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Convoy S2+ has a challenger ( Nemo )

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#41 UlfW

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Posted 17 August 2020 - 16:36

If there is a need for a small area illumination that is even a rigid short light guide like this can be used:
https://www.ebay.com...ar=691643939436
For some reason I have one of those and decided to design and 3d-print a suitable adapter.
I made it slightly longer than the combination of the reflector filter and rubber ring to maintain the pressure on the LED's metal-PCB.
Attached Image: IMG_2202.jpg

The light-guide fits snuggly into the hole and ends just above the LED's lens, coupling almost all UV-light into the guide.
Attached Image: IMG_2203.jpg Attached Image: IMG_2204.jpg

At the end of the light guide the UV-light is very intense, almost as bright as directly above the LED's lens, then decaying quickly with increased distance.
Attached Image: IMG_2207.jpg

During the first fitting of the parts I leaned that the white bezel around the LED is made of plastic and just pushed into place.
It's purpose is to guide the LED and reflector to an optimal position. It came off as the hole in the 3d-print by mistake was slightly too snug, as well.

The LED's PCB came lose and I noticed that the cables were long enough to allow adding some quality thermal paste between the PCB and aluminium structure.

Edited by UlfW, 17 August 2020 - 16:58.

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#42 Andy Perrin

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Posted 17 August 2020 - 16:41

That is a nice build. Based on Stefano's experiments with burning things, I am not sure I would leave the end of the light guide on the paper like that!

With such a high intensity, I bet you could see some interesting fluorescence in any material that can stand the heat long enough for a photo.

Edited by Andy Perrin, 17 August 2020 - 16:42.


#43 UlfW

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Posted 17 August 2020 - 16:55

I agree, only long enough to take the picture!!
The intensity in the light spot is rather even but decays fast as the spread angle is wide.

BTW I used ABS for the 3d-print. The melt point is rather high and the LED would be dead before the plastic melts.
The printing temperature was 245°C in the extruding nozzle.
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#44 Stefano

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Posted 17 August 2020 - 17:03

You can always add a lens to have a narrower beam. I bet you can feel heat on your skin in front of that light guide. It looks like you are spraying light from the tube. I wonder what people would think seeing someone illuminating flowers at night with that thing.

#45 Andy Perrin

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Posted 17 August 2020 - 19:07

Many people have seen me out taking photos at night with the tripod and all, and I've yet to get even a question! I think people are hesitant to approach.

#46 dabateman

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Posted 17 August 2020 - 22:28

View PostAndy Perrin, on 17 August 2020 - 19:07, said:

Many people have seen me out taking photos at night with the tripod and all, and I've yet to get even a question! I think people are hesitant to approach.

If you really want to keep people away. Get a $30 hazmat suit off Amazon and a Geiger counter when your out at night taking photos.
If someone comes close sweap them with the Geiger counter in lowest or calibration mode and shake your head.

Edited by dabateman, 17 August 2020 - 22:29.


#47 Cadmium

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Posted 19 August 2020 - 00:28

Update to my previous post:
https://www.ultravio...dpost__p__38256

The 42mm to 52mm step up ring doesn't have enough thread depth to screw into the front of the Nemo. The Nemo threads start at about 2+mm inside the front.
Have to find something with longer threads.

#48 dabateman

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Posted 23 September 2020 - 05:37

Have you found a good battery for them? Something Ulf recommend with low resistance.

#49 Cadmium

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Posted 23 September 2020 - 11:19

I have no idea. Nothing to compare. These are the first and only 26650 I have so far. These work fine. I purchased these batteries separately from the 'Nemo' torches.
Ask Ulf for battery test comparisons and suggestions.
I have tried and compared many 18850 batteries for the Convoys and MTEs, some of which are inexpensive, and others are premium quality, and I have not noticed any difference between them in the brightness or run time.
I often use the Convoys for 45 minutes, and get to compare.
Here is the place John recommended years back. I have purchased some premium batteries there.
https://liionwholesale.com/

#50 UlfW

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Posted 23 September 2020 - 12:00

I have been playing with the idea to create an end-cap for the lamp head, containing a DCDC-converter and connection to a suitable USB current source like a Power Bank or USB adapter.
That can be handy for more permanent shooting setups, lighter and smaller than the whole torch with it's battery.
Then there will not be any risk of losing intensity to a low battery voltage.

The DCDC-board in the picture fits the inside diameter of the battery tube or in this case end cap.
It can deliver more than the needed 1.8A and step the 5V down so an optimal 3.8V after adjustment.
Attached Image: IMG_7964.jpg

The cap can easily be 3D-printed and I think I will give it a hole with a 1/4" camera-thread, on the side, for mounting on something like a small ball head.
The rather fine threads on the lamp head will not be possible to 3d-print well for me, but I can make a well working self threading structure.
The easiest way to build this is with a fixed USB-cable, exiting at the backside of the cap.

I am open for suggestions and opinions about this idea.
Is it usable for others than just me?

