Manker MK37vn - 1st TIR SBT90.2

[twistedraven]

Just got my MK37vn in from Vinh. As far as I know all he does is a delid of the SBT90.2, which improves output and throw by ~5-7%.


First thing first is, the knurling on the tailcap and body is really rugged! Almost too sharp and course, but definitely very grippy. It digs into your skin quite well-- good or bad. Overall size and heft, plus not being top heavy from a big head makes the light feel very nice in the hand, though.


The beam profile is more reflector like than I thought, and it's like a narrow+deep reflector type beam profile, meaning smaller hotspot, and larger corona. There is definitely some spill, but not as noticeable as as a traditional reflector, because the edge of the spill is a little more diffuse than the hard edge of a reflector. Compared to the optics in my MF01/MT07, I can see noticeable spill. Compared to a traditional reflector, the spill isn't anywhere as bright however, but still noticeable. So I wouldn't say the output is almost entirely in the hotspot, because there's definite spill this optic produces, but it's a far-cry from reflector spill. One cool thing though, is you get very little off-angle glare as another person looking into the light compared to a traditional reflector, because of the way the optic is designed. There is also a ring around my corona as well,. On the positive side, the light seems very well focused, and there's distinct pedal shapes on the corona itself, that are equally spaced out and sized, meaning great centering.


Comparing turbo burst to the MT07, which is modded to have 7 White 2mms (cslpm1.tg), putting out 7700 lumens and 115kcd (Vinh's measurements), to the MK37, which has 1 sbt90.2, outputting 5100 lumens and 252kcd. The 1 sbt90.2 in the larger, beefier MK37 body gets hot much faster, and is almost too hot to touch at the heatsinks at around 30-40 seconds. The 7 White2s in the MT07 stay cooler longer. This makes the turbo on the MK37 purely a burst feature, and only useful for 30seconds to 1 minute at a time unless in freezing conditions, and that would only probably extend that runtime by mere seconds. The SBT90.2 is such a power-hungry LED, I just don't think it's a sensical choice for any host that's under the size of say, a BLF-GT. If manker's numbers are to be believed, however, and if the light can sustain constant output at 1100 lumens while achieving 40kcd, that seems to be the sweet spot for this light.


The UI was a bit disappointing to me. On paper it reads fine, but I really miss the option to cycle to regular output levels from a long press from off. From Anduril or Zebralight UIs, you can long press from off to enter moonlight, or the lowest mode, and keep it held down to progress in brightness. Doing so on the Manker leaves you on moonlight cycling purgatory. Double click from off or while on still gives turbo however, which is very welcome.


These are all initial impressions without outdoor use, but so far they're mixed, mostly due to UI and beam profile. (I knew what I was getting into with the SBT90.2's heat output based on my experience with the Acebeam K75.).


I can't wait to take this outside and let it shine! I will also do a runtime test with the 1100 lumen mode to see if it can handle the heat.

Edit: doing the runtime test at 1100 lumen setting, and the light is only warm after 15 minutes, and output seems to have stayed the same over that amount of time, so having 1100 lumens and 40kcd that seems very sustainable in something the size of the MK37 is really nice!

 

[knucklegary]

Thanks for first impressions!

I feel the same about Manker moonlight (purgatory lol) UI. While it's okay on a E03H, i find it a nuisance on my MC13

 

[twistedraven]

On Zebralight, holding down the button while in any output automatically takes you to moonlight, while Anduril's ramping is fast enough to decrease output when you need to. This is nice for dimming the light if there's people or something else nearby that requires it. Anduril defaults to ramping back up after a small pause in clicks, which I quite like. With the Manker UI, no matter the pause, you're stuck in the down-stepping of outputs until you hit its lowest output. These are nitpicks for if you were to use the light for hiking etc, or general usage, but on a pocket thrower like the MK37, I don't see them as being too much of a detriment, since the use-case is much different. For instance, on the MK37, I'm perfectly fine keeping in 1100 lumen mode, then having the turbo at the ready whenever. It's not the kind of light I'd be using on a trail with people nearby.

Uncooled and indoors, turbo makes the cooling fins warm at 20 seconds, hot at 30 seconds, and too hot to touch at 45 seconds. There's a noticeable difference in temperature between the cooling fins and handle, meaning the cooling finds are soaking up the majority of the heat. This makes me believe that Manker's thermal regulation is more lax, allowing for only small degradation of turbo output in at least the first minute or so, which is nice. Reading Zeroair's review of the Imalent RT90 for example, shows its turbo to drop from 4600 lumens to 2700 lumens after 30 seconds, and down to 1000 lumens at 1 minute.

 

[twistedraven]

https://es.aliexpress.com/item/3295...earchweb0_0,searchweb201602_,searchweb201603_


This 2 degree optic looks very similar to the one that's in the Manker MK37. The beam profile the MK37 has with the SBT90.2 is less than ideal imo-- small hotspot, huge corona, something which you typically see of reflectors that are too narrow/deep for their led. Seems like this type of optic would benefit greatly from a much smaller die. (W2.1 perhaps). The performance with SBT90.2 is still really good though.

 

[Patriot]

Raven, I enjoyed your write up on this light and you had me laughing about the "moonlight purgatory" haha! I guess it's like anything else though, if you're used to Anduril or Zebra, like most of us are, it's easy to revert to those habits. I can't say that I altogether agree with your assessment of the usefulness of the SBT90.2, mostly because I don't think that a LED has to be able to run at maximum specifications continuously, in order to be sensible. I only say this because I'll run lights the K30GTvn or T27vn90 using many different levels of output while on a desert night hike and I've never thought to myself... "I wish these light could run and maintain 5000+ lumens continuously." Mainly because I haven't had the need for high continuous output, with any regularity. When I have a need for maximum specs from the SBT90, it's usually for a couple of seconds, ranging to a couple of minutes and both of them will do that. Maybe in a different scenario, like using as a search light from a vehicle, I'd be in more agreement. More specifically, if one needs 200-300+ Kcd from a relatively compact light, and it's just not possible from a multi-emiter of similar size, the SBT90 becomes the obvious choice and perhaps that's what it all comes down to, needs and requirements.

