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Yobresal built 1.8W 445.. Burning Vid






Indeed..

I know I'm a noob to this whole realm of handheld cheap DIY lasers, but I have been an enthusiast for a long time, even working with them in years past.

Clean optics are paramount..

I take good care of my equipment.. But it stands to be said.. Clean your lenses (gentile, gentile..LOL) Clean optics are cool optics, and like throwing boiling water on a frozen windshield, a speck of grit on your lens will heat up, and asplode the whole crapshoot..

Thanks for the reminder.. :)
 
Nice vid. As I am sure you noticed the laser gets hots being left on that long. I am sure normally you don't run it for a minute at a time. 30 seconds is a good duty cycle for this super powerful one in such a small host.
 
Not really Yob..

The Diode seems happy, the output stable.. The diode itself, pressed into a copper heatsink is *huge* for migrating heat off the factory package..

Its all about thermal management.. We know these LDs can take the current, its just our job to wick away the heat..

And FWIW, a Aixiz module, set-screwed into an aluminium heatsink is good, but its like an order of magnitude less than what you can sink from a diode housing pressed into a heatsink.. Al is good, Cu is better..

Your Cu heatsink, with that LD in it is perfectly happy at duty cycles of 60 sec on, 60 sec off..

I've even taken it to >180 sec on.

If the driver is screaming, I dunno.. Its back in the host, and I don't want to tear the warranty stickers to find out..

Regardless.. This thing rocks.. Maybe more than even you'll give it credit for.

I want this in a labby, except I want 100% duty cycle..

Fortunately, with a labby, fans, TEMs, even phase change cooling becomes possible.. :D

:lasergun:
 
But.. Let me backstep here a bit..

Yes.. It is very important to understand that these LDs generate a *lot* of heat, and the smaller / lighter the heatsink, the shorter the DC (or Duty Cycle) you can expect.

This 1.8 seems to be pretty well built.. Press fit LD to a CU heatsink.

You gotta remember, I'm more used to sinking 70 watts off a 8X10mm chip..

Thermal management is key, but you did right on this build.. It can handle a lot..
 
mendnwngs said:
And FWIW, a Aixiz module, set-screwed into an aluminium heatsink is good, but its like an order of magnitude less than what you can sink from a diode housing pressed into a heatsink.. Al is good, Cu is better..
Click to expand...

You bring up a good point, though I wonder how much that set up would be improved by not just relying on the side opposing the set screw to transfer heat. What if you coated the aixiz module with thermal grease, enough to fill the gap between it and the aluminum heatsink, and then did the same for the heatsink into an all aluminum host?

Direct pressfit into a Cu heatsink is obviously better, but I wonder by how much when compared to my scheme above.
 
The 1.8W video'ed above that I got from Yob is a A140 LD press fit into a Cu radial heatsink..

I have since played with A140 diodes pressed into Aixiz modules, that I set-screwed into Al heatsinks meant for a C6 host..

The LDs in the module, couldnt hold a candle to the LD to Cu heatsink I got from Yob.

Its all about surface area.. The more surface area you can get in contact with the sink, the better off you are..

I work with systems that are pushing up to 20,000 amps. (Yes, 20KA) through 4" dia stainless rams.

In my world, the ram-to-tool thermal, and electrical connection is everything, so we use pretty exotic graphite materials. (google Grafoil, or graphite Van der Waal force)

Point being, its all about thermal contact.. Thermal grease is good, but only to fill the microscopic voids between two mating surfaces.. A 12mm module in a heatsink with a set-screw leaves gaps around 80% of the circumference. I can see this when looking through a module mounted in a 12mm hole in a heatsink (I can see daylight around most of the module)

This isnt transferring a lot of the heat to the sink.. IMO, A press fit diode in the actual heatsink is a much better, if not less convenient option.

We're doing things with these LDs way beyond their designed use.. The least we can do for them is cool them as best we can :)
 
Good stuff, I'm glad you have a good understanding about heat sinking and the new for it in devices of this nature. The rule of thumb that I follow with my lasers as far as duty cycle goes is if the laser feels more than warm shut it off. Essentially your laser is a 2W and it is the smallest size heat sink I would dare put a 2W into. You do have the huge advantage of having a copper press fit heat sink. Much better than the other option for that host.
 
Not at the moment but I will have a couple more available in a week or less.
 
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