“REVIEW”: On The Road Z821 - Zoomable – 1x18650 – 940 lumens [Pic Heavy]

If you try temp sensor make sure mcpcb is populated with that tiny resistor at bottom or else it won’t work

Sure, I will ask led4power to send it with the resistor when he opens the store again :wink:

You mean on Hawkeye Focusing Fighting tactics light :laughing: They do exaggerate in description and I can bet they have hollow aluminium pill ass seen on plenty of models plus clasicc non anodized threads with crappy no name press fit switch (you know those white plastic switches with brass cover for spring?)

But maybe I am wrong…

No matter for pros and cons OTR Z821 is one of the best commercial available 1x18650 zoomie in a world. But still can’t you tell to OTR that it would would be quite fair that they put Osram White Flat inside with DTP board? That way 30$ price would be approved.
Lead group buy for OTR Z821 with mentioned ingredients and I am sure you’ll collect 500+ buyers in no time…

Hum, I’d be very surprised if you weren’t wrong about that :smiley: That is one of the reasons why this OTR stands out, even in “comparable” flashlights :stuck_out_tongue: It is not funny to mod one of those press fit switches :zipper_mouth_face:

Nor to add a shelf to the hollow pill :smiley:

I guess I’ve said in the Zooming Model list thread why I will not run a GB !
Please don’t get me wrong, but I guess that till now we’ve seen that OTR has a specific market (China), and normally they have very “specific choices” in what concerns leds. XML2 / XP-G2 has been their longtime preference.

The change in user interface, adding configurability, may be an opening in perspectives, but I am not sure how open they would be to invest in new Leds. Maybe I’m wrong this time.

Also, communication is sometimes not as “fast and clear” as needed to do a GB.

More than that, I know that besides that led, people would start begging for “this and that”, with W1 or W2, package or no package, and… I honestly don’t have the time or patience to negotiate endlessly. I do appreciate the work, time and effort that people running GBs and BLF projects have to make things “real”!

BTW, “this is the only ”pseudo-GB”“:[Group Buy] ***RovyVon Angel Eyes E300S*** - *[Discount: 20% /+50 Units = 25%]* ___CLOSED___ that I ever ran here on BLF. It is sure that other things got in the way by that time, but I’m not tailored for that kind of organization.

OK… But for that price it should at least have DTP MCPCB :person_facepalming:

Yes I had such results so in fact that is moonlight, ultra low, low and high… Middle mode is missing as I said in mine small review about month ago here. It should have middle mode at 1.8A current draw.

I will ask them if there is any possibility to have some of the changes suggested, be it the DTP or even the Osram :wink: But, I wouldn’t count with too much opening for that on their side.

About the data, sorry, I forgot you had measured it before :person_facepalming:
I linked your post above on the review, but I didn’t pay attention to the measurements.

Well, with the numbers, it becomes more obvious that the distance between medium and high is less “visible” than at sight (eyes, in this case). I believe they don’t want to push it “too much” to allow better runtimes, but it sacrifices some output :zipper_mouth_face:


BTW, yesterday I modded the Z821.

Like contactcr, I dismantled my Convoy S2 that had a led4power 4A-6A driver and Osram White 2 and put it in the Z821 :partying_face:
Whaaaat?!! I couldn’t wait till led4power reopens the store :stuck_out_tongue: :smiley:

I also replaced the tailswitch, for a forward clicky switch. I used the PCB & spring of the OTR M1 and soldered a FC switch bought from Simon. Tailcap is orange and fits better in colour.

I also added a screw-in pocket clip, that I “torched” a little bit to be more suitable in colour :wink:

On the head, I blackened the “reflector”, and as I didn’t have any suitable gasket, I added electrical tape and also GITD tape around the led to avoid contact between the solder and reflector, and also to avoid a ring around the led (every gasket I had was creating that).
Still, despite this, there are still artifacts…

I must warn that: I like the throw and output with the W2, but I guess I will replace it for a W1 later, because the rectangular shaped beam seems a bit awkward, at least indoor.
Also, I had to change the driver to CC instead of DD (even at 4A) because with a full battery the highest level was turning into BLUE :open_mouth: CC solved the issue, so beware of the configuration you use in this light!

Some photos below.

Hmm yours is turning blue with constant current set to >4A?

It was, on Direct Drive and fully charged battery (literally taken out of the charger).
Can it be some problem with my setting?

Oh with direct drive I am not surprised. I misread your post as anything above 4A turns blue.

Did you take any measurement of throw or try higher CC setting like 5A?

Well, funny thing is, I had it on the Convoy S2 with DD configured and it never happened :zipper_mouth_face:

It was turning blue even at 4A with DD. With CC it is normal :wink:
I can’t make measurements, I don’t have a clamp meter and my DMM can’t read too (no fuse :person_facepalming: ).