Thanks again for taking the time to post about your new light. A lot of people don't, so I always appreciate when owners take time to share. It's of the things I really enjoy about the forum.

 

[Skylumen]

I don't go into details for each build anymore since they are just too much info for the general and mostly confuse the purchase. Listing the detail mods on the store page will get repetitive fast from items to items and are mostly meaningless to the buyer. I dont even talk about current draw and efficiency anymore like I once did. Most of the folks that buy from SkyLumen.com only care about one thing. What's the performance numbers.

MK37vn mods are not intensive compared to others Sky Lumen builds. This is what $14 gets you over stock $140.

- LED re-flow and De-Lens. This ensure the LED has the adequate and leveled amount of solder bonding as well as LED +/- wires bonding. A poorly mounted LED will see quick dip in output as the LED overheat. A level mount plays a key with centering hot spot in the corona. I also sometime add extra solder to float the LED higher up into the reflector/optics for a more focused hot spot. For the MK37 optics the higher the LED the more defined the hot spot becomes. De-Lens is done to up the output 5-10% with variance. May be negligible gain but I do like the tiny bit whiter tint it brings. I also notice that sometime the Lens box could get fogged up with use likely due to a burnt contaminant. Removing the Lens box AKA De-Lens eliminate this potential issue that is only to relevant the SBT90.2. All win win from what I can cell. The builder just need to handle the LED MUCH more carefully after De Lens. Also make sure De-Lens is done last so the die surface n bond wires are least exposed to physical damage.

- New solder paste added as necessary.

- Second/double springs soldered to ensure strong pressure and least resistance. Only need bypass wires for linear drivers.

- Lube threads as necessary

- Quick Turbo function check

- Sky Lumen Warranty

* Stock light is fully glued at Bezel & head to body. Lots of heat is needed for disassembly. I left everything unglued after the mods for ease of future service by me. Do not disassemble the light body from the head as the battery handle wires can break if not wounded correctly after removal and reassembly.

 

[Skylumen]

Spoke To manker about mode spacing and made some recommendations..We will see...

 

[twistedraven]

I really do enjoy the 1100 lumen level on the MK37. It seems to be the highest amount of lumens it can take and sustain. I've never been a fan of any light that has more than 3-4 levels of output though, and the MK37 has more than I'd consider ideal, but I just find myself using it as 1100 lumen or turbo, and never touch the other outputs.

Of note, Manker is also soon to be releasing the U22 v3, which is essentially the same emitter and optic as the MK37, but with just a 1x21700 battery body. Acebeam's L18 also seems to use the very same optic as well. It goes to show just how good the performance of the optic is, allowing for smaller lights with same throw performance. I personally don't think the U22 v3 will have quite enough mass to handle SBT90.2 on turbo for a satisfactory time, but I think Acebeam's approach with the Osram emitter is the way to go. Acebeam's L18 generates the same ~250kcd using the CSLPM1 (W2), as the MK37 does with the SBT90.2 delidded.

 

[richbuff]

Post #26: Bookmarked! https://www.candlepowerforums.com/v...-TIR-SBT90-2&p=5436647&viewfull=1#post5436647

Thank you for the reminder explaining why it is important to have a light pass through your hands. But personally for me, not the most important reason.

The one thing I care about the most is when it comes to flashlights is that they pass through Vinh's hands before I get them. I have 37 such lights. That includes two Vn54 lights that I ordered for the express purpose of giving to friends. I have four non-Vn54 lights that I purchased in the Fall and Winter of 2014 from GG before I had the blessed fortune of discovering Vinh. That happened when I realized that GG would not be carrying the Meteor M43. So, I searched and found Vinh! Two of those lights, the MM15 and MMU-X3, I did purchase the full tilt Vinh version of the light.

 

[kolchak]

The SBT90.2 is such a power-hungry LED, I just don't think it's a sensical choice for any host that's under the size of say, a BLF-GT.

First thank you for your very informative review!

I love my two SBT90.2 modded lights from Vinh. My edc is a tiny Eagtac TX25C which puts out a ton of light and is very throwy. The other is a K30GT. Both have driver VNX2 and I've never had to turn either off or down due to heat issues. Sure the Acebeam gets hot, but I've run it on turbo for several minutes at a time with no issues and not holding it with the (not great imo) provided handle either.

I also am a big fan of TIR lights - the spill is much less blinding and fades rather than the sudden cut off of reflector bases throwers. Combined with a hot spot that focuses narrower and far away, like a Surefire weapon light, one's near surroundings are much easier to see and there is far less 'bounce' of close objects. This imo makes it a better light for tactical purposes, hiking and walking and the such. Great for using in the woods for example or in a crowded urban environment.

 

[cclight]

Of note, Manker is also soon to be releasing the U22 v3, which is essentially the same emitter and optic as the MK37, but with just a 1x21700 battery body.[...] I personally don't think the U22 v3 will have quite enough mass to handle SBT90.2 on turbo for a satisfactory time

Manker numbers for both show that there's a big difference in output with the Osram green. It's likely there will also be a big difference with the SBT90.2, if it is released. I like the beam width of the MK37 a lot more. I like floody beams and only use a thrower for brief moments to see distant objects. The MK37 may reverse this: I could use it often and only use a flooder for short ranges/indoor. I've tested with a flashlight I have with a similar cd/lm, and it seems to work well.