfectly doable with a drill press.
Then again, if we were skilled with lathes it would probably make sense to just start with a brass blank instead of these spacers. I used to be good with them but I’m too rusty to jump on the shop lathe for a personal project.
Hmm, I’m halfway tempted to give it a try. I see amazon has m24x1.0 tap options for $25 or so. Not sure I can justify spending hobby money on such a limited use case though.