If it turns out to be easy to make and build, I might make a few more than the two or three I need, myself.
The materials cost is not very high.

Edited by UlfW, 23 September 2020 - 12:38.

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#51 colinbm

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Posted 23 September 2020 - 12:19

Looks good Ulf

#52 dabateman

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Posted 23 September 2020 - 16:18

Ulf,
Yes I might be interested in 2 if the cost is low.
Now I have tried a clamp to the battery compartment. But constant power would be nice. I think I am using either a #1 or #2 halex hanger clamp.

#53 Andy Perrin

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Posted 23 September 2020 - 16:23

I like the 1/4" thread idea. It would be nice for an at-home setup where you can use a mini tripod or something to point it and a USB hub to power it (and everything else).

#54 SteveE

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Posted 23 September 2020 - 17:56

I really hope your printed cap works. However, I suspect you may run into thermal problems. I think that the reason they have stepped down the power from what the LED is capable of is that the stock cap cannot adequately dissipate the heat generated by a higher power level. 10 watt LED microscope illuminators have either big honking finned heat sinks or fans. A printed plastic cap will not conduct heat away as well as the stock metal cap.

Edited by SteveE, 23 September 2020 - 17:57.

- Steve

#55 dabateman

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Posted 23 September 2020 - 17:58

Yes mine is mounted with a Halex #2 hanger clamp.

Attached Images

  • Attached Image: 0923201355a~2.jpg


#56 colinbm

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Posted 24 September 2020 - 01:00

Ulf, what is the fault with the 'Nemo' besides that it isn't 15w as advertised ?
There is the battery, 26650, of different technology & voltage, to the 18650 battery that we have used before.
The driver has 5 constant current IC's at 350mA which equals Cf 1750mA.
How is the max voltage established without the Vf being known ?
Col

#57 Cadmium

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Posted 24 September 2020 - 01:22

Something I don't like about the 'Nemo' is the back end battery cap. It is hard to remove, it has an O-ring, once it is screwed on all the way, it is hard to remove because it has no gripping texture to it.
Minor, perhaps, but the torch should have texture to that cap, such as with the Convoy's.

#58 UlfW

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Posted 24 September 2020 - 04:25

View Postcolinbm, on 24 September 2020 - 01:00, said:

Ulf, what is the fault with the 'Nemo' besides that it isn't 15w as advertised ?
There is the battery, 26650, of different technology & voltage, to the 18650 battery that we have used before.
The driver has 5 constant current IC's at 350mA which equals Cf 1750mA.
How is the max voltage established without the Vf being known ?
Col
I am not really sure how you define fault here, but let me answer your questions:

The build quality is not all the way up to the level of the Convoy is some aspects, but not bad at all.
Some differences are not at all important for the function, like type of anodisation and quality of the shipping box.
The design make it much easier to reconfigure and adapt for other purposes than the Convoy.

I think the LED is a 10W type, not a 15W but that is impossible to know without knowing the LED type.
The LED is driven a bit conservative and not to the full 10W due to that there only are space for five constant current drivers on the driver board.
Also A higher power might give too much problems with the mechanical design with the cooling of the LED.

The 26650 battery is just a bigger battery size with more volume that gives space for more capacity and a potential to have a lower internal resistance.
As higher power consumes more energy that is a logical difference.
The technology and voltages are the same, but the power and current capacity is higher.
Compare it with this:
Nobody would use a moped tank when designing a road train engine. :wink:

There are other sizes but even less common that the 26650.
As long as the battery chemistry is the same as the usual batteries LiPO it will work.
You could use a 18650 together with a plastic size adapter the gives the shape of a 26650.

The Vf of the LED is known from the wavelength it emits.
That is a property of the semiconductor technology used.
We also know the lamp is using five linear constant current drivers.

If you by Vf means the minimum required battery voltage that is found in my post in you topic.
https://www.ultravio...dpost__p__38385
Maybe I should try to merge some of that information into the main topic, to have everything important in the same place.

Edited by UlfW, 24 September 2020 - 04:28.

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#59 colinbm

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Posted 24 September 2020 - 06:17

Thanks Ulf
These 26650 batteries are only getting 4.05 volts after charging with the 'Nemo' charger.
The 18650 batteries I have & charge on other chargers get up to 4.2 volts.

#60 UlfW

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Posted 24 September 2020 - 08:27

View Postcolinbm, on 24 September 2020 - 06:17, said:

Thanks Ulf
These 26650 batteries are only getting 4.05 volts after charging with the 'Nemo' charger.
The 18650 batteries I have & charge on other chargers get up to 4.2 volts.
That is not related to the size 26650.
It can depend on the charger or individual battery.
The chargers delivered with the Nemo looks like junk.
I never even tried them.

I use a MiBoxer C4 Plus
and have an older MiBoxer C4

I think the MiBoxer C4-12 is really nice too
https://www.ebay.com...miboxer+c4+plus

Edited by UlfW, 24 September 2020 - 09:27.

Ulf Wilhelmson
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