NUBM44 handheld advice

[niiii]

Hello everybody, I'm planning to build nubm44 handheld laser. I found somewhere that it can output 7,9W @ 5.5amps but Im wondering what host should I use. Using survivallaser c6 or s4 host with so small heatsink would be very bad idea. Looking forward for your replies.

 

[Alaskan]

I'd use at least two 26650 batteries and a huge heat sink on your pointer, huge compared to most pointers. I don't think it would be too unwieldy, but the heat sink I'd use is one which can both soak up and transfer its approx. 15 watts of heat to the air if you want much run time, some members use massive copper blocks (rounded, of course) as a heat sink which can allow a fair amount of run time without fins, but to do it right I believe in fins and lots of them. There is a member here who can make just about what ever host you want at a good price; Ehgemus. Ideally, you would have a copper center core to the heat sink with a layer of aluminum over that with deep fins to increase the surface area to allow a better transfer of the heat to the air, but not necessary. Another member; Sinner, has experience machining that type of host but his prices are higher for that kind of work.

Edit: I better add more, I'd also have the host designed to allow the driver to be mounted somewhere on the head or body of the host to heat sink it well too, having a constant current driver inside of the Aixiz module at this current level without heat sinking won't be a good thing, you would severely limit the run time. Of course, you could mount everything in a moderately sized pointer, put the driver inside the laser module and it would work, but have very short run times with the risk of damaging the diode, or possibly the driver, if you run it too long.

For myself, I'd try to find a host with a heat sink at least as big as the one shown in this thread with lots of deep fins:

http://laserpointerforums.com/f45/z...-520nm-build-3-elements-glass-lens-93923.html

 

[niiii]

thanks for your reply, are 26650s better than 18650? or just have more capacity? I prefer to use 18650s because I dont have any 26650s, but that wouldnt be problem to buy some. I saw some hosts from sinner that I really like, I think I will contact him as soon as I get the module. Id like to get as best as possible host.

 

[RedCowboy]

Hello everybody, I'm planning to build nubm44 handheld laser. I found somewhere that it can output 7,9W @ 5.5amps but Im wondering what host should I use. Using survivallaser c6 or s4 host with so small heatsink would be very bad idea. Looking forward for your replies.

5.5 amps is too much 4.5 amps is useable, any more will soon be converted to internal heat as output falls fast at 5 amps and over.

 

[Alaskan]

26650's have more capacity and are normally rated for higher current. You won't need the higher current rating of most 26650 batteries compared to many of the 18650's anyway which can have plenty, but I prefer them because under a heavy load their peak voltage doesn't sag as quickly. Are they really needed? Unless you have some bad or low current 18650's probably a waste of money if you can make do with those, but there is no way I would run this diode on less than the 26650's myself, I like the extra capacity and their ability to pull large amounts of current without their voltage draining down as fast.

So, my advice is, get a host which can hold 26650's, I don't think you will regret it unless you just don't like the larger diameter. Much depends upon how you operate the laser, for short duty cycles, which you will likely be force to use anyway unless you have a very good heat sink, it won't make any difference.