Hi Folks, first Mod Post here.
I’ve been hanging around a for while but very rarely post.
I finished this host last year, but due to other commitments never got around to building an engine for it.
Unfortunately I didn’t photograph the host build, so we will have to make do with a recent teardown.
This is how she stands now 4th from the left.
Current configuration is De-domed MTG2 on Noctigon, driver is BLF17dd Zener.
Battery Config is 3s,
The handle is a modded Magic Fire Host fron CNQ Here
Adapting the magic fire host as a handle has given me the ability to use 3 X 18650’s & a ton of room for extra heatsinking.
The battery carrier needed modding from 3p to 3s & while at it I replaced the switch with a more robust 10a Judco & braided all springs.
I also shortened the carried to make up for the extra switch height, not a problem as I am only using shorter unprotected cells.
This is the current light engine.
MTG2, noctigon, mounted to a 25mm solid copper slug.
!!
The threaded section from memory was the pill holder of the magic fire.
it screws nicely into what is now part of the head.
What was the original Led mounting shelf in the L2 is now gone.
I bored through the head so that the copper slug can be wound up or down to the correct height for focusing of the Led in the reflector.
You can probably pick that the bottom of the reflector is modded to miss the led wires, plus a couple of needle nose grabber holes so I can wind the reflector snug up against the glass from underneath.
Not currently no, I have one on order from Cutter though.
I thought I’d see what would happen to the 6V version with the 3s 18650’s, I have a cruel streak.
Previously I was driving it with the 9amp KD driver here
I’ve never had much luck getting consistent Amp readings with DMM’s but here is what it was showing at startup.
I have a HS1010a Light meter which seems to give figures roughly in line with others for CD maybe even a bit low.
I really only use it for my own comparative testing.
A stock K40M reads roughly 62,000cd at 1m calculated back from 6m, so i think its in the ballpark.
The 9amp driver with 3 AW IMR’s pulled 118,000 @ 30sec’s, pretty sweet.
No where near the overall output of my modded X100 but way more compact.
For me anyway, its a really good balance of flood & throw.
I pulled the old driver last night & fitted the BLF17DD Zener.
So far so good, although I did hear it scream in pain when I flicked it on high.
In all seriousness though, first impressions are, it gets hotter faster.
Light output by eye seems roughly the same maybe a bit more.
The biggest thing of note is the tint shifts on high from a warm white to a very cool white.
I have 3 sets of 18650 IMR’s to play with, AW 2000mah, Samsung 20R’s & Efest Purple 2500’s.
The tint shift is most noticible with the 20R’s.
Mucked around with it for an hour or so last night & its still alive.
Seem like quite tough buggers the MTG2.
If I get a chance tonight i’ll take some measurements.
Cheers.
Just did a quick Kcd Test & its a bit of a fail at the moment as one probably would expect.
Throw has dropped to around 90,000cd & it gets way hotter faster than previously.
Might muck around with a dummy cell a bit before the 9V MTG2 arrives.
I’m quite surprised its still running after such abuse.
Cheers.
Thankyou Sir.
Twas New years Eve & thought a Firework stlye Failure may have been quite spectacular.
Unfortunately due to the toughness of the MT-G2 it was not to be.
Cheers.
So did you manage to measure current when the emitter got that blue? If I remember well when I did MT-G2 output tests, even at 16A the tint shift was not that obvious . BTW at that current the output was way less than maximal (max is at ~11A, as good as max is 8A)
Apologies Guys, for some reason I didn’t get notification of new posts in this thread.
wight, unfortunately Cutter doesn;t come back from their Christmas break until the 19th Jan, so I’ve been patiently waiting.
So we’re nearly there.
Ive given it a few runs with a dummy cell in the meanwhile, seems okay, however I think out put could be down a tad.
djozz, no unfortunately I didn’t test the amps when running 3s.
I wouldn’t say it went blue, just tint shift to way cooler then back on lower modes.
Biggest thing of note was the heat, even in lower modes.
I fell the extra volts are to blame not a high amp draw.
By the way, I am an absolute novice with electronics, so dont give any weight to my findings (disclaimer)
However one thing for sure,I wouldn’t like to have done this in a host without a lot of thermal mass.
Cheers Guys, thanks for the interest.
With an LED voltage and current become inextricably linked. Take a close look at this post by djozz with a graph showing MT-G2 voltage vs current. Follow the blue line, ignore the red one. Note that as voltage increases (blue line goes up) so does current (blue line goes to the right). This relationship is always present; there is no avoiding it.
What I think you probably saw were your cells taking a big 20A-25A+ beating while producing a ton of resistive losses in all areas of the wiring, but especially in the carrier. You did bypass all springs, right? There would also be losses in the FET, in the traces and vias on the driver’s PCB, in the traces on the MCPCB, and in the switch.
Note that all these resistive losses cause voltage drop across those things where the losses occur. As we saw above, the voltage controls LED current. Less voltage means less current. Therefore these losses are what keeps your current down in the range where the emitter doesn’t pop.
. BTW at that current the output was way less than maximal (max is at ~11A, as good as max is 8A)