But I have it now configured to 5.5A, CC and so far no problem.
Also, when it was on DD, it got HOT in seconds (with full battery of course), and with CC it doesn’t heat that fast :wink:

“turning blue even at 4A with DD”

If enabled, DD is not limited by your settings in the driver config. It replaces the highest mode and acts like FET driver on turbo.

For testing I mean just lux meter test at like 5-10 meters. Clamp meter kind of pointless with CC driver :slight_smile:

Stupid me :person_facepalming: I read it on l4p thread some days ago and completely forgot it :weary:

That’s the reason why it was turning blue… :person_facepalming:

Ahh, lux readings! well, I don’t have many conditions in my house, but later tonight I will try to measure it at least at 5m. I will post what I have then :slight_smile:
The clamp could be good to check if it was in FET, with the OTR battery (to compare with other battery) :wink:

Yes it could turn blue because when DD it will draw around 14A of current!

Thanks to L4P I was probably first person in a world to test this White Flat 2 emitter with my redneck test(battery, lux meter, clamp meter tail readings) which is not so accurate as pro equipment but it is telling certain values:

Samsung INR 30Q FET Driver:
4.2V, 13.4A, 930 FC

4.0V, 12.5A, 950 FC

3.9V, 11.4A,1050 FC

3.8V, 10A, 1250 FC

3.7V, 9.20A, 1200 FC

3.6V, 8.20A, 1150 FC

3.4V, 7A , 1100 FC

It really is beautiful emitter but it will never go to mine single 18650 configurations because for best performance it should be hard driven.
And when driven on 4.5A old dedomed XPG2 will be better performer.

WF1 is different story… Only flaw is that it is very small emitter for larger aspherics but it should work more than fine in this OTR.

And man you gotta get yourself lux meter and clamp meter (30$ of investment).

Oh forget about that now I see that you have lux meter :beer:

BTW I have same light meter as you. Try to switch to FC mode. That way it reads much more accurate and it is very easy to convert FC to lux online.

5m measurements and convert…

I will bump mine up to full 6A CC mode and re-measure lux. Really want something closer to 100kcd out of this but I guess I will have to max out the LED with new driver or switch to NM1 to get that

Osram White Flat 1 + precoolimator lens.

66.5kcd, not much improvement

This host is not worth the complexity and cost of pre-collimator lens. I may try WF1 though.

Please try. It should be 20% brighter. So it should hit 100KCD which is extreeme thrower in that flashlight size. Do you remember those small 80-90 kcd lights that Saabluster(from CPF but he is member here too) was selling several years ago for 300-400$? At that time that was really extreme performance in small flashligt form factor. Well this should certainly surpass it in every possible way if you put WF1 inside.

Thanks for the measurements and the information on this luminarium iaculator :wink:
Well, 14A current may be a little too much for the led :stuck_out_tongue: No angry blue on this team :stuck_out_tongue:

I was going to get a UT201E clamp meter 2 weeks ago on a local store, supposedly on sale for half the price (23€) but when I reached the store it was sold out :person_facepalming: I felt disappointed. I will wait some more time, bad time to buy stuff now…

About my rough measurements (really rough, as I have no good setting to do this at home):
at 5 m, I got a) ~2290 lux peak, 2080 lux after around 15-20 seconds, and b) 206 FC, that then started decreasing.

Using the online calculator that you gently pointed me to,
207 FC = 2228.1294563l lux
2290 lux = 212.7479616 FC

2290lux at 5m = 57250cd

So, are the measurements wrong?

Driver is set to CC at 5.5A, the battery was at around 4.1V, and after being lit for a while (less that 1 minute), the light was 46ºC in parts of the head and body.
It gets almost too hot to hold when being pushed during some time.

I hope this helps in some way :+1:
And help me correct what is wrong !

Since you have different lux meter, LED, etc I dont really see any reason to think it’s wrong

I don’t think they are wrong… Possible LUX meter calibration variation :beer:
Whole BLF would need group buy of same type/same calibration luxmeter. That way we would have same results. Djozz would be right guy to take group buy since he is almost doctor for lux meters :wink:

Contactr got this before me lol :slight_smile:

But there are plenty of possible variables:

- Lens difference (only applies to glass lenses and performance may vary a lot)

- emitter brightness difference (someone gets lemon and someone strawberry)

- spring bypass (ignore that for Osram but it still matters for Cree emitters)

- Driver wire length&thickness (not much influence on Osrams just Cree)

- Mcpcb (DTP board really boosts things up)

- lux meter calibration

- Used 18650 cell

  • I can’t remember any more…

Edit:
About your luxmeter… I noticed that lux meter readings goes up if I clean sensor with wet wipes and microfiber cloth. But you can try to clean it with whatever you have. Mine is in dusty drawer and needs cleaning from time to time…