I'm thinking to try building a custom single cell wide throwing light for helmet mounted use while biking. Notice I say "wide throwing" so not a pencil beam, nor a lot of flood (the handlebar mounted light will take care of that). The light also has to be fairly small and lightweight.
My first thought was to build a Convoy M1 with an XP-G2. I'm also planning to use 4.35v cells to overcome the high vF issue of the XP-G2. (I'm only planning to drive it at 3A max.)
Any thoughts or suggestions? Is there a better suited combination?
Looks like a good one to go with…and pretty beefy and plenty of heatsinking
Can’t go wrong with a Convoy either
Question, you said wide throwing…then why go with a XP-G2, those make great thin beam way out there throwers, if you want wider why not go ahead and go with XM-L2 and regular 4.2vdc Li Ions? Beamshots from the below review show a nice wide thick hotspot
Hmmm I am curious about this, personally I have tried the M1/M2 with XM-L2 and I like them, but I find the hotspot a little distracting and I prefer a convoy S2+ for even illumination. However, this is for skating and only one light at a time: in your case with the handlebar flooder it could work.
I chose an XP-G2 over the XM-L2 in order to get more throw due to the bar light already giving me flood. I have been wondering if I should consider a triple XP-G2, but guess that couldn't be done (easily) in the Convoy M1. It would also cut down on runtime. I don't want a "distracting hotspot, but assumed the XP-G2's would be wide enough not to be distracting. I also thought the XP-G2 would help to get "throw" out of the M1's relatively small reflector.
Thanks Itinifni for the beamshot. I actually have a bunch of Carclo optics on hand and believe I have both of those. I've not got around to trying them though. I don't think those optics are what I want to use for "throw", but I have wondered if I should do a build with TIR's (perhaps a 10 degree or "narrow spot" type). So are there correct size optics that fit an M1? I see Ouchyfoot had one for an MT-G2. I doubt it would be an easy build though getting the fit right. Any other good hosts that fit the 26.5mm Carclo optics? I don't really want to downsize to 20mm optics due to heatsinking.
I think that you should try the M1 with XM-L2 before, the XP-G2 maybe overkill. I find M1 and M2 with XM-L2 on the edge of being too throwy for biking. It depends of the terrain and the speed, as I said they are close to being distracting for my taste. If I could adapt optics to smooth and widen the beam slightly I’d be very happy.
Triple m1 isn't too hard, I had to cut a s4 pill to use the top half as a centering adapter and the bottom half was used as a contact spacer from the battery tube to the pill since the pill sits up 1/8" higher with the triple parts. I just tore down the m1 triple to put the parts in my s6, but it was definitely a floodier light being in the m1, not as much throw either. (Not that the triple carclo optics provide much throw anyway.) I don't need the host anymore or the 2 halves of the s4 pill so if you want to try it I'll sell it to you.
I also chopped the m1 reflector in half and sanded/filed till it is a perfect fit around the aluminum spacer to help the top half stay centered. I thought it would also help throw more light but didn't seem to help a whole lot.
Ok, closest beamshot comparison I can come up with are in "C8" lights with older generation LEDs and the XP-G is only driven at 1.4A:
Mouseover: Mouse Out Palight XP-G 1.4A, Mouse Over KD C8 @ +/- 3A:
Hmm . . . perhaps I don't really need to push the XP-G2 to 3amps. I would likely use medium mode (or just a "low" if I chose to only go with a 2 mode driver) most of the time and high as a "Turbo" but I can't see needing an XP-G2 at 3A on a bike! +/- 2A should be sufficient and give me better runtimes. Maybe that's my advantage with going with the XP-G2, getting the throw I want with less current.
Well I just finished building up two Convoy M1 lights. One is an XM-L2 T6 4C @ 3.0A and the other is an XP-G2 R4 5A2 @ 2.2A both flashed with guppydrv and both on noctigons. Really nice hosts, but I don't like the matte finish (looks painted). The XP-G2 was a real pain to try to center the reflector! I also kept having trouble with it shorting even though I used plenty of kapton tape. The XM-L2 was a breeze.
No beamshots or lux measurements yet. Will post those another time.
In the meantime, here's a pic of the brothers side by side:
The XP-G2 is slightly off center due to no centering ring and the reflector spinning around as I tighten. I could glue the original XM-L ring to the pcb, but I'm not sure I'm keeping that LED in there yet.
I have both drivers flashed with guppydrv and gave them a test run last night (indoors only). Boy you have to be really quick to enter programming mode! I thought at first I had defective drivers! I tried the two mode (15%-100%) and I am afraid that 15% is a tad too low. I think I'd really want about 30% & 100% for levels (simple two mode - no memory, always starts in low). I'm really tempted to pickup the supplies to start flashing my own drivers.
Finally got the opportunity to get some beamshots of these two Convoy M1s. As previous post states, these are set to two mode 15% & 100%.
XM-L2 T6 4C @ (3.04A) on High:
XM-L2 T6 4C @ on Low:
XP-G2 R4 5A2 @ (2.2A) on High:
XP-G2 R4 5A2 @ on Low:
On my simulated wooded trail:
XM-L2 T6 4C @ (3.04A) on High:
XM-L2 T6 4C @ on Low:
XP-G2 R4 5A2 @ (2.2A) on High:
XP-G2 R4 5A2 @ on Low:
XM-L2 T6 4C @ (3.04A) on High:
XM-L2 T6 4C @ on Low:
XP-G2 R4 5A2 @ (2.2A) on High:
XP-G2 R4 5A2 @ on Low:
Few Mouseovers, each light on High, XM-L2 mouse out, XP-G2 mouse over:
So it's like I thought, there isn't a huge difference between the XM-L2 @ 3A vs. the XP-G2 @ 2.2A (yes, there still is some difference). I'm surprised the XM-L2 seems to out throw the XP-G2, though the XM-L2 needs to be driven harder to do so. Also consider that the XP-G2 is driven @ 0.8A less current, so more runtime. I'm very pleased with both beam patterns. The XP-G2's tint is a bit too rosy for my taste though. The 4C of the XM-L2 also came out warmer than I expected (I usually prefer a 5B1 tint) and is about perfect I think.
My typical set up for mtb is a multi emitter mounted under the bars w/remote thumb switch and a single helmet mounted led for look around the corner viewing and longer distance. Usually both are lo/med for uphill ascents(low for less technical, med for more rocks/ruts) and med/high depending on speed/need. Helmet remote is mounted on shoulder strap of hydro pack. I definitely prefer the smooth beam of multi optics over multi reflectors. The single isn’t a thrower, more in the 10-15 degree range that heats up the center of my tunnel ’o light. J) This is really the only time I use or want maximum output for any extended period so turbo step down is not an option I would put on a bike light. I’m old enough that moon is not enough for the bar mounted light but do want it on the helmet(for finding my beer). If I want to ride by moonlight I use the real thing. RMM’s new buck options are to me an ideal pairing of higher voltage remote packs with lower transmission currents.
FYI, a 25mm quad Khatod will fit an M1 host with shimming and give a nice medium to flood beam depending on choice of optic. The 35mm version would retro any mr11 halogen set up like Niterider or Vistalight.