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NUBM44 Modular Build

Andrew124C41

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I have experimented with a number of ways of dinner this and I am always wanting to improve on previous builds.

One thing I feel is important is to be able to easily troubleshoot problems which is difficult if the driver is soldered directly to the LED pins or if the build uses very short wire runs and is cramped. I like to use an inductive, clamp type meter that Redcowboy recommended but you have to be able to get the clamp around one wire.

I also want to easily be able to swap out parts...mainly the driver and the LED if one goes south on me.

20210406_111758.jpg

The heatsink was made by Lifetime17 as was the copper driver shelf you see below it.

He made the copper driver shelf with a 20 mm diameter to fit behind the 20 mm DTR module containing the LED. I am using a copper driver shelf because copper is more efficient at transferring heat than aluminum. (I just learned that the difference is significant.)

I am using an ASC4500 driver mounted with a special blend. MG 2 component thermal adhesive with a smidgen of Fujik and Silicone thermal compound. The result is a good bond, but if necessary, I can remove the driver without damaging it. The heat sink on the top of the driver is not necessary...but I have a bunch of them lying around and, well, what the heck. It is set at 4.5 amps.

The driver has 24 G silicone leads with a Deen's micro polarized connector in the battery end and a non polarized one in the LED end.

(I used to use the polarized ones so my maglites have them already...but I am moving to the non polarized ones which are easier for me to configure for testing. I have special leads with these connectors for my dummy load and power supply for testing.)

The 20 mm module is the NUBM44 and the 12 mm is an 07 465.

The heatsink has 3 setscrews. 1 for the 20 mm module, 1 in the middle and one on the end to hold it to the maglite.

I have 2 maglite mods that Jarob did for me. He still does them but without the battery monitor. The monitor changes color when your lipo cells drop in Voltage. Here is the link for the Monitor.
Here is the finished laser.
20210406_111621.jpg

We moved not long ago, and I have yet to unpack my laser power meter. When I do, I will post the result.

I am trying a G8 lens for the first time.

What if anything would I do differently if possible?

If Lifetime17 can do it, and much more labor would be involved, I would make the heatsink a larger diameter and instead of superficial grooves, he would make deep grooves creating thin heatsink find which would increase the surface area and increase the rate of heat loss.

I would also make the heatsink longer. Why? Because I would also like to make the copper driver shelf 20 mm aspect a bit longer. This would increase the contact surface area with the heatsink.

Of course, the other way of doing this would simply to let Lifetime 17 make the entire host, heatsink and all.

Getting everything into the heatsink after putting thermal paste on both the 20 mm module and the driver shelf was a little tricky.

I would move the setscrew further back so that the driver shelf would be right at the end of the 20 mm bore aspect of the heatsink.

This might make putting everything in a bit easier.

One has to account for the wire and the connectors. I did not want them to scrunch up too much.

Finally, I have an extension for my maglite so it will take 3 32650 cells. The Felongs I have been using have good capacity but lag a bit in voltage. They are simple lipo chemistry.

I am expecting some 32650 lithium Iron Phosphate (LFP) cells to arrive today. They can deliver 10 amps. Their nominal voltage is 3.6 V. We will see how they perform.

EDIT: The 32650 LFP batteries I ordered turned out to be 32700 and the 3 32650 Felong batteries would not fit in my maglite. It was a 2 D cell for which I purchased an extension....but 3 of the 32650s would not fit.

I wound up using 2 of the 32650s and 1 26650 until I can get more 26650s. I also swapped out an sxd for the ASC4500 but left the setting at 4.5 Amp.

With either a G2 or the G8 which I had never used before, I am getting 7.4 W which I am satisfied with.

20210409_000553.jpg


EDIT 2: I picked up some good IMR 26650 batteries from the wholesale place in PA.

How to fit them in a D cell-sized Maglite?

A trip to my local Giant Supermarket, just to the right of the fridge with the Kosher Kalbasa, there it was....
32650 to 26650 downsize tubes!

Tube.jpg

7.5 inches long, it fits perfectly! You never know what you find in your local supermarket.

What you say? Why would 32650 to 26650 downsize tubes be next to Kosher Kalbasa? How should I know?

Ok. I lied It was a bit more complicated than that.....but not much.

I went to our local hobby joint and picked up some thin polystyrene sheets. The guy recommended super glue. Forget it. Does not work. Two component epoxy.....not much better.

Turns out all that struggling was unnecessary. I just used a 26650 cell as a form and wrapped a single sheet around it and used duct tape to hold it. I used successive layers of duct tape and polystyrene sheets until I got the thickness I needed to fit into the Maglite.

The difference in diameter between 32650s and 26650s is only 6 mm in diameter.....a little more than a half centimeter. So, it does not take much material to get a fairly stiff and durable tube that fits into the Maglite.
 

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Andrew124C41

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ArcticDude...man you are fast on the draw! I just posted this a second ago!
 

cncyana

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Jan 7, 2012
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Hello,

Very nice build!

1) Can you show how you built the monitor and LED?
2) Can you re-link the monitor link? It doesn't work.
3) Connectors are good for changing diodes but are there any disadvantages to using connectors rather than direct solder connections?

Thank you.
 
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Andrew124C41

Active member
Joined
Jul 3, 2015
Messages
549
Points
43
Hello,

Very nice build!

1) Can you show how you built the monitor and LED?
2) Can you re-link the monitor link? It doesn't work.
3) Connectors are good for changing diodes but are there any disadvantages to using connectors rather than direct solder connections?

Thank you.
I did not put the monitor in. It was done by Jayrab and he is no longer doing it.
The monitor is no longer available. But this one is: Monitor
Only disadvantage is that they take up more space and you have to plan.
There is absolutely nothing wrong with direct solder and most guys here do it that way.
You can always resolder.
I just happen to like the connectors.
 

cncyana

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Jan 7, 2012
Messages
152
Points
18
Thank you for the info on the battery monitor. Just to clarify, does this build have a monitor in it? I wasn't sure if it was a new build without a monitor or you modified an older jayrob build which already had his monitor.

In general, if you were to put one in your build, I assume it would be wired between the Magswitch and the driver and only illuminates when the Magswitch is pushed on.

1) What is the dot in front of the rubber Magswitch button?
2) What is the approximate total length of your build?
3) How was the length of the heatsink calculated? Just by summing up: the length of the copper module + driver sink + extra to slide over the Magtube?
4) How many of the three set screws hold the heatsink to the Mag battery tube? Two? Is the set screw enough to keep the heatsink firmly fixed to the Mag tube? I ask because set screws are so small and the heatsink is so big by comparison, not to mention the heavy copper parts inside the heatsink.
5) Assuming you use thermal compound between the copper module and the heatsink, is it difficult to pull the copper module out the front when you disassemble it? Do you pull out the copper module by pulling the lens knob?
6) Was the Mag battery tube modified to accept the heatsink? In what way? Were the head threads on the Magtube machined off?

Thank you for showing this build - good pictures and info !
 